ETH Price: $2,679.67 (+0.54%)
Gas: 1.55 Gwei

Transaction Decoder

Block:
19290999 at Feb-23-2024 02:51:11 PM +UTC
Transaction Fee:
0.023867817501057991 ETH $63.96
Gas Used:
342,731 Gas / 69.640089461 Gwei

Emitted Events:

132 Uni.Transfer( from=[Sender] 0xf9699da649cad0ed4bd9152cab872f288d16fa88, to=AMMWrapperWithPath, amount=3349318600000000000000 )
133 Uni.Approval( owner=AMMWrapperWithPath, spender=SwapRouter, amount=79228162514264337593543950335 )
134 WETH9.Transfer( src=UniswapV3Pool, dst=SwapRouter, wad=12206417337253230110 )
135 Uni.Transfer( from=AMMWrapperWithPath, to=UniswapV3Pool, amount=3349318600000000000000 )
136 UniswapV3Pool.Swap( sender=SwapRouter, recipient=SwapRouter, amount0=3349318600000000000000, amount1=-12206417337253230110, sqrtPriceX96=4788476584186212589676979687, liquidity=291272776094289621344543, tick=-56126 )
137 TetherToken.Transfer( from=UniswapV3Pool, to=AMMWrapperWithPath, value=35867846473 )
138 WETH9.Transfer( src=SwapRouter, dst=UniswapV3Pool, wad=12206417337253230110 )
139 UniswapV3Pool.Swap( sender=SwapRouter, recipient=AMMWrapperWithPath, amount0=12206417337253230110, amount1=-35867846473, sqrtPriceX96=4295413433069723995470997, liquidity=3440002471308015603, tick=-196461 )
140 Uni.Approval( owner=AMMWrapperWithPath, spender=SwapRouter, amount=0 )
141 TetherToken.Transfer( from=AMMWrapperWithPath, to=[Sender] 0xf9699da649cad0ed4bd9152cab872f288d16fa88, value=35831978626 )
142 AMMWrapperWithPath.Swapped( [{name:source, type:string, order:1, indexed:false, value:Uniswap V3, valueString:Uniswap V3}, {name:transactionHash, type:bytes32, order:2, indexed:false, value:14D0BE66B8B46B3CFB62DE44AB372781B8D7501699CB766CEEF6020EC1F98532, valueString:14D0BE66B8B46B3CFB62DE44AB372781B8D7501699CB766CEEF6020EC1F98532}, {name:settleAmount, type:uint256, order:3, indexed:false, value:35831978626, valueString:35831978626}, {name:receivedAmount, type:uint256, order:4, indexed:false, value:35867846473, valueString:35867846473}, {name:feeFactor, type:uint16, order:5, indexed:false, value:10, valueString:10}, {name:subsidyFactor, type:uint16, order:6, indexed:false, value:0, valueString:0}], order=[{name:makerAddr, type:address, order:1, indexed:false, value:0xE592427A0AEce92De3Edee1F18E0157C05861564, valueString:0xE592427A0AEce92De3Edee1F18E0157C05861564}, {name:takerAssetAddr, type:address, order:2, indexed:false, value:0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, valueString:0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984}, {name:makerAssetAddr, type:address, order:3, indexed:false, value:0xdAC17F958D2ee523a2206206994597C13D831ec7, valueString:0xdAC17F958D2ee523a2206206994597C13D831ec7}, {name:takerAssetAmount, type:uint256, order:4, indexed:false, value:3349318600000000000000, valueString:3349318600000000000000}, {name:makerAssetAmount, type:uint256, order:5, indexed:false, value:35480453336, valueString:35480453336}, {name:userAddr, type:address, order:6, indexed:false, value:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, valueString:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88}, {name:receiverAddr, type:address, order:7, indexed:false, value:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, valueString:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88}, {name:salt, type:uint256, order:8, indexed:false, value:85887630003356429976251224203095045570230035918583522570052198551885168353218, valueString:85887630003356429976251224203095045570230035918583522570052198551885168353218}, {name:deadline, type:uint256, order:9, indexed:false, value:1708701625, valueString:1708701625}] )

Account State Difference:

  Address   Before After State Difference Code
0x11b815ef...14B7697F6
(Uniswap V3: USDT 3)
0x1d42064F...b5B8Bd801
(Uniswap V3: UNI)
4.223839507575947393 Eth4.223942326875947393 Eth0.0001028193
0x1f9840a8...C4201F984
0x6D9Cc14a...cD12E7903
(Tokenlon: Permanent Storage Proxy)
0xC02aaA39...83C756Cc2
0xdAC17F95...13D831ec7
0xf9699dA6...88D16FA88
35.767421018959148161 Eth
Nonce: 22
35.74355320145809017 Eth
Nonce: 23
0.023867817501057991

Execution Trace

Tokenlon.e47d166c( )
  • UserProxy.toAMM( _payload=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
    • AMMWrapperWithPath.trade( _order=[{name:makerAddr, type:address, order:1, indexed:false, value:0xE592427A0AEce92De3Edee1F18E0157C05861564, valueString:0xE592427A0AEce92De3Edee1F18E0157C05861564}, {name:takerAssetAddr, type:address, order:2, indexed:false, value:0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, valueString:0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984}, {name:makerAssetAddr, type:address, order:3, indexed:false, value:0xdAC17F958D2ee523a2206206994597C13D831ec7, valueString:0xdAC17F958D2ee523a2206206994597C13D831ec7}, {name:takerAssetAmount, type:uint256, order:4, indexed:false, value:3349318600000000000000, valueString:3349318600000000000000}, {name:makerAssetAmount, type:uint256, order:5, indexed:false, value:35480453336, valueString:35480453336}, {name:userAddr, type:address, order:6, indexed:false, value:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, valueString:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88}, {name:receiverAddr, type:address, order:7, indexed:false, value:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, valueString:0xf9699dA649cad0ED4bD9152CaB872F288D16FA88}, {name:salt, type:uint256, order:8, indexed:false, value:85887630003356429976251224203095045570230035918583522570052198551885168353218, valueString:85887630003356429976251224203095045570230035918583522570052198551885168353218}, {name:deadline, type:uint256, order:9, indexed:false, value:1708701625, valueString:1708701625}], _feeFactor=10, _sig=0xED3FAA6AAF00958EE9FD779CBEFA236DBC22E16187010E3BCBD6BE598EC9494D46BAD9DF9DEF665EB96E350CB6989CD0382A3BCD11495A4D5BE8031E6A86DB8C1B000000000000000000000000000000000000000000000000000000000000000002, _makerSpecificData=0x0000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000421F9840A85D5AF5BF1D1762F925BDADDC4201F984000BB8C02AAA39B223FE8D0A0E5C4F27EAD9083C756CC20001F4DAC17F958D2EE523A2206206994597C13D831EC7000000000000000000000000000000000000000000000000000000000000, _path=[0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2, 0xdAC17F958D2ee523a2206206994597C13D831ec7] ) => ( 35831978626 )
      • TransparentUpgradeableProxy.2feeea3a( )
        • PermanentStorage.isRelayerValid( _relayer=0xf9699dA649cad0ED4bD9152CaB872F288D16FA88 ) => ( False )
        • Null: 0x000...001.f9eba511( )
        • TransparentUpgradeableProxy.36ef4251( )
          • PermanentStorage.setAMMTransactionSeen( _transactionHash=14D0BE66B8B46B3CFB62DE44AB372781B8D7501699CB766CEEF6020EC1F98532 )
          • Spender.spendFromUser( _user=0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, _tokenAddr=0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, _amount=3349318600000000000000 )
            • Uni.balanceOf( account=0x4a14347083B80E5216cA31350a2D21702aC3650d ) => ( 792288904427227160551 )
            • AllowanceTarget.executeCall( target=0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984, callData=0x23B872DD000000000000000000000000F9699DA649CAD0ED4BD9152CAB872F288D16FA880000000000000000000000004A14347083B80E5216CA31350A2D21702AC3650D0000000000000000000000000000000000000000000000B59122013FE0A48000 ) => ( resultData=0x0000000000000000000000000000000000000000000000000000000000000001 )
              • Uni.transferFrom( src=0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, dst=0x4a14347083B80E5216cA31350a2D21702aC3650d, rawAmount=3349318600000000000000 ) => ( True )
              • Uni.balanceOf( account=0x4a14347083B80E5216cA31350a2D21702aC3650d ) => ( 4141607504427227160551 )
              • Uni.allowance( account=0x4a14347083B80E5216cA31350a2D21702aC3650d, spender=0xE592427A0AEce92De3Edee1F18E0157C05861564 ) => ( 0 )
              • Uni.approve( spender=0xE592427A0AEce92De3Edee1F18E0157C05861564, rawAmount=115792089237316195423570985008687907853269984665640564039457584007913129639935 ) => ( True )
              • SwapRouter.exactInput( params=[{name:path, type:bytes, order:1, indexed:false, value:0x1F9840A85D5AF5BF1D1762F925BDADDC4201F984000BB8C02AAA39B223FE8D0A0E5C4F27EAD9083C756CC20001F4DAC17F958D2EE523A2206206994597C13D831EC7, valueString:0x1F9840A85D5AF5BF1D1762F925BDADDC4201F984000BB8C02AAA39B223FE8D0A0E5C4F27EAD9083C756CC20001F4DAC17F958D2EE523A2206206994597C13D831EC7}, {name:recipient, type:address, order:2, indexed:false, value:0x4a14347083B80E5216cA31350a2D21702aC3650d, valueString:0x4a14347083B80E5216cA31350a2D21702aC3650d}, {name:deadline, type:uint256, order:3, indexed:false, value:1708701625, valueString:1708701625}, {name:amountIn, type:uint256, order:4, indexed:false, value:3349318600000000000000, valueString:3349318600000000000000}, {name:amountOutMinimum, type:uint256, order:5, indexed:false, value:35480453336, valueString:35480453336}] ) => ( amountOut=35867846473 )
                • UniswapV3Pool.swap( recipient=0xE592427A0AEce92De3Edee1F18E0157C05861564, zeroForOne=True, amountSpecified=3349318600000000000000, sqrtPriceLimitX96=4295128740, data=0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000400000000000000000000000004A14347083B80E5216CA31350A2D21702AC3650D000000000000000000000000000000000000000000000000000000000000002B1F9840A85D5AF5BF1D1762F925BDADDC4201F984000BB8C02AAA39B223FE8D0A0E5C4F27EAD9083C756CC2000000000000000000000000000000000000000000 ) => ( amount0=3349318600000000000000, amount1=-12206417337253230110 )
                  • WETH9.transfer( dst=0xE592427A0AEce92De3Edee1F18E0157C05861564, wad=12206417337253230110 ) => ( True )
                  • Uni.balanceOf( account=0x1d42064Fc4Beb5F8aAF85F4617AE8b3b5B8Bd801 ) => ( 1168512388991381632102955 )
                  • SwapRouter.uniswapV3SwapCallback( amount0Delta=3349318600000000000000, amount1Delta=-12206417337253230110, _data=0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000400000000000000000000000004A14347083B80E5216CA31350A2D21702AC3650D000000000000000000000000000000000000000000000000000000000000002B1F9840A85D5AF5BF1D1762F925BDADDC4201F984000BB8C02AAA39B223FE8D0A0E5C4F27EAD9083C756CC2000000000000000000000000000000000000000000 )
                    • Uni.transferFrom( src=0x4a14347083B80E5216cA31350a2D21702aC3650d, dst=0x1d42064Fc4Beb5F8aAF85F4617AE8b3b5B8Bd801, rawAmount=3349318600000000000000 ) => ( True )
                    • Uni.balanceOf( account=0x1d42064Fc4Beb5F8aAF85F4617AE8b3b5B8Bd801 ) => ( 1171861707591381632102955 )
                    • UniswapV3Pool.swap( recipient=0x4a14347083B80E5216cA31350a2D21702aC3650d, zeroForOne=True, amountSpecified=12206417337253230110, sqrtPriceLimitX96=4295128740, data=0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000040000000000000000000000000E592427A0AECE92DE3EDEE1F18E0157C05861564000000000000000000000000000000000000000000000000000000000000002BC02AAA39B223FE8D0A0E5C4F27EAD9083C756CC20001F4DAC17F958D2EE523A2206206994597C13D831EC7000000000000000000000000000000000000000000 ) => ( amount0=12206417337253230110, amount1=-35867846473 )
                      • TetherToken.transfer( _to=0x4a14347083B80E5216cA31350a2D21702aC3650d, _value=35867846473 )
                      • WETH9.balanceOf( 0x11b815efB8f581194ae79006d24E0d814B7697F6 ) => ( 3296982170397927570680 )
                      • SwapRouter.uniswapV3SwapCallback( amount0Delta=12206417337253230110, amount1Delta=-35867846473, _data=0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000040000000000000000000000000E592427A0AECE92DE3EDEE1F18E0157C05861564000000000000000000000000000000000000000000000000000000000000002BC02AAA39B223FE8D0A0E5C4F27EAD9083C756CC20001F4DAC17F958D2EE523A2206206994597C13D831EC7000000000000000000000000000000000000000000 )
                        • WETH9.transfer( dst=0x11b815efB8f581194ae79006d24E0d814B7697F6, wad=12206417337253230110 ) => ( True )
                        • WETH9.balanceOf( 0x11b815efB8f581194ae79006d24E0d814B7697F6 ) => ( 3309188587735180800790 )
                        • Uni.approve( spender=0xE592427A0AEce92De3Edee1F18E0157C05861564, rawAmount=0 ) => ( True )
                        • TetherToken.transfer( _to=0xf9699dA649cad0ED4bD9152CaB872F288D16FA88, _value=35831978626 )
                          File 1 of 13: Tokenlon
                          // SPDX-License-Identifier: MIT
                          // File: @openzeppelin/contracts/utils/Address.sol
                          pragma solidity ^0.6.2;
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev Returns true if `account` is a contract.
                               *
                               * [IMPORTANT]
                               * ====
                               * It is unsafe to assume that an address for which this function returns
                               * false is an externally-owned account (EOA) and not a contract.
                               *
                               * Among others, `isContract` will return false for the following
                               * types of addresses:
                               *
                               *  - an externally-owned account
                               *  - a contract in construction
                               *  - an address where a contract will be created
                               *  - an address where a contract lived, but was destroyed
                               * ====
                               */
                              function isContract(address account) internal view returns (bool) {
                                  // This method relies in extcodesize, which returns 0 for contracts in
                                  // construction, since the code is only stored at the end of the
                                  // constructor execution.
                                  uint256 size;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { size := extcodesize(account) }
                                  return size > 0;
                              }
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  require(address(this).balance >= amount, "Address: insufficient balance");
                                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                  (bool success, ) = recipient.call{ value: amount }("");
                                  require(success, "Address: unable to send value, recipient may have reverted");
                              }
                              /**
                               * @dev Performs a Solidity function call using a low level `call`. A
                               * plain`call` is an unsafe replacement for a function call: use this
                               * function instead.
                               *
                               * If `target` reverts with a revert reason, it is bubbled up by this
                               * function (like regular Solidity function calls).
                               *
                               * Returns the raw returned data. To convert to the expected return value,
                               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                               *
                               * Requirements:
                               *
                               * - `target` must be a contract.
                               * - calling `target` with `data` must not revert.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                return functionCall(target, data, "Address: low-level call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                               * `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  return _functionCallWithValue(target, data, 0, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but also transferring `value` wei to `target`.
                               *
                               * Requirements:
                               *
                               * - the calling contract must have an ETH balance of at least `value`.
                               * - the called Solidity function must be `payable`.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                               * with `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                  require(address(this).balance >= value, "Address: insufficient balance for call");
                                  return _functionCallWithValue(target, data, value, errorMessage);
                              }
                              function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
                                  require(isContract(target), "Address: call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
                                  if (success) {
                                      return returndata;
                                  } else {
                                      // Look for revert reason and bubble it up if present
                                      if (returndata.length > 0) {
                                          // The easiest way to bubble the revert reason is using memory via assembly
                                          // solhint-disable-next-line no-inline-assembly
                                          assembly {
                                              let returndata_size := mload(returndata)
                                              revert(add(32, returndata), returndata_size)
                                          }
                                      } else {
                                          revert(errorMessage);
                                      }
                                  }
                              }
                          }
                          // File: contracts/upgrade_proxy/Proxy.sol
                          pragma solidity ^0.6.0;
                          /**
                           * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                           * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                           * be specified by overriding the virtual {_implementation} function.
                           * 
                           * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                           * different contract through the {_delegate} function.
                           * 
                           * The success and return data of the delegated call will be returned back to the caller of the proxy.
                           */
                          abstract contract Proxy {
                              /**
                               * @dev Delegates the current call to `implementation`.
                               * 
                               * This function does not return to its internall call site, it will return directly to the external caller.
                               */
                              function _delegate(address implementation) internal {
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      // Copy msg.data. We take full control of memory in this inline assembly
                                      // block because it will not return to Solidity code. We overwrite the
                                      // Solidity scratch pad at memory position 0.
                                      calldatacopy(0, 0, calldatasize())
                                      // Call the implementation.
                                      // out and outsize are 0 because we don't know the size yet.
                                      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                      // Copy the returned data.
                                      returndatacopy(0, 0, returndatasize())
                                      switch result
                                      // delegatecall returns 0 on error.
                                      case 0 { revert(0, returndatasize()) }
                                      default { return(0, returndatasize()) }
                                  }
                              }
                              /**
                               * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                               * and {_fallback} should delegate.
                               */
                              function _implementation() internal virtual view returns (address);
                              /**
                               * @dev Delegates the current call to the address returned by `_implementation()`.
                               * 
                               * This function does not return to its internall call site, it will return directly to the external caller.
                               */
                              function _fallback() internal {
                                  _beforeFallback();
                                  _delegate(_implementation());
                              }
                              /**
                               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                               * function in the contract matches the call data.
                               */
                              fallback () payable external {
                                  _fallback();
                              }
                              /**
                               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                               * is empty.
                               */
                              receive () payable external {
                                  _fallback();
                              }
                              /**
                               * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                               * call, or as part of the Solidity `fallback` or `receive` functions.
                               * 
                               * If overriden should call `super._beforeFallback()`.
                               */
                              function _beforeFallback() internal virtual {
                              }
                          }
                          // File: contracts/upgrade_proxy/UpgradeableProxy.sol
                          pragma solidity ^0.6.0;
                          /**
                           * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                           * implementation address that can be changed. This address is stored in storage in the location specified by
                           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                           * implementation behind the proxy.
                           * 
                           * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see
                           * {TransparentUpgradeableProxy}.
                           */
                          contract UpgradeableProxy is Proxy {
                              /**
                               * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                               * 
                               * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                               * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                               */
                              constructor(address _logic, bytes memory _data) public payable {
                                  assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                  _setImplementation(_logic);
                                  if(_data.length > 0) {
                                      // solhint-disable-next-line avoid-low-level-calls
                                      (bool success,) = _logic.delegatecall(_data);
                                      require(success);
                                  }
                              }
                              /**
                               * @dev Emitted when the implementation is upgraded.
                               */
                              event Upgraded(address indexed implementation);
                              /**
                               * @dev Storage slot with the address of the current implementation.
                               * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                               * validated in the constructor.
                               */
                              bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                              /**
                               * @dev Returns the current implementation address.
                               */
                              function _implementation() internal override view returns (address impl) {
                                  bytes32 slot = _IMPLEMENTATION_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      impl := sload(slot)
                                  }
                              }
                              /**
                               * @dev Upgrades the proxy to a new implementation.
                               * 
                               * Emits an {Upgraded} event.
                               */
                              function _upgradeTo(address newImplementation) internal {
                                  _setImplementation(newImplementation);
                                  emit Upgraded(newImplementation);
                              }
                              /**
                               * @dev Stores a new address in the EIP1967 implementation slot.
                               */
                              function _setImplementation(address newImplementation) private {
                                  require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");
                                  bytes32 slot = _IMPLEMENTATION_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      sstore(slot, newImplementation)
                                  }
                              }
                          }
                          // File: contracts/upgrade_proxy/TransparentUpgradeableProxy.sol
                          pragma solidity ^0.6.0;
                          /**
                           * @dev This contract implements a proxy that is upgradeable by an admin.
                           * 
                           * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                           * clashing], which can potentially be used in an attack, this contract uses the
                           * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                           * things that go hand in hand:
                           * 
                           * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                           * that call matches one of the admin functions exposed by the proxy itself.
                           * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                           * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                           * "admin cannot fallback to proxy target".
                           * 
                           * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                           * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                           * to sudden errors when trying to call a function from the proxy implementation.
                           * 
                           * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                           * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
                           */
                          contract TransparentUpgradeableProxy is UpgradeableProxy {
                              /**
                               * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                               * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
                               */
                              constructor(address _logic, address _admin, bytes memory _data) public payable UpgradeableProxy(_logic, _data) {
                                  assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                                  _setAdmin(_admin);
                              }
                              /**
                               * @dev Emitted when the admin account has changed.
                               */
                              event AdminChanged(address previousAdmin, address newAdmin);
                              /**
                               * @dev Storage slot with the admin of the contract.
                               * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                               * validated in the constructor.
                               */
                              bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                              /**
                               * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                               */
                              modifier ifAdmin() {
                                  if (msg.sender == _admin()) {
                                      _;
                                  } else {
                                      _fallback();
                                  }
                              }
                              /**
                               * @dev Returns the current admin.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
                               * 
                               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                               * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                               */
                              function admin() external ifAdmin returns (address) {
                                  return _admin();
                              }
                              /**
                               * @dev Returns the current implementation.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
                               * 
                               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                               * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                               */
                              function implementation() external ifAdmin returns (address) {
                                  return _implementation();
                              }
                              /**
                               * @dev Changes the admin of the proxy.
                               * 
                               * Emits an {AdminChanged} event.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
                               */
                              function changeAdmin(address newAdmin) external ifAdmin {
                                  require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
                                  emit AdminChanged(_admin(), newAdmin);
                                  _setAdmin(newAdmin);
                              }
                              /**
                               * @dev Upgrade the implementation of the proxy.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
                               */
                              function upgradeTo(address newImplementation) external ifAdmin {
                                  _upgradeTo(newImplementation);
                              }
                              /**
                               * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                               * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                               * proxied contract.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
                               */
                              function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                                  _upgradeTo(newImplementation);
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success,) = newImplementation.delegatecall(data);
                                  require(success);
                              }
                              /**
                               * @dev Returns the current admin.
                               */
                              function _admin() internal view returns (address adm) {
                                  bytes32 slot = _ADMIN_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      adm := sload(slot)
                                  }
                              }
                              /**
                               * @dev Stores a new address in the EIP1967 admin slot.
                               */
                              function _setAdmin(address newAdmin) private {
                                  bytes32 slot = _ADMIN_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      sstore(slot, newAdmin)
                                  }
                              }
                              /**
                               * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
                               */
                              function _beforeFallback() internal override virtual {
                                  require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                  super._beforeFallback();
                              }
                          }
                          // File: contracts/Tokenlon.sol
                          pragma solidity ^0.6.0;
                          contract Tokenlon is TransparentUpgradeableProxy {
                              constructor(address _logic, address _admin, bytes memory _data) public payable TransparentUpgradeableProxy(_logic, _admin, _data) {}
                          }

                          File 2 of 13: AMMWrapperWithPath
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.6.5;
                          import "@openzeppelin/contracts/utils/Address.sol";
                          import "./interfaces/IAllowanceTarget.sol";
                          /**
                           * @dev AllowanceTarget contract
                           */
                          contract AllowanceTarget is IAllowanceTarget {
                              using Address for address;
                              uint256 constant private TIME_LOCK_DURATION = 1 days;
                              address public spender;
                              address public newSpender;
                              uint256 public timelockExpirationTime;
                              modifier onlySpender() {
                                  require(spender == msg.sender, "AllowanceTarget: not the spender");
                                  _;
                              }
                              constructor(address _spender) public {
                                  require(_spender != address(0), "AllowanceTarget: _spender should not be 0");
                                  // Set spender
                                  spender = _spender;
                              }
                              function setSpenderWithTimelock(address _newSpender) override external onlySpender {
                                  require(_newSpender.isContract(), "AllowanceTarget: new spender not a contract");
                                  require(newSpender == address(0) && timelockExpirationTime == 0, "AllowanceTarget: SetSpender in progress");
                                  timelockExpirationTime = now + TIME_LOCK_DURATION;
                                  newSpender = _newSpender;
                              }
                              function completeSetSpender() override external {
                                  require(timelockExpirationTime != 0, "AllowanceTarget: no pending SetSpender");
                                  require(now >= timelockExpirationTime, "AllowanceTarget: time lock not expired yet");
                                  // Set new spender
                                  spender = newSpender;
                                  // Reset
                                  timelockExpirationTime = 0;
                                  newSpender = address(0);
                              }
                              function teardown() override external onlySpender {
                                  selfdestruct(payable(spender));
                              }
                              /// @dev Execute an arbitrary call. Only an authority can call this.
                              /// @param target The call target.
                              /// @param callData The call data.
                              /// @return resultData The data returned by the call.
                              function executeCall(
                                  address payable target,
                                  bytes calldata callData
                              )
                                  override
                                  external
                                  onlySpender
                                  returns (bytes memory resultData)
                              {
                                  bool success;
                                  (success, resultData) = target.call(callData);
                                  if (!success) {
                                      // Get the error message returned
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.2 <0.8.0;
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev Returns true if `account` is a contract.
                               *
                               * [IMPORTANT]
                               * ====
                               * It is unsafe to assume that an address for which this function returns
                               * false is an externally-owned account (EOA) and not a contract.
                               *
                               * Among others, `isContract` will return false for the following
                               * types of addresses:
                               *
                               *  - an externally-owned account
                               *  - a contract in construction
                               *  - an address where a contract will be created
                               *  - an address where a contract lived, but was destroyed
                               * ====
                               */
                              function isContract(address account) internal view returns (bool) {
                                  // This method relies on extcodesize, which returns 0 for contracts in
                                  // construction, since the code is only stored at the end of the
                                  // constructor execution.
                                  uint256 size;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { size := extcodesize(account) }
                                  return size > 0;
                              }
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  require(address(this).balance >= amount, "Address: insufficient balance");
                                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                  (bool success, ) = recipient.call{ value: amount }("");
                                  require(success, "Address: unable to send value, recipient may have reverted");
                              }
                              /**
                               * @dev Performs a Solidity function call using a low level `call`. A
                               * plain`call` is an unsafe replacement for a function call: use this
                               * function instead.
                               *
                               * If `target` reverts with a revert reason, it is bubbled up by this
                               * function (like regular Solidity function calls).
                               *
                               * Returns the raw returned data. To convert to the expected return value,
                               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                               *
                               * Requirements:
                               *
                               * - `target` must be a contract.
                               * - calling `target` with `data` must not revert.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                return functionCall(target, data, "Address: low-level call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                               * `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, 0, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but also transferring `value` wei to `target`.
                               *
                               * Requirements:
                               *
                               * - the calling contract must have an ETH balance of at least `value`.
                               * - the called Solidity function must be `payable`.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                               * with `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                  require(address(this).balance >= value, "Address: insufficient balance for call");
                                  require(isContract(target), "Address: call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.call{ value: value }(data);
                                  return _verifyCallResult(success, returndata, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but performing a static call.
                               *
                               * _Available since v3.3._
                               */
                              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                  return functionStaticCall(target, data, "Address: low-level static call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                               * but performing a static call.
                               *
                               * _Available since v3.3._
                               */
                              function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                                  require(isContract(target), "Address: static call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.staticcall(data);
                                  return _verifyCallResult(success, returndata, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but performing a delegate call.
                               *
                               * _Available since v3.4._
                               */
                              function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                  return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                               * but performing a delegate call.
                               *
                               * _Available since v3.4._
                               */
                              function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  require(isContract(target), "Address: delegate call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.delegatecall(data);
                                  return _verifyCallResult(success, returndata, errorMessage);
                              }
                              function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                                  if (success) {
                                      return returndata;
                                  } else {
                                      // Look for revert reason and bubble it up if present
                                      if (returndata.length > 0) {
                                          // The easiest way to bubble the revert reason is using memory via assembly
                                          // solhint-disable-next-line no-inline-assembly
                                          assembly {
                                              let returndata_size := mload(returndata)
                                              revert(add(32, returndata), returndata_size)
                                          }
                                      } else {
                                          revert(errorMessage);
                                      }
                                  }
                              }
                          }
                          pragma solidity ^0.6.0;
                          interface IAllowanceTarget {
                              function setSpenderWithTimelock(address _newSpender) external;
                              function completeSetSpender() external;
                              function executeCall(address payable _target, bytes calldata _callData) external returns (bytes memory resultData);
                              function teardown() external;
                          }// SPDX-License-Identifier: MIT
                          pragma solidity ^0.6.5;
                          import "@openzeppelin/contracts/math/SafeMath.sol";
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "./interfaces/IAllowanceTarget.sol";
                          /**
                           * @dev Spender contract
                           */
                          contract Spender {
                              using SafeMath for uint256;
                              // Constants do not have storage slot.
                              address private constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant ZERO_ADDRESS = address(0);
                              uint256 constant private TIME_LOCK_DURATION = 1 days;
                              // Below are the variables which consume storage slots.
                              address public operator;
                              address public pendingOperator;
                              address public allowanceTarget;
                              mapping(address => bool) private authorized;
                              mapping(address => bool) private tokenBlacklist;
                              uint256 public numPendingAuthorized;
                              mapping(uint256 => address) public pendingAuthorized;
                              uint256 public timelockExpirationTime;
                              uint256 public contractDeployedTime;
                              bool public timelockActivated;
                              mapping(address => bool) public consumeGasERC20Tokens;
                              // System events
                              event TimeLockActivated(uint256 activatedTimeStamp);
                              // Operator events
                              event TransferOwnership(address newOperator);
                              event SetAllowanceTarget(address allowanceTarget);
                              event SetNewSpender(address newSpender);
                              event SetConsumeGasERC20Token(address token);
                              event TearDownAllowanceTarget(uint256 tearDownTimeStamp);
                              event BlackListToken(address token, bool isBlacklisted);
                              event AuthorizeSpender(address spender, bool isAuthorized);
                              /************************************************************
                              *          Access control and ownership management          *
                              *************************************************************/
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "Spender: not the operator");
                                  _;
                              }
                              modifier onlyAuthorized() {
                                  require(authorized[msg.sender], "Spender: not authorized");
                                  _;
                              }
                              function setNewOperator(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "Spender: operator can not be zero address");
                                  pendingOperator = _newOperator;
                              }
                              function acceptAsOperator() external {
                                  require(pendingOperator == msg.sender, "Spender: only nominated one can accept as new operator");
                                  operator = pendingOperator;
                                  pendingOperator = address(0);
                                  emit TransferOwnership(pendingOperator);
                              }
                              /************************************************************
                              *                    Timelock management                    *
                              *************************************************************/
                              /// @dev Everyone can activate timelock after the contract has been deployed for more than 1 day.
                              function activateTimelock() external {
                                  bool canActivate = block.timestamp.sub(contractDeployedTime) > 1 days;
                                  require(canActivate && ! timelockActivated, "Spender: can not activate timelock yet or has been activated");
                                  timelockActivated = true;
                                  emit TimeLockActivated(block.timestamp);
                              }
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              constructor(address _operator, address[] memory _consumeGasERC20Tokens) public {
                                  require(_operator != address(0), "Spender: _operator should not be 0");
                                  // Set operator
                                  operator = _operator;
                                  timelockActivated = false;
                                  contractDeployedTime = block.timestamp;
                                  for (uint256 i = 0; i < _consumeGasERC20Tokens.length; i++) {
                                      consumeGasERC20Tokens[_consumeGasERC20Tokens[i]] = true;
                                  }
                              }
                              function setAllowanceTarget(address _allowanceTarget) external onlyOperator {
                                  require(allowanceTarget == address(0), "Spender: can not reset allowance target");
                                  // Set allowanceTarget
                                  allowanceTarget = _allowanceTarget;
                                  emit SetAllowanceTarget(_allowanceTarget);
                              }
                              /************************************************************
                              *          AllowanceTarget interaction functions            *
                              *************************************************************/
                              function setNewSpender(address _newSpender) external onlyOperator {
                                  IAllowanceTarget(allowanceTarget).setSpenderWithTimelock(_newSpender);
                                  emit SetNewSpender(_newSpender);
                              }
                              function teardownAllowanceTarget() external onlyOperator {
                                  IAllowanceTarget(allowanceTarget).teardown();
                                  emit TearDownAllowanceTarget(block.timestamp);
                              }
                              /************************************************************
                              *           Whitelist and blacklist functions               *
                              *************************************************************/
                              function isBlacklisted(address _tokenAddr) external view returns (bool) {
                                  return tokenBlacklist[_tokenAddr];
                              }
                              function blacklist(address[] calldata _tokenAddrs, bool[] calldata _isBlacklisted) external onlyOperator {
                                  require(_tokenAddrs.length == _isBlacklisted.length, "Spender: length mismatch");
                                  for (uint256 i = 0; i < _tokenAddrs.length; i++) {
                                      tokenBlacklist[_tokenAddrs[i]] = _isBlacklisted[i];
                                      emit BlackListToken(_tokenAddrs[i], _isBlacklisted[i]);
                                  }
                              }
                              
                              function isAuthorized(address _caller) external view returns (bool) {
                                  return authorized[_caller];
                              }
                              function authorize(address[] calldata _pendingAuthorized) external onlyOperator {
                                  require(_pendingAuthorized.length > 0, "Spender: authorize list is empty");
                                  require(numPendingAuthorized == 0 && timelockExpirationTime == 0, "Spender: an authorize current in progress");
                                  if (timelockActivated) {
                                      numPendingAuthorized = _pendingAuthorized.length;
                                      for (uint256 i = 0; i < _pendingAuthorized.length; i++) {
                                          require(_pendingAuthorized[i] != address(0), "Spender: can not authorize zero address");
                                          pendingAuthorized[i] = _pendingAuthorized[i];
                                      }
                                      timelockExpirationTime = now + TIME_LOCK_DURATION;
                                  } else {
                                      for (uint256 i = 0; i < _pendingAuthorized.length; i++) {
                                          require(_pendingAuthorized[i] != address(0), "Spender: can not authorize zero address");
                                          authorized[_pendingAuthorized[i]] = true;
                                          emit AuthorizeSpender(_pendingAuthorized[i], true);
                                      }
                                  }
                              }
                              function completeAuthorize() external {
                                  require(timelockExpirationTime != 0, "Spender: no pending authorize");
                                  require(now >= timelockExpirationTime, "Spender: time lock not expired yet");
                                  for (uint256 i = 0; i < numPendingAuthorized; i++) {
                                      authorized[pendingAuthorized[i]] = true;
                                      emit AuthorizeSpender(pendingAuthorized[i], true);
                                      delete pendingAuthorized[i];
                                  }
                                  timelockExpirationTime = 0;
                                  numPendingAuthorized = 0;
                              }
                              function deauthorize(address[] calldata _deauthorized) external onlyOperator {
                                  for (uint256 i = 0; i < _deauthorized.length; i++) {
                                      authorized[_deauthorized[i]] = false;
                                      emit AuthorizeSpender(_deauthorized[i], false);
                                  }
                              }
                              function setConsumeGasERC20Tokens(address[] memory _consumeGasERC20Tokens) external onlyOperator {
                                  for (uint256 i = 0; i < _consumeGasERC20Tokens.length; i++) {
                                      consumeGasERC20Tokens[_consumeGasERC20Tokens[i]] = true;
                                      emit SetConsumeGasERC20Token(_consumeGasERC20Tokens[i]);
                                  }
                              }
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              /// @dev Spend tokens on user's behalf. Only an authority can call this.
                              /// @param _user The user to spend token from.
                              /// @param _tokenAddr The address of the token.
                              /// @param _amount Amount to spend.
                              function spendFromUser(address _user, address _tokenAddr, uint256 _amount) external onlyAuthorized {
                                  require(! tokenBlacklist[_tokenAddr], "Spender: token is blacklisted");
                                  // Fix gas stipend for non standard ERC20 transfer in case token contract's SafeMath violation is triggered
                                  // and all gas are consumed.
                                  uint256 gasStipend;
                                  if(consumeGasERC20Tokens[_tokenAddr]) gasStipend = 80000;
                                  else gasStipend = gasleft();
                                  if (_tokenAddr != ETH_ADDRESS && _tokenAddr != ZERO_ADDRESS) {
                                      uint256 balanceBefore = IERC20(_tokenAddr).balanceOf(msg.sender);
                                      (bool callSucceed, bytes memory returndata) = address(allowanceTarget).call{gas: gasStipend}(
                                          abi.encodeWithSelector(
                                              IAllowanceTarget.executeCall.selector,
                                              _tokenAddr,
                                              abi.encodeWithSelector(
                                                  IERC20.transferFrom.selector,
                                                  _user,
                                                  msg.sender,
                                                  _amount
                                              )
                                          )
                                      );
                                      require(callSucceed, "Spender: ERC20 transferFrom failed");
                                      bytes memory decodedReturnData = abi.decode(returndata, (bytes));
                                      if (decodedReturnData.length > 0) { // Return data is optional
                                          // Tokens like ZRX returns false on failed transfer
                                          require(abi.decode(decodedReturnData, (bool)), "Spender: ERC20 transferFrom failed");
                                      }
                                      // Check balance
                                      uint256 balanceAfter = IERC20(_tokenAddr).balanceOf(msg.sender);
                                      require(balanceAfter.sub(balanceBefore) == _amount, "Spender: ERC20 transferFrom amount mismatch");
                                  }
                              }
                              /// @dev Spend tokens on user's behalf. Only an authority can call this.
                              /// @param _user The user to spend token from.
                              /// @param _tokenAddr The address of the token.
                              /// @param _receiver The receiver of the token.
                              /// @param _amount Amount to spend.
                              function spendFromUserTo(address _user, address _tokenAddr, address _receiver, uint256 _amount) external onlyAuthorized {
                                  require(! tokenBlacklist[_tokenAddr], "Spender: token is blacklisted");
                                  // Fix gas stipend for non standard ERC20 transfer in case token contract's SafeMath violation is triggered
                                  // and all gas are consumed.
                                  uint256 gasStipend;
                                  if(consumeGasERC20Tokens[_tokenAddr]) gasStipend = 80000;
                                  else gasStipend = gasleft();
                                  if (_tokenAddr != ETH_ADDRESS && _tokenAddr != ZERO_ADDRESS) {
                                      uint256 balanceBefore = IERC20(_tokenAddr).balanceOf(msg.sender);
                                      (bool callSucceed, bytes memory returndata) = address(allowanceTarget).call{gas: gasStipend}(
                                          abi.encodeWithSelector(
                                              IAllowanceTarget.executeCall.selector,
                                              _tokenAddr,
                                              abi.encodeWithSelector(
                                                  IERC20.transferFrom.selector,
                                                  _user,
                                                  _receiver,
                                                  _amount
                                              )
                                          )
                                      );
                                      require(callSucceed, "Spender: ERC20 transferFrom failed");
                                      bytes memory decodedReturnData = abi.decode(returndata, (bytes));
                                      if (decodedReturnData.length > 0) { // Return data is optional
                                          // Tokens like ZRX returns false on failed transfer
                                          require(abi.decode(decodedReturnData, (bool)), "Spender: ERC20 transferFrom failed");
                                      }
                                      // Check balance
                                      uint256 balanceAfter = IERC20(_tokenAddr).balanceOf(msg.sender);
                                      require(balanceAfter.sub(balanceBefore) == _amount, "Spender: ERC20 transferFrom amount mismatch");
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev Wrappers over Solidity's arithmetic operations with added overflow
                           * checks.
                           *
                           * Arithmetic operations in Solidity wrap on overflow. This can easily result
                           * in bugs, because programmers usually assume that an overflow raises an
                           * error, which is the standard behavior in high level programming languages.
                           * `SafeMath` restores this intuition by reverting the transaction when an
                           * operation overflows.
                           *
                           * Using this library instead of the unchecked operations eliminates an entire
                           * class of bugs, so it's recommended to use it always.
                           */
                          library SafeMath {
                              /**
                               * @dev Returns the addition of two unsigned integers, with an overflow flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  uint256 c = a + b;
                                  if (c < a) return (false, 0);
                                  return (true, c);
                              }
                              /**
                               * @dev Returns the substraction of two unsigned integers, with an overflow flag.
                               *
                               * _Available since v3.4._
                               */
                              function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  if (b > a) return (false, 0);
                                  return (true, a - b);
                              }
                              /**
                               * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                                  if (a == 0) return (true, 0);
                                  uint256 c = a * b;
                                  if (c / a != b) return (false, 0);
                                  return (true, c);
                              }
                              /**
                               * @dev Returns the division of two unsigned integers, with a division by zero flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  if (b == 0) return (false, 0);
                                  return (true, a / b);
                              }
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
                               *
                               * _Available since v3.4._
                               */
                              function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                                  if (b == 0) return (false, 0);
                                  return (true, a % b);
                              }
                              /**
                               * @dev Returns the addition of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `+` operator.
                               *
                               * Requirements:
                               *
                               * - Addition cannot overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a, "SafeMath: addition overflow");
                                  return c;
                              }
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting on
                               * overflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               *
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b <= a, "SafeMath: subtraction overflow");
                                  return a - b;
                              }
                              /**
                               * @dev Returns the multiplication of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `*` operator.
                               *
                               * Requirements:
                               *
                               * - Multiplication cannot overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  if (a == 0) return 0;
                                  uint256 c = a * b;
                                  require(c / a == b, "SafeMath: multiplication overflow");
                                  return c;
                              }
                              /**
                               * @dev Returns the integer division of two unsigned integers, reverting on
                               * division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b > 0, "SafeMath: division by zero");
                                  return a / b;
                              }
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * reverting when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  require(b > 0, "SafeMath: modulo by zero");
                                  return a % b;
                              }
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                               * overflow (when the result is negative).
                               *
                               * CAUTION: This function is deprecated because it requires allocating memory for the error
                               * message unnecessarily. For custom revert reasons use {trySub}.
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               *
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b <= a, errorMessage);
                                  return a - b;
                              }
                              /**
                               * @dev Returns the integer division of two unsigned integers, reverting with custom message on
                               * division by zero. The result is rounded towards zero.
                               *
                               * CAUTION: This function is deprecated because it requires allocating memory for the error
                               * message unnecessarily. For custom revert reasons use {tryDiv}.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b > 0, errorMessage);
                                  return a / b;
                              }
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * reverting with custom message when dividing by zero.
                               *
                               * CAUTION: This function is deprecated because it requires allocating memory for the error
                               * message unnecessarily. For custom revert reasons use {tryMod}.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b > 0, errorMessage);
                                  return a % b;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev Interface of the ERC20 standard as defined in the EIP.
                           */
                          interface IERC20 {
                              /**
                               * @dev Returns the amount of tokens in existence.
                               */
                              function totalSupply() external view returns (uint256);
                              /**
                               * @dev Returns the amount of tokens owned by `account`.
                               */
                              function balanceOf(address account) external view returns (uint256);
                              /**
                               * @dev Moves `amount` tokens from the caller's account to `recipient`.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transfer(address recipient, uint256 amount) external returns (bool);
                              /**
                               * @dev Returns the remaining number of tokens that `spender` will be
                               * allowed to spend on behalf of `owner` through {transferFrom}. This is
                               * zero by default.
                               *
                               * This value changes when {approve} or {transferFrom} are called.
                               */
                              function allowance(address owner, address spender) external view returns (uint256);
                              /**
                               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * IMPORTANT: Beware that changing an allowance with this method brings the risk
                               * that someone may use both the old and the new allowance by unfortunate
                               * transaction ordering. One possible solution to mitigate this race
                               * condition is to first reduce the spender's allowance to 0 and set the
                               * desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               *
                               * Emits an {Approval} event.
                               */
                              function approve(address spender, uint256 amount) external returns (bool);
                              /**
                               * @dev Moves `amount` tokens from `sender` to `recipient` using the
                               * allowance mechanism. `amount` is then deducted from the caller's
                               * allowance.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                              /**
                               * @dev Emitted when `value` tokens are moved from one account (`from`) to
                               * another (`to`).
                               *
                               * Note that `value` may be zero.
                               */
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              /**
                               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                               * a call to {approve}. `value` is the new allowance.
                               */
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.6.5;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "../interfaces/IAMM.sol";
                          contract UserProxyStub {
                              using SafeERC20 for IERC20;
                              // Constants do not have storage slot.
                              uint256 private constant MAX_UINT = 2**256 - 1;
                              address private constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant ZERO_ADDRESS = address(0);
                              /**
                               * @dev Below are the variables which consume storage slots.
                               */
                              address public operator;
                              address public weth;
                              address public ammWrapperAddr;
                              address public pmmAddr;
                              address public rfqAddr;
                              receive() external payable {
                              }
                              /**
                               * @dev Access control and ownership management.
                               */
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "UserProxyStub: not the operator");
                                  _;
                              }
                              /* End of access control and ownership management */
                              /**
                               * @dev Replacing constructor and initialize the contract. This function should only be called once.
                               */
                              constructor(address _weth) public {
                                  operator = msg.sender;
                                  weth = _weth;
                              }
                              function upgradePMM(address _pmmAddr) external onlyOperator {
                                  pmmAddr = _pmmAddr;
                              }
                              function upgradeAMMWrapper(address _ammWrapperAddr) external onlyOperator {
                                  ammWrapperAddr = _ammWrapperAddr;
                              }
                              function upgradeRFQ(address _rfqAddr) external onlyOperator {
                                  rfqAddr = _rfqAddr;
                              }
                              function toAMM(bytes calldata _payload) external payable {
                                  (bool callSucceed,) = ammWrapperAddr.call{value: msg.value}(_payload);
                                  if (callSucceed == false) {
                                      // Get the error message returned
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                              function toPMM(bytes calldata _payload) external payable {
                                  (bool callSucceed,) = pmmAddr.call{value: msg.value}(_payload);
                                  if (callSucceed == false) {
                                      // Get the error message returned
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                              function toRFQ(bytes calldata _payload) external payable {
                                  (bool callSucceed,) = rfqAddr.call{value: msg.value}(_payload);
                                  if (callSucceed == false) {
                                      // Get the error message returned
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          import "./IERC20.sol";
                          import "../../math/SafeMath.sol";
                          import "../../utils/Address.sol";
                          /**
                           * @title SafeERC20
                           * @dev Wrappers around ERC20 operations that throw on failure (when the token
                           * contract returns false). Tokens that return no value (and instead revert or
                           * throw on failure) are also supported, non-reverting calls are assumed to be
                           * successful.
                           * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                           * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                           */
                          library SafeERC20 {
                              using SafeMath for uint256;
                              using Address for address;
                              function safeTransfer(IERC20 token, address to, uint256 value) internal {
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                              }
                              function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                              }
                              /**
                               * @dev Deprecated. This function has issues similar to the ones found in
                               * {IERC20-approve}, and its usage is discouraged.
                               *
                               * Whenever possible, use {safeIncreaseAllowance} and
                               * {safeDecreaseAllowance} instead.
                               */
                              function safeApprove(IERC20 token, address spender, uint256 value) internal {
                                  // safeApprove should only be called when setting an initial allowance,
                                  // or when resetting it to zero. To increase and decrease it, use
                                  // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                                  // solhint-disable-next-line max-line-length
                                  require((value == 0) || (token.allowance(address(this), spender) == 0),
                                      "SafeERC20: approve from non-zero to non-zero allowance"
                                  );
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                              }
                              function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                                  uint256 newAllowance = token.allowance(address(this), spender).add(value);
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                              }
                              function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                                  uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
                                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                              }
                              /**
                               * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                               * on the return value: the return value is optional (but if data is returned, it must not be false).
                               * @param token The token targeted by the call.
                               * @param data The call data (encoded using abi.encode or one of its variants).
                               */
                              function _callOptionalReturn(IERC20 token, bytes memory data) private {
                                  // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                                  // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                                  // the target address contains contract code and also asserts for success in the low-level call.
                                  bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                                  if (returndata.length > 0) { // Return data is optional
                                      // solhint-disable-next-line max-line-length
                                      require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                                  }
                              }
                          }
                          pragma solidity ^0.6.0;
                          import "./ISetAllowance.sol";
                          interface IAMM is ISetAllowance {
                              function trade(
                                  address _makerAddress,
                                  address _fromAssetAddress,
                                  address _toAssetAddress,
                                  uint256 _takerAssetAmount,
                                  uint256 _makerAssetAmount,
                                  uint256 _feeFactor,
                                  address _spender,
                                  address payable _receiver,
                                  uint256 _nonce,
                                  uint256 _deadline,
                                  bytes memory _sig
                              ) payable external returns (uint256);
                          }pragma solidity ^0.6.0;
                          interface ISetAllowance {
                              function setAllowance(address[] memory tokenList, address spender) external;
                              function closeAllowance(address[] memory tokenList, address spender) external;
                          }pragma solidity ^0.6.0;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "../interfaces/ISetAllowance.sol";
                          import "../interfaces/IERC1271Wallet.sol";
                          contract ERC1271WalletStub is
                              ISetAllowance,
                              IERC1271Wallet
                          {
                              using SafeERC20 for IERC20;
                              // bytes4(keccak256("isValidSignature(bytes,bytes)"))
                              bytes4 constant internal ERC1271_MAGICVALUE = 0x20c13b0b;
                              // bytes4(keccak256("isValidSignature(bytes32,bytes)"))
                              bytes4 constant internal ERC1271_MAGICVALUE_BYTES32 = 0x1626ba7e;
                              uint256 private constant MAX_UINT = 2**256 - 1;
                              address public operator;
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "Quoter: not the operator");
                                  _;
                              }
                              constructor (address _operator) public {
                                  operator = _operator;
                              }
                              function setAllowance(address[] memory _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, MAX_UINT);
                                  }
                              }
                              function closeAllowance(address[] memory _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, 0);
                                  }
                              }
                              function isValidSignature(
                                  bytes calldata _data,
                                  bytes calldata _signature)
                                  override
                                  external
                                  view
                                  returns (bytes4 magicValue)
                              {
                                  return ERC1271_MAGICVALUE;
                              }
                              function isValidSignature(
                                  bytes32 _hash,
                                  bytes calldata _signature)
                                  override
                                  external
                                  view
                                  returns (bytes4 magicValue)
                              {
                                  return ERC1271_MAGICVALUE_BYTES32;
                              }
                          }
                          pragma solidity ^0.6.0;
                          interface  IERC1271Wallet {
                            /**
                             * @notice Verifies whether the provided signature is valid with respect to the provided data
                             * @dev MUST return the correct magic value if the signature provided is valid for the provided data
                             *   > The bytes4 magic value to return when signature is valid is 0x20c13b0b : bytes4(keccak256("isValidSignature(bytes,bytes)")
                             *   > This function MAY modify Ethereum's state
                             * @param _data       Arbitrary length data signed on the behalf of address(this)
                             * @param _signature  Signature byte array associated with _data
                             * @return magicValue Magic value 0x20c13b0b if the signature is valid and 0x0 otherwise
                             *
                             */
                            function isValidSignature(
                              bytes calldata _data,
                              bytes calldata _signature)
                              external
                              view
                              returns (bytes4 magicValue);
                            /**
                             * @notice Verifies whether the provided signature is valid with respect to the provided hash
                             * @dev MUST return the correct magic value if the signature provided is valid for the provided hash
                             *   > The bytes4 magic value to return when signature is valid is 0x20c13b0b : bytes4(keccak256("isValidSignature(bytes,bytes)")
                             *   > This function MAY modify Ethereum's state
                             * @param _hash       keccak256 hash that was signed
                             * @param _signature  Signature byte array associated with _data
                             * @return magicValue Magic value 0x20c13b0b if the signature is valid and 0x0 otherwise
                             */
                            function isValidSignature(
                              bytes32 _hash,
                              bytes calldata _signature)
                              external
                              view
                              returns (bytes4 magicValue);
                          }pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "@openzeppelin/contracts/math/SafeMath.sol";
                          import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
                          import "@openzeppelin/contracts/utils/Address.sol";
                          import "./interfaces/ISpender.sol";
                          import "./interfaces/IWeth.sol";
                          import "./interfaces/IRFQ.sol";
                          import "./interfaces/IPermanentStorage.sol";
                          import "./interfaces/IERC1271Wallet.sol";
                          import "./utils/RFQLibEIP712.sol";
                          contract RFQ is
                              ReentrancyGuard,
                              IRFQ,
                              RFQLibEIP712,
                              SignatureValidator
                          {
                              using SafeMath for uint256;
                              using SafeERC20 for IERC20;
                              using Address for address;
                              // Constants do not have storage slot.
                              string public constant version = "5.2.0";
                              uint256 private constant MAX_UINT = 2**256 - 1;
                              string public constant SOURCE = "RFQ v1";
                              uint256 private constant BPS_MAX = 10000;
                              address public immutable userProxy;
                              IPermanentStorage public immutable permStorage;
                              IWETH public immutable weth;
                              // Below are the variables which consume storage slots.
                              address public operator;
                              ISpender public spender;
                              struct GroupedVars {
                                  bytes32 orderHash;
                                  bytes32 transactionHash;
                              }
                              // Operator events
                              event TransferOwnership(address newOperator);
                              event UpgradeSpender(address newSpender);
                              event AllowTransfer(address spender);
                              event DisallowTransfer(address spender);
                              event DepositETH(uint256 ethBalance);
                              event FillOrder(
                                  string source,
                                  bytes32 indexed transactionHash,
                                  bytes32 indexed orderHash,
                                  address indexed userAddr,
                                  address takerAssetAddr,
                                  uint256 takerAssetAmount,
                                  address makerAddr,
                                  address makerAssetAddr,
                                  uint256 makerAssetAmount,
                                  address receiverAddr,
                                  uint256 settleAmount,
                                  uint16 feeFactor
                              );
                              receive() external payable {}
                              /************************************************************
                              *          Access control and ownership management          *
                              *************************************************************/
                              modifier onlyOperator {
                                  require(operator == msg.sender, "RFQ: not operator");
                                  _;
                              }
                              modifier onlyUserProxy() {
                                  require(address(userProxy) == msg.sender, "RFQ: not the UserProxy contract");
                                  _;
                              }
                              function transferOwnership(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "RFQ: operator can not be zero address");
                                  operator = _newOperator;
                                  emit TransferOwnership(_newOperator);
                              }
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              constructor (
                                  address _operator, 
                                  address _userProxy, 
                                  ISpender _spender, 
                                  IPermanentStorage _permStorage, 
                                  IWETH _weth
                              ) public {
                                  operator = _operator;
                                  userProxy = _userProxy;
                                  spender = _spender;
                                  permStorage = _permStorage;
                                  weth = _weth;
                              }
                              /************************************************************
                              *           Management functions for Operator               *
                              *************************************************************/
                              /**
                               * @dev set new Spender
                               */
                              function upgradeSpender(address _newSpender) external onlyOperator {
                                  require(_newSpender != address(0), "RFQ: spender can not be zero address");
                                  spender = ISpender(_newSpender);
                                  emit UpgradeSpender(_newSpender);
                              }
                              /**
                               * @dev approve spender to transfer tokens from this contract. This is used to collect fee.
                               */
                              function setAllowance(address[] calldata _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, MAX_UINT);
                                      emit AllowTransfer(_spender);
                                  }
                              }
                              function closeAllowance(address[] calldata _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, 0);
                                      emit DisallowTransfer(_spender);
                                  }
                              }
                              /**
                               * @dev convert collected ETH to WETH
                               */
                              function depositETH() external onlyOperator {
                                  uint256 balance = address(this).balance;
                                  if (balance > 0) {
                                      weth.deposit{value: balance}();
                                      emit DepositETH(balance);
                                  }
                              }
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              function fill(
                                  RFQLibEIP712.Order memory _order,
                                  bytes memory _mmSignature,
                                  bytes memory _userSignature
                              )
                                  override
                                  payable
                                  external
                                  nonReentrant
                                  onlyUserProxy
                                  returns (uint256)
                              {
                                  // check the order deadline and fee factor
                                  require(_order.deadline >= block.timestamp, "RFQ: expired order");
                                  require(_order.feeFactor < BPS_MAX, "RFQ: invalid fee factor");
                                  GroupedVars memory vars;
                                  // Validate signatures
                                  vars.orderHash = _getOrderHash(_order);
                                  require(
                                      isValidSignature(
                                          _order.makerAddr,
                                          _getOrderSignDigestFromHash(vars.orderHash),
                                          bytes(""),
                                          _mmSignature
                                      ),
                                      "RFQ: invalid MM signature"
                                  );
                                  vars.transactionHash = _getTransactionHash(_order);
                                  require(
                                      isValidSignature(
                                          _order.takerAddr,
                                          _getTransactionSignDigestFromHash(vars.transactionHash),
                                          bytes(""),
                                          _userSignature
                                      ),
                                      "RFQ: invalid user signature"
                                  );
                                  // Set transaction as seen, PermanentStorage would throw error if transaction already seen.
                                  permStorage.setRFQTransactionSeen(vars.transactionHash);
                                  // Deposit to WETH if taker asset is ETH, else transfer from user
                                  if (address(weth) == _order.takerAssetAddr) {
                                      require(
                                          msg.value == _order.takerAssetAmount,
                                          "RFQ: insufficient ETH"
                                      );
                                      weth.deposit{value: msg.value}();
                                  } else {
                                      spender.spendFromUser(_order.takerAddr, _order.takerAssetAddr, _order.takerAssetAmount);
                                  }
                                  // Transfer from maker
                                  spender.spendFromUser(_order.makerAddr, _order.makerAssetAddr, _order.makerAssetAmount);
                                  // settle token/ETH to user
                                  return _settle(_order, vars);
                              }
                              // settle
                              function _settle(
                                  RFQLibEIP712.Order memory _order,
                                  GroupedVars memory _vars
                              ) internal returns(uint256) {
                                  // Transfer taker asset to maker
                                  IERC20(_order.takerAssetAddr).safeTransfer(_order.makerAddr, _order.takerAssetAmount);
                                  // Transfer maker asset to taker, sub fee
                                  uint256 settleAmount = _order.makerAssetAmount;
                                  if (_order.feeFactor > 0) {
                                      // settleAmount = settleAmount * (10000 - feeFactor) / 10000
                                      settleAmount = settleAmount.mul((BPS_MAX).sub(_order.feeFactor)).div(BPS_MAX);
                                  }
                                  // Transfer token/Eth to receiver
                                  if (_order.makerAssetAddr == address(weth)){
                                      weth.withdraw(settleAmount);
                                      payable(_order.receiverAddr).transfer(settleAmount);
                                  } else {
                                      IERC20(_order.makerAssetAddr).safeTransfer(_order.receiverAddr, settleAmount);
                                  }
                                  emit FillOrder(
                                      SOURCE,
                                      _vars.transactionHash,
                                      _vars.orderHash,
                                      _order.takerAddr,
                                      _order.takerAssetAddr,
                                      _order.takerAssetAmount,
                                      _order.makerAddr,
                                      _order.makerAssetAddr,
                                      _order.makerAssetAmount,
                                      _order.receiverAddr,
                                      settleAmount,
                                      uint16(_order.feeFactor)
                                  );
                                  return settleAmount;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev Contract module that helps prevent reentrant calls to a function.
                           *
                           * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
                           * available, which can be applied to functions to make sure there are no nested
                           * (reentrant) calls to them.
                           *
                           * Note that because there is a single `nonReentrant` guard, functions marked as
                           * `nonReentrant` may not call one another. This can be worked around by making
                           * those functions `private`, and then adding `external` `nonReentrant` entry
                           * points to them.
                           *
                           * TIP: If you would like to learn more about reentrancy and alternative ways
                           * to protect against it, check out our blog post
                           * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
                           */
                          abstract contract ReentrancyGuard {
                              // Booleans are more expensive than uint256 or any type that takes up a full
                              // word because each write operation emits an extra SLOAD to first read the
                              // slot's contents, replace the bits taken up by the boolean, and then write
                              // back. This is the compiler's defense against contract upgrades and
                              // pointer aliasing, and it cannot be disabled.
                              // The values being non-zero value makes deployment a bit more expensive,
                              // but in exchange the refund on every call to nonReentrant will be lower in
                              // amount. Since refunds are capped to a percentage of the total
                              // transaction's gas, it is best to keep them low in cases like this one, to
                              // increase the likelihood of the full refund coming into effect.
                              uint256 private constant _NOT_ENTERED = 1;
                              uint256 private constant _ENTERED = 2;
                              uint256 private _status;
                              constructor () internal {
                                  _status = _NOT_ENTERED;
                              }
                              /**
                               * @dev Prevents a contract from calling itself, directly or indirectly.
                               * Calling a `nonReentrant` function from another `nonReentrant`
                               * function is not supported. It is possible to prevent this from happening
                               * by making the `nonReentrant` function external, and make it call a
                               * `private` function that does the actual work.
                               */
                              modifier nonReentrant() {
                                  // On the first call to nonReentrant, _notEntered will be true
                                  require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                                  // Any calls to nonReentrant after this point will fail
                                  _status = _ENTERED;
                                  _;
                                  // By storing the original value once again, a refund is triggered (see
                                  // https://eips.ethereum.org/EIPS/eip-2200)
                                  _status = _NOT_ENTERED;
                              }
                          }
                          pragma solidity ^0.6.0;
                          interface ISpender {
                              function spendFromUser(address _user, address _tokenAddr, uint256 _amount) external;
                              function spendFromUserTo(address _user, address _tokenAddr, address _receiverAddr, uint256 _amount) external;
                          }
                          pragma solidity ^0.6.0;
                          interface IWETH {
                              function balanceOf(address account) external view returns (uint256);
                              function deposit() external payable;
                              function withdraw(uint256 amount) external;
                              function transferFrom(address src, address dst, uint wad) external returns (bool);
                          }pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "../utils/RFQLibEIP712.sol";
                          import "./ISetAllowance.sol";
                          interface IRFQ is ISetAllowance {
                              function fill(
                                  RFQLibEIP712.Order memory _order,
                                  bytes memory _mmSignature,
                                  bytes memory _userSignature
                              ) external payable returns (uint256);
                          }pragma solidity ^0.6.0;
                          interface IPermanentStorage {
                              function wethAddr() external view returns (address);
                              function getCurvePoolInfo(address _makerAddr, address _takerAssetAddr, address _makerAssetAddr) external view returns (int128 takerAssetIndex, int128 makerAssetIndex, uint16 swapMethod, bool supportGetDx);
                              function setCurvePoolInfo(address _makerAddr, address[] calldata _underlyingCoins, address[] calldata _coins, bool _supportGetDx) external;
                              function isTransactionSeen(bytes32 _transactionHash) external view returns (bool);  // Kept for backward compatability. Should be removed from AMM 5.2.1 upward
                              function isAMMTransactionSeen(bytes32 _transactionHash) external view returns (bool);
                              function isRFQTransactionSeen(bytes32 _transactionHash) external view returns (bool);
                              function isRelayerValid(address _relayer) external view returns (bool);
                              function setTransactionSeen(bytes32 _transactionHash) external;  // Kept for backward compatability. Should be removed from AMM 5.2.1 upward
                              function setAMMTransactionSeen(bytes32 _transactionHash) external;
                              function setRFQTransactionSeen(bytes32 _transactionHash) external;
                              function setRelayersValid(address[] memory _relayers, bool[] memory _isValids) external;
                          }pragma solidity ^0.6.0;
                          import "./BaseLibEIP712.sol";
                          import "./SignatureValidator.sol";
                          contract RFQLibEIP712 is BaseLibEIP712 {
                              /***********************************|
                              |             Constants             |
                              |__________________________________*/
                              
                              struct Order {
                                  address takerAddr;
                                  address makerAddr;
                                  address takerAssetAddr;
                                  address makerAssetAddr;
                                  uint256 takerAssetAmount;
                                  uint256 makerAssetAmount;
                                  address receiverAddr;
                                  uint256 salt;
                                  uint256 deadline;
                                  uint256 feeFactor;
                              }
                              bytes32 public constant ORDER_TYPEHASH = keccak256(
                                  abi.encodePacked(
                                      "Order(",
                                      "address takerAddr,",
                                      "address makerAddr,",
                                      "address takerAssetAddr,",
                                      "address makerAssetAddr,",
                                      "uint256 takerAssetAmount,",
                                      "uint256 makerAssetAmount,",
                                      "uint256 salt,",
                                      "uint256 deadline,",
                                      "uint256 feeFactor",
                                      ")"
                                  )
                              );
                              function _getOrderHash(Order memory _order) internal pure returns (bytes32 orderHash) {
                                  orderHash = keccak256(
                                      abi.encode(
                                          ORDER_TYPEHASH,
                                          _order.takerAddr,
                                          _order.makerAddr,
                                          _order.takerAssetAddr,
                                          _order.makerAssetAddr,
                                          _order.takerAssetAmount,
                                          _order.makerAssetAmount,
                                          _order.salt,
                                          _order.deadline,
                                          _order.feeFactor
                                      )
                                  );
                              }
                              function _getOrderSignDigest(Order memory _order) internal view returns (bytes32 orderSignDigest) {
                                  orderSignDigest = keccak256(
                                      abi.encodePacked(
                                          EIP191_HEADER,
                                          EIP712_DOMAIN_SEPARATOR,
                                          _getOrderHash(_order)
                                      )
                                  );
                              }
                              function _getOrderSignDigestFromHash(bytes32 _orderHash) internal view returns (bytes32 orderSignDigest) {
                                  orderSignDigest = keccak256(
                                      abi.encodePacked(
                                          EIP191_HEADER,
                                          EIP712_DOMAIN_SEPARATOR,
                                          _orderHash
                                      )
                                  );
                              }
                              bytes32 public constant FILL_WITH_PERMIT_TYPEHASH = keccak256(
                                  abi.encodePacked(
                                      "fillWithPermit(",
                                      "address makerAddr,",
                                      "address takerAssetAddr,",
                                      "address makerAssetAddr,",
                                      "uint256 takerAssetAmount,",
                                      "uint256 makerAssetAmount,",
                                      "address takerAddr,",
                                      "address receiverAddr,",
                                      "uint256 salt,",
                                      "uint256 deadline,",
                                      "uint256 feeFactor",
                                      ")"
                                  )
                              );
                              function _getTransactionHash(Order memory _order) internal pure returns(bytes32 transactionHash) {
                                  transactionHash = keccak256(
                                      abi.encode(
                                          FILL_WITH_PERMIT_TYPEHASH,
                                          _order.makerAddr,
                                          _order.takerAssetAddr,
                                          _order.makerAssetAddr,
                                          _order.takerAssetAmount,
                                          _order.makerAssetAmount,
                                          _order.takerAddr,
                                          _order.receiverAddr,
                                          _order.salt,
                                          _order.deadline,
                                          _order.feeFactor
                                      )
                                  );
                              }
                              function _getTransactionSignDigest(Order memory _order) internal view returns (bytes32 transactionSignDigest) {
                                  transactionSignDigest = keccak256(
                                      abi.encodePacked(
                                          EIP191_HEADER,
                                          EIP712_DOMAIN_SEPARATOR,
                                          _getTransactionHash(_order)
                                      )
                                  );
                              }
                              function _getTransactionSignDigestFromHash(bytes32 _txHash) internal view returns (bytes32 transactionSignDigest) {
                                  transactionSignDigest = keccak256(
                                      abi.encodePacked(
                                          EIP191_HEADER,
                                          EIP712_DOMAIN_SEPARATOR,
                                          _txHash
                                      )
                                  );
                              }
                          }pragma solidity ^0.6.0;
                          contract BaseLibEIP712 {
                              /***********************************|
                              |             Constants             |
                              |__________________________________*/
                              // EIP-191 Header
                              string public constant EIP191_HEADER = "\\x19\\x01";
                              // EIP712Domain
                              string public constant EIP712_DOMAIN_NAME = "Tokenlon";
                              string public constant EIP712_DOMAIN_VERSION = "v5";
                              // EIP712Domain Separator
                              bytes32 public immutable EIP712_DOMAIN_SEPARATOR = keccak256(
                                  abi.encode(
                                      keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                                      keccak256(bytes(EIP712_DOMAIN_NAME)),
                                      keccak256(bytes(EIP712_DOMAIN_VERSION)),
                                      getChainID(),
                                      address(this)
                                  )
                              );
                              /**
                                  * @dev Return `chainId`
                                  */
                              function getChainID() internal pure returns (uint) {
                                  uint chainId;
                                  assembly {
                                      chainId := chainid()
                                  }
                                  return chainId;
                              }
                          }pragma solidity ^0.6.0;
                          import "../interfaces/IERC1271Wallet.sol";
                          import "./LibBytes.sol";
                          interface IWallet {
                              /// @dev Verifies that a signature is valid.
                              /// @param hash Message hash that is signed.
                              /// @param signature Proof of signing.
                              /// @return isValid Validity of order signature.
                              function isValidSignature(
                                  bytes32 hash,
                                  bytes memory signature
                              )
                                  external
                                  view
                                  returns (bool isValid);
                          }
                          /**
                           * @dev Contains logic for signature validation.
                           * Signatures from wallet contracts assume ERC-1271 support (https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1271.md)
                           * Notes: Methods are strongly inspired by contracts in https://github.com/0xProject/0x-monorepo/blob/development/
                           */
                          contract SignatureValidator {
                            using LibBytes for bytes;
                            /***********************************|
                            |             Variables             |
                            |__________________________________*/
                            // bytes4(keccak256("isValidSignature(bytes,bytes)"))
                            bytes4 constant internal ERC1271_MAGICVALUE = 0x20c13b0b;
                            // bytes4(keccak256("isValidSignature(bytes32,bytes)"))
                            bytes4 constant internal ERC1271_MAGICVALUE_BYTES32 = 0x1626ba7e;
                            // keccak256("isValidWalletSignature(bytes32,address,bytes)")
                            bytes4 constant internal ERC1271_FALLBACK_MAGICVALUE_BYTES32 = 0xb0671381;
                            // Allowed signature types.
                            enum SignatureType {
                              Illegal,                     // 0x00, default value
                              Invalid,                     // 0x01
                              EIP712,                      // 0x02
                              EthSign,                     // 0x03
                              WalletBytes,                 // 0x04  standard 1271 wallet type
                              WalletBytes32,               // 0x05  standard 1271 wallet type
                              Wallet,                      // 0x06  0x wallet type for signature compatibility
                              NSignatureTypes              // 0x07, number of signature types. Always leave at end.
                            }
                            /***********************************|
                            |        Signature Functions        |
                            |__________________________________*/
                            /**
                             * @dev Verifies that a hash has been signed by the given signer.
                             * @param _signerAddress  Address that should have signed the given hash.
                             * @param _hash           Hash of the EIP-712 encoded data
                             * @param _data           Full EIP-712 data structure that was hashed and signed
                             * @param _sig            Proof that the hash has been signed by signer.
                             *      For non wallet signatures, _sig is expected to be an array tightly encoded as
                             *      (bytes32 r, bytes32 s, uint8 v, uint256 nonce, SignatureType sigType)
                             * @return isValid True if the address recovered from the provided signature matches the input signer address.
                             */
                            function isValidSignature(
                              address _signerAddress,
                              bytes32 _hash,
                              bytes memory _data,
                              bytes memory _sig
                            )
                              public
                              view
                              returns (bool isValid)
                            {
                              require(
                                _sig.length > 0,
                                "SignatureValidator#isValidSignature: length greater than 0 required"
                              );
                              require(
                                _signerAddress != address(0x0),
                                "SignatureValidator#isValidSignature: invalid signer"
                              );
                              // Pop last byte off of signature byte array.
                              uint8 signatureTypeRaw = uint8(_sig.popLastByte());
                              // Ensure signature is supported
                              require(
                                signatureTypeRaw < uint8(SignatureType.NSignatureTypes),
                                "SignatureValidator#isValidSignature: unsupported signature"
                              );
                              // Extract signature type
                              SignatureType signatureType = SignatureType(signatureTypeRaw);
                              // Variables are not scoped in Solidity.
                              uint8 v;
                              bytes32 r;
                              bytes32 s;
                              address recovered;
                              // Always illegal signature.
                              // This is always an implicit option since a signer can create a
                              // signature array with invalid type or length. We may as well make
                              // it an explicit option. This aids testing and analysis. It is
                              // also the initialization value for the enum type.
                              if (signatureType == SignatureType.Illegal) {
                                revert("SignatureValidator#isValidSignature: illegal signature");
                              // Signature using EIP712
                              } else if (signatureType == SignatureType.EIP712) {
                                require(
                                  _sig.length == 97,
                                  "SignatureValidator#isValidSignature: length 97 required"
                                );
                                r = _sig.readBytes32(0);
                                s = _sig.readBytes32(32);
                                v = uint8(_sig[64]);
                                recovered = ecrecover(_hash, v, r, s);
                                isValid = _signerAddress == recovered;
                                return isValid;
                              // Signed using web3.eth_sign() or Ethers wallet.signMessage()
                              } else if (signatureType == SignatureType.EthSign) {
                                require(
                                  _sig.length == 97,
                                  "SignatureValidator#isValidSignature: length 97 required"
                                );
                                r = _sig.readBytes32(0);
                                s = _sig.readBytes32(32);
                                v = uint8(_sig[64]);
                                recovered = ecrecover(
                                  keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
                          32", _hash)),
                                  v,
                                  r,
                                  s
                                );
                                isValid = _signerAddress == recovered;
                                return isValid;
                              // Signature verified by wallet contract with data validation.
                              } else if (signatureType == SignatureType.WalletBytes) {
                                isValid = ERC1271_MAGICVALUE == IERC1271Wallet(_signerAddress).isValidSignature(_data, _sig);
                                return isValid;
                              // Signature verified by wallet contract without data validation.
                              } else if (signatureType == SignatureType.WalletBytes32) {
                                isValid = ERC1271_MAGICVALUE_BYTES32 == IERC1271Wallet(_signerAddress).isValidSignature(_hash, _sig);
                                return isValid;
                              } else if (signatureType == SignatureType.Wallet) {
                                isValid = isValidWalletSignature(
                                    _hash,
                                    _signerAddress,
                                    _sig
                                );
                                return isValid;
                              }
                              // Anything else is illegal (We do not return false because
                              // the signature may actually be valid, just not in a format
                              // that we currently support. In this case returning false
                              // may lead the caller to incorrectly believe that the
                              // signature was invalid.)
                              revert("SignatureValidator#isValidSignature: unsupported signature");
                            }
                            /// @dev Verifies signature using logic defined by Wallet contract.
                            /// @param hash Any 32 byte hash.
                            /// @param walletAddress Address that should have signed the given hash
                            ///                      and defines its own signature verification method.
                            /// @param signature Proof that the hash has been signed by signer.
                            /// @return isValid True if signature is valid for given wallet..
                            function isValidWalletSignature(
                                bytes32 hash,
                                address walletAddress,
                                bytes memory signature
                            )
                                internal
                                view
                                returns (bool isValid)
                            {
                                bytes memory _calldata = abi.encodeWithSelector(
                                    IWallet(walletAddress).isValidSignature.selector,
                                    hash,
                                    signature
                                );
                                bytes32 magic_salt = bytes32(bytes4(keccak256("isValidWalletSignature(bytes32,address,bytes)")));
                                assembly {
                                    if iszero(extcodesize(walletAddress)) {
                                        // Revert with `Error("WALLET_ERROR")`
                                        mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                                        mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
                                        mstore(64, 0x0000000c57414c4c45545f4552524f5200000000000000000000000000000000)
                                        mstore(96, 0)
                                        revert(0, 100)
                                    }
                                    let cdStart := add(_calldata, 32)
                                    let success := staticcall(
                                        gas(),              // forward all gas
                                        walletAddress,    // address of Wallet contract
                                        cdStart,          // pointer to start of input
                                        mload(_calldata),  // length of input
                                        cdStart,          // write output over input
                                        32                // output size is 32 bytes
                                    )
                                    if iszero(eq(returndatasize(), 32)) {
                                        // Revert with `Error("WALLET_ERROR")`
                                        mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                                        mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
                                        mstore(64, 0x0000000c57414c4c45545f4552524f5200000000000000000000000000000000)
                                        mstore(96, 0)
                                        revert(0, 100)
                                    }
                                    switch success
                                    case 0 {
                                        // Revert with `Error("WALLET_ERROR")`
                                        mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
                                        mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
                                        mstore(64, 0x0000000c57414c4c45545f4552524f5200000000000000000000000000000000)
                                        mstore(96, 0)
                                        revert(0, 100)
                                    }
                                    case 1 {
                                        // Signature is valid if call did not revert and returned true
                                        isValid := eq(
                                            and(mload(cdStart), 0xffffffff00000000000000000000000000000000000000000000000000000000),
                                            and(magic_salt, 0xffffffff00000000000000000000000000000000000000000000000000000000)
                                        )
                                    }
                                }
                                return isValid;
                            }
                          }
                          /*
                            Copyright 2018 ZeroEx Intl.
                            Licensed under the Apache License, Version 2.0 (the "License");
                            you may not use this file except in compliance with the License.
                            You may obtain a copy of the License at
                            http://www.apache.org/licenses/LICENSE-2.0
                            Unless required by applicable law or agreed to in writing, software
                            distributed under the License is distributed on an "AS IS" BASIS,
                            WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                            See the License for the specific language governing permissions and
                            limitations under the License.
                            This is a truncated version of the original LibBytes.sol library from ZeroEx.
                          */
                          pragma solidity ^0.6.0;
                          library LibBytes {
                            using LibBytes for bytes;
                            /***********************************|
                            |        Pop Bytes Functions        |
                            |__________________________________*/
                            /**
                             * @dev Pops the last byte off of a byte array by modifying its length.
                             * @param b Byte array that will be modified.
                             * @return result The byte that was popped off.
                             */
                            function popLastByte(bytes memory b)
                              internal
                              pure
                              returns (bytes1 result)
                            {
                              require(
                                b.length > 0,
                                "LibBytes#popLastByte: greater than zero length required"
                              );
                              // Store last byte.
                              result = b[b.length - 1];
                              assembly {
                                // Decrement length of byte array.
                                let newLen := sub(mload(b), 1)
                                mstore(b, newLen)
                              }
                              return result;
                            }
                            /// @dev Reads an address from a position in a byte array.
                            /// @param b Byte array containing an address.
                            /// @param index Index in byte array of address.
                            /// @return result address from byte array.
                            function readAddress(
                              bytes memory b,
                              uint256 index
                            )
                              internal
                              pure
                              returns (address result)
                            {
                              require(
                                b.length >= index + 20,  // 20 is length of address
                                "LibBytes#readAddress greater or equal to 20 length required"
                              );
                              // Add offset to index:
                              // 1. Arrays are prefixed by 32-byte length parameter (add 32 to index)
                              // 2. Account for size difference between address length and 32-byte storage word (subtract 12 from index)
                              index += 20;
                              // Read address from array memory
                              assembly {
                                // 1. Add index to address of bytes array
                                // 2. Load 32-byte word from memory
                                // 3. Apply 20-byte mask to obtain address
                                result := and(mload(add(b, index)), 0xffffffffffffffffffffffffffffffffffffffff)
                              }
                              return result;
                            }
                            /***********************************|
                            |        Read Bytes Functions       |
                            |__________________________________*/
                            /**
                             * @dev Reads a bytes32 value from a position in a byte array.
                             * @param b Byte array containing a bytes32 value.
                             * @param index Index in byte array of bytes32 value.
                             * @return result bytes32 value from byte array.
                             */
                            function readBytes32(
                              bytes memory b,
                              uint256 index
                            )
                              internal
                              pure
                              returns (bytes32 result)
                            {
                              require(
                                b.length >= index + 32,
                                "LibBytes#readBytes32 greater or equal to 32 length required"
                              );
                              // Arrays are prefixed by a 256 bit length parameter
                              index += 32;
                              // Read the bytes32 from array memory
                              assembly {
                                result := mload(add(b, index))
                              }
                              return result;
                            }
                            /// @dev Reads an unpadded bytes4 value from a position in a byte array.
                            /// @param b Byte array containing a bytes4 value.
                            /// @param index Index in byte array of bytes4 value.
                            /// @return result bytes4 value from byte array.
                            function readBytes4(
                              bytes memory b,
                              uint256 index
                            )
                              internal
                              pure
                              returns (bytes4 result)
                            {
                              require(
                                b.length >= index + 4,
                                "LibBytes#readBytes4 greater or equal to 4 length required"
                              );
                              // Arrays are prefixed by a 32 byte length field
                              index += 32;
                              // Read the bytes4 from array memory
                              assembly {
                                result := mload(add(b, index))
                                // Solidity does not require us to clean the trailing bytes.
                                // We do it anyway
                                result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
                              }
                              return result;
                            }
                            function readBytes2(
                              bytes memory b,
                              uint256 index
                            )
                              internal
                              pure
                              returns (bytes2 result)
                            {
                              require(
                                b.length >= index + 2,
                                "LibBytes#readBytes2 greater or equal to 2 length required"
                              );
                              // Arrays are prefixed by a 32 byte length field
                              index += 32;
                              // Read the bytes4 from array memory
                              assembly {
                                result := mload(add(b, index))
                                // Solidity does not require us to clean the trailing bytes.
                                // We do it anyway
                                result := and(result, 0xFFFF000000000000000000000000000000000000000000000000000000000000)
                              }
                              return result;
                            }
                          }pragma solidity 0.6.12;
                          import "../utils/LibBytes.sol";
                          import "./MultiSigLibEIP712.sol";
                          /**
                           * @title MultiSig
                           * @author dYdX
                           *
                           * Multi-Signature Wallet.
                           * Allows multiple parties to agree on transactions before execution.
                           * Adapted from Stefan George's MultiSigWallet contract.
                           *
                           * Logic Changes:
                           *  - Removed the fallback function
                           *  - Ensure newOwner is notNull
                           *
                           * Syntax Changes:
                           *  - Update Solidity syntax for 0.5.X: use `emit` keyword (events), use `view` keyword (functions)
                           *  - Add braces to all `if` and `for` statements
                           *  - Remove named return variables
                           *  - Add space before and after comparison operators
                           *  - Add ADDRESS_ZERO as a constant
                           *  - uint => uint256
                           *  - external_call => externalCall
                           */
                          contract MultiSig is MultiSigLibEIP712 {
                              using LibBytes for bytes;
                              // ============ Events ============
                              event Deposit(address indexed depositer, uint256 amount);
                              event Confirmation(address indexed sender, uint256 indexed transactionId);
                              event Revocation(address indexed sender, uint256 indexed transactionId);
                              event Submission(uint256 indexed transactionId);
                              event Execution(uint256 indexed transactionId);
                              event ExecutionFailure(uint256 indexed transactionId);
                              event OwnerAddition(address indexed owner);
                              event OwnerRemoval(address indexed owner);
                              event RequirementChange(uint256 required);
                              // ============ Constants ============
                              uint256 constant public MAX_OWNER_COUNT = 50;
                              address constant ADDRESS_ZERO = address(0x0);
                              // ============ Storage ============
                              mapping (uint256 => Transaction) public transactions;
                              mapping (uint256 => mapping (address => bool)) public confirmations;
                              mapping (address => bool) public isOwner;
                              address[] public owners;
                              uint256 public required;
                              uint256 public transactionCount;
                              // ============ Structs ============
                              struct Transaction {
                                  address destination;
                                  uint256 value;
                                  bytes data;
                                  bool executed;
                              }
                              // ============ Modifiers ============
                              modifier onlyWallet() {
                                  /* solium-disable-next-line error-reason */
                                  require(msg.sender == address(this));
                                  _;
                              }
                              modifier ownerDoesNotExist(
                                  address owner
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(!isOwner[owner]);
                                  _;
                              }
                              modifier ownerExists(
                                  address owner
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(isOwner[owner]);
                                  _;
                              }
                              modifier transactionExists(
                                  uint256 transactionId
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(transactions[transactionId].destination != ADDRESS_ZERO);
                                  _;
                              }
                              modifier confirmed(
                                  uint256 transactionId,
                                  address owner
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(confirmations[transactionId][owner]);
                                  _;
                              }
                              modifier notConfirmed(
                                  uint256 transactionId,
                                  address owner
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(!confirmations[transactionId][owner]);
                                  _;
                              }
                              modifier notExecuted(
                                  uint256 transactionId
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(!transactions[transactionId].executed);
                                  _;
                              }
                              modifier notNull(
                                  address _address
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(_address != ADDRESS_ZERO);
                                  _;
                              }
                              modifier validRequirement(
                                  uint256 ownerCount,
                                  uint256 _required
                              ) {
                                  /* solium-disable-next-line error-reason */
                                  require(
                                      ownerCount <= MAX_OWNER_COUNT
                                      && _required <= ownerCount
                                      && _required != 0
                                      && ownerCount != 0
                                  );
                                  _;
                              }
                              // ========= Fallback function ==========
                              receive() external payable {
                                  emit Deposit(msg.sender, msg.value);
                              }
                              // ============ Constructor ============
                              /**
                               * Contract constructor sets initial owners and required number of confirmations.
                               *
                               * @param  _owners    List of initial owners.
                               * @param  _required  Number of required confirmations.
                               */
                              constructor(
                                  address[] memory _owners,
                                  uint256 _required
                              )
                                  public
                                  validRequirement(_owners.length, _required)
                                  MultiSigLibEIP712()
                              {
                                  for (uint256 i = 0; i < _owners.length; i++) {
                                      /* solium-disable-next-line error-reason */
                                      require(!isOwner[_owners[i]] && _owners[i] != ADDRESS_ZERO);
                                      isOwner[_owners[i]] = true;
                                  }
                                  owners = _owners;
                                  required = _required;
                              }
                              // ============ Wallet-Only Functions ============
                              /**
                               * Allows to add a new owner. Transaction has to be sent by wallet.
                               *
                               * @param  owner  Address of new owner.
                               */
                              function addOwner(
                                  address owner
                              )
                                  public
                                  onlyWallet
                                  ownerDoesNotExist(owner)
                                  notNull(owner)
                                  validRequirement(owners.length + 1, required)
                              {
                                  isOwner[owner] = true;
                                  owners.push(owner);
                                  emit OwnerAddition(owner);
                              }
                              /**
                               * Allows to remove an owner. Transaction has to be sent by wallet.
                               *
                               * @param  owner  Address of owner.
                               */
                              function removeOwner(
                                  address owner
                              )
                                  public
                                  onlyWallet
                                  ownerExists(owner)
                              {
                                  isOwner[owner] = false;
                                  for (uint256 i = 0; i < owners.length - 1; i++) {
                                      if (owners[i] == owner) {
                                          owners[i] = owners[owners.length - 1];
                                          break;
                                      }
                                  }
                                  delete owners[owners.length - 1];
                                  if (required > owners.length) {
                                      changeRequirement(owners.length);
                                  }
                                  emit OwnerRemoval(owner);
                              }
                              /**
                               * Allows to replace an owner with a new owner. Transaction has to be sent by wallet.
                               *
                               * @param  owner     Address of owner to be replaced.
                               * @param  newOwner  Address of new owner.
                               */
                              function replaceOwner(
                                  address owner,
                                  address newOwner
                              )
                                  public
                                  onlyWallet
                                  ownerExists(owner)
                                  ownerDoesNotExist(newOwner)
                                  notNull(newOwner)
                              {
                                  for (uint256 i = 0; i < owners.length; i++) {
                                      if (owners[i] == owner) {
                                          owners[i] = newOwner;
                                          break;
                                      }
                                  }
                                  isOwner[owner] = false;
                                  isOwner[newOwner] = true;
                                  emit OwnerRemoval(owner);
                                  emit OwnerAddition(newOwner);
                              }
                              /**
                               * Allows to change the number of required confirmations. Transaction has to be sent by wallet.
                               *
                               * @param  _required  Number of required confirmations.
                               */
                              function changeRequirement(
                                  uint256 _required
                              )
                                  public
                                  onlyWallet
                                  validRequirement(owners.length, _required)
                              {
                                  required = _required;
                                  emit RequirementChange(_required);
                              }
                              // ============ Owner Functions ============
                              /**
                               * Allows an owner to submit and confirm a transaction.
                               *
                               * @param  destination  Transaction target address.
                               * @param  value        Transaction ether value.
                               * @param  data         Transaction data payload.
                               * @return              Transaction ID.
                               */
                              function submitTransaction(
                                  address destination,
                                  uint256 value,
                                  bytes memory data
                              )
                                  public
                                  returns (uint256)
                              {
                                  uint256 transactionId = addTransaction(destination, value, data);
                                  confirmTransaction(transactionId);
                                  return transactionId;
                              }
                              /**
                               * Allows an owner to submit and confirm a transaction via meta transaction.
                               *
                               * @param  signer           Signer of the meta transaction.
                               * @param  transactionId    Transaction ID of this transaction.
                               * @param  destination      Transaction target address.
                               * @param  value            Transaction ether value.
                               * @param  data             Transaction data payload.
                               * @param  sig              Signature.
                               * @return                  Transaction ID.
                               */
                              function submitTransaction(
                                  address signer,
                                  uint256 transactionId,
                                  address destination,
                                  uint256 value,
                                  bytes memory data,
                                  bytes memory sig
                              )
                                  public
                                  ownerExists(signer)
                                  returns (uint256)
                              {
                                  // SUBMIT_TRANSACTION_TYPE_HASH = keccak256("submitTransaction(uint256 transactionId,address destination,uint256 value,bytes data)");
                                  bytes32 EIP712SignDigest = keccak256(
                                      abi.encodePacked(
                                          bytes1(0x19),
                                          bytes1(0x01),
                                          EIP712_DOMAIN_SEPARATOR,
                                          keccak256(
                                              abi.encode(
                                                  SUBMIT_TRANSACTION_TYPE_HASH,
                                                  transactionId,
                                                  destination,
                                                  value,
                                                  data
                                              )
                                          )
                                      )
                                  );
                                  validateSignature(signer, EIP712SignDigest, sig);
                                  uint256 _transactionId = addTransaction(destination, value, data);
                                  require(transactionId == _transactionId);
                                  confirmTransactionBySigner(signer, transactionId);
                                  return transactionId;
                              }
                              // confirm transaction on behalf of signer, not msg.sender
                              function confirmTransactionBySigner(
                                  address signer,
                                  uint256 transactionId
                              )
                                  internal
                                  transactionExists(transactionId)
                                  notConfirmed(transactionId, signer)
                              {
                                  // Confirm
                                  confirmations[transactionId][signer] = true;
                                  emit Confirmation(signer, transactionId);
                                  // Execute
                                  executeTransactionBySigner(signer, transactionId);
                              }
                              // execute transaction on behalf of signer, not msg.sender
                              function executeTransactionBySigner(
                                  address signer,
                                  uint256 transactionId
                              )
                                  internal
                                  notExecuted(transactionId)
                              {
                                  if (isConfirmed(transactionId)) {
                                      Transaction storage txn = transactions[transactionId];
                                      txn.executed = true;
                                      if (externalCall(
                                          txn.destination,
                                          txn.value,
                                          txn.data.length,
                                          txn.data)
                                      ) {
                                          emit Execution(transactionId);
                                      } else {
                                          emit ExecutionFailure(transactionId);
                                          txn.executed = false;
                                      }
                                  }
                              }
                              /**
                               * Allows an owner to confirm a transaction.
                               *
                               * @param  transactionId  Transaction ID.
                               */
                              function confirmTransaction(
                                  uint256 transactionId
                              )
                                  public
                                  virtual
                                  ownerExists(msg.sender)
                                  transactionExists(transactionId)
                                  notConfirmed(transactionId, msg.sender)
                              {
                                  confirmations[transactionId][msg.sender] = true;
                                  emit Confirmation(msg.sender, transactionId);
                                  executeTransaction(transactionId);
                              }
                              /**
                               * Allows an owner to confirm a transaction via meta transaction.
                               *
                               * @param  signer           Signer of the meta transaction.
                               * @param  transactionId    Transaction ID.
                               * @param  sig              Signature.
                               */
                              function confirmTransaction(
                                  address signer,
                                  uint256 transactionId,
                                  bytes memory sig
                              )
                                  public
                                  virtual
                                  ownerExists(signer)
                                  transactionExists(transactionId)
                                  notConfirmed(transactionId, signer)
                              {
                                  // CONFIRM_TRANSACTION_TYPE_HASH = keccak256("confirmTransaction(uint256 transactionId)");
                                  bytes32 EIP712SignDigest = keccak256(
                                      abi.encodePacked(
                                          bytes1(0x19),
                                          bytes1(0x01),
                                          EIP712_DOMAIN_SEPARATOR,
                                          keccak256(
                                              abi.encode(
                                                  CONFIRM_TRANSACTION_TYPE_HASH,
                                                  transactionId
                                              )
                                          )
                                      )
                                  );
                                  validateSignature(signer, EIP712SignDigest, sig);
                                  confirmations[transactionId][signer] = true;
                                  emit Confirmation(signer, transactionId);
                                  executeTransactionBySigner(signer, transactionId);
                              }
                              /**
                               * Allows an owner to revoke a confirmation for a transaction.
                               *
                               * @param  transactionId  Transaction ID.
                               */
                              function revokeConfirmation(
                                  uint256 transactionId
                              )
                                  public
                                  ownerExists(msg.sender)
                                  confirmed(transactionId, msg.sender)
                                  notExecuted(transactionId)
                              {
                                  confirmations[transactionId][msg.sender] = false;
                                  emit Revocation(msg.sender, transactionId);
                              }
                              /**
                               * Allows an owner to execute a confirmed transaction.
                               *
                               * @param  transactionId  Transaction ID.
                               */
                              function executeTransaction(
                                  uint256 transactionId
                              )
                                  public
                                  virtual
                                  ownerExists(msg.sender)
                                  confirmed(transactionId, msg.sender)
                                  notExecuted(transactionId)
                              {
                                  if (isConfirmed(transactionId)) {
                                      Transaction storage txn = transactions[transactionId];
                                      txn.executed = true;
                                      if (externalCall(
                                          txn.destination,
                                          txn.value,
                                          txn.data.length,
                                          txn.data)
                                      ) {
                                          emit Execution(transactionId);
                                      } else {
                                          emit ExecutionFailure(transactionId);
                                          txn.executed = false;
                                      }
                                  }
                              }
                              // ============ Getter Functions ============
                              /**
                               * Returns the confirmation status of a transaction.
                               *
                               * @param  transactionId  Transaction ID.
                               * @return                Confirmation status.
                               */
                              function isConfirmed(
                                  uint256 transactionId
                              )
                                  public
                                  view
                                  returns (bool)
                              {
                                  uint256 count = 0;
                                  for (uint256 i = 0; i < owners.length; i++) {
                                      if (confirmations[transactionId][owners[i]]) {
                                          count += 1;
                                      }
                                      if (count == required) {
                                          return true;
                                      }
                                  }
                              }
                              /**
                               * Returns number of confirmations of a transaction.
                               *
                               * @param  transactionId  Transaction ID.
                               * @return                Number of confirmations.
                               */
                              function getConfirmationCount(
                                  uint256 transactionId
                              )
                                  public
                                  view
                                  returns (uint256)
                              {
                                  uint256 count = 0;
                                  for (uint256 i = 0; i < owners.length; i++) {
                                      if (confirmations[transactionId][owners[i]]) {
                                          count += 1;
                                      }
                                  }
                                  return count;
                              }
                              /**
                               * Returns total number of transactions after filers are applied.
                               *
                               * @param  pending   Include pending transactions.
                               * @param  executed  Include executed transactions.
                               * @return           Total number of transactions after filters are applied.
                               */
                              function getTransactionCount(
                                  bool pending,
                                  bool executed
                              )
                                  public
                                  view
                                  returns (uint256)
                              {
                                  uint256 count = 0;
                                  for (uint256 i = 0; i < transactionCount; i++) {
                                      if (
                                          pending && !transactions[i].executed
                                          || executed && transactions[i].executed
                                      ) {
                                          count += 1;
                                      }
                                  }
                                  return count;
                              }
                              /**
                               * Returns array of owners.
                               *
                               * @return  Array of owner addresses.
                               */
                              function getOwners()
                                  public
                                  view
                                  returns (address[] memory)
                              {
                                  return owners;
                              }
                              /**
                               * Returns array with owner addresses, which confirmed transaction.
                               *
                               * @param  transactionId  Transaction ID.
                               * @return                Array of owner addresses.
                               */
                              function getConfirmations(
                                  uint256 transactionId
                              )
                                  public
                                  view
                                  returns (address[] memory)
                              {
                                  address[] memory confirmationsTemp = new address[](owners.length);
                                  uint256 count = 0;
                                  uint256 i;
                                  for (i = 0; i < owners.length; i++) {
                                      if (confirmations[transactionId][owners[i]]) {
                                          confirmationsTemp[count] = owners[i];
                                          count += 1;
                                      }
                                  }
                                  address[] memory _confirmations = new address[](count);
                                  for (i = 0; i < count; i++) {
                                      _confirmations[i] = confirmationsTemp[i];
                                  }
                                  return _confirmations;
                              }
                              /**
                               * Returns list of transaction IDs in defined range.
                               *
                               * @param  from      Index start position of transaction array.
                               * @param  to        Index end position of transaction array.
                               * @param  pending   Include pending transactions.
                               * @param  executed  Include executed transactions.
                               * @return           Array of transaction IDs.
                               */
                              function getTransactionIds(
                                  uint256 from,
                                  uint256 to,
                                  bool pending,
                                  bool executed
                              )
                                  public
                                  view
                                  returns (uint256[] memory)
                              {
                                  uint256[] memory transactionIdsTemp = new uint256[](transactionCount);
                                  uint256 count = 0;
                                  uint256 i;
                                  for (i = 0; i < transactionCount; i++) {
                                      if (
                                          pending && !transactions[i].executed
                                          || executed && transactions[i].executed
                                      ) {
                                          transactionIdsTemp[count] = i;
                                          count += 1;
                                      }
                                  }
                                  uint256[] memory _transactionIds = new uint256[](to - from);
                                  for (i = from; i < to; i++) {
                                      _transactionIds[i - from] = transactionIdsTemp[i];
                                  }
                                  return _transactionIds;
                              }
                              // ============ Helper Functions ============
                              function validateSignature(
                                  address signer,
                                  bytes32 digest,
                                  bytes memory sig
                              )
                                  internal
                              {
                                  require(sig.length == 65);
                                  uint8 v = uint8(sig[64]);
                                  bytes32 r = sig.readBytes32(0);
                                  bytes32 s = sig.readBytes32(32);
                                  address recovered = ecrecover(digest, v, r, s);
                                  require(signer == recovered);
                              }
                              // call has been separated into its own function in order to take advantage
                              // of the Solidity's code generator to produce a loop that copies tx.data into memory.
                              function externalCall(
                                  address destination,
                                  uint256 value,
                                  uint256 dataLength,
                                  bytes memory data
                              )
                                  internal
                                  returns (bool)
                              {
                                  bool result;
                                  /* solium-disable-next-line security/no-inline-assembly */
                                  assembly {
                                      let x := mload(0x40)   // "Allocate" memory for output (0x40 is where "free memory" pointer is stored by convention)
                                      let d := add(data, 32) // First 32 bytes are the padded length of data, so exclude that
                                      result := call(
                                          sub(gas(), 34710),   // 34710 is the value that solidity is currently emitting
                                                             // It includes callGas (700) + callVeryLow (3, to pay for SUB) + callValueTransferGas (9000) +
                                                             // callNewAccountGas (25000, in case the destination address does not exist and needs creating)
                                          destination,
                                          value,
                                          d,
                                          dataLength,        // Size of the input (in bytes) - this is what fixes the padding problem
                                          x,
                                          0                  // Output is ignored, therefore the output size is zero
                                      )
                                  }
                                  return result;
                              }
                              /**
                               * Adds a new transaction to the transaction mapping, if transaction does not exist yet.
                               *
                               * @param  destination  Transaction target address.
                               * @param  value        Transaction ether value.
                               * @param  data         Transaction data payload.
                               * @return              Transaction ID.
                               */
                              function addTransaction(
                                  address destination,
                                  uint256 value,
                                  bytes memory data
                              )
                                  internal
                                  notNull(destination)
                                  returns (uint256)
                              {
                                  uint256 transactionId = transactionCount;
                                  transactions[transactionId] = Transaction({
                                      destination: destination,
                                      value: value,
                                      data: data,
                                      executed: false
                                  });
                                  transactionCount += 1;
                                  emit Submission(transactionId);
                                  return transactionId;
                              }
                          }pragma solidity 0.6.12;
                          contract MultiSigLibEIP712 {
                              /***********************************|
                            |             Constants             |
                            |__________________________________*/
                              // EIP712Domain
                              string public constant EIP712_DOMAIN_NAME = "MultiSig";
                              string public constant EIP712_DOMAIN_VERSION = "v1";
                              // EIP712Domain Separator
                              bytes32 public EIP712_DOMAIN_SEPARATOR;
                              // SUBMIT_TRANSACTION_TYPE_HASH = keccak256("submitTransaction(uint256 transactionId,address destination,uint256 value,bytes data)");
                              bytes32 public constant SUBMIT_TRANSACTION_TYPE_HASH = 0x2c78e27c3bb2592e67e8d37ad1a95bfccd188e77557c22593b1af0b920a08295;
                              // CONFIRM_TRANSACTION_TYPE_HASH = keccak256("confirmTransaction(uint256 transactionId)");
                              bytes32 public constant CONFIRM_TRANSACTION_TYPE_HASH = 0x3e96bdc38d4133bc81813a187b2d41bc74332643ce7dbe82c7d94ead8366a65f;
                              constructor() public {
                                  EIP712_DOMAIN_SEPARATOR = keccak256(
                                      abi.encode(
                                          keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                                          keccak256(bytes(EIP712_DOMAIN_NAME)),
                                          keccak256(bytes(EIP712_DOMAIN_VERSION)),
                                          getChainID(),
                                          address(this)
                                      )
                                  );
                              }
                              /**
                              * @dev Return `chainId`
                              */
                              function getChainID() internal pure returns (uint) {
                                  uint chainId;
                                  assembly {
                                      chainId := chainid()
                                  }
                                  return chainId;
                              }
                          }
                          pragma solidity 0.6.12;
                          import "./MultiSig.sol";
                          contract MiningTreasury is MultiSig {
                              constructor (
                                  address[] memory _owners,
                                  uint256 _required
                              )
                                  public
                                  MultiSig(_owners, _required)
                              {
                              }
                          }pragma solidity 0.6.12;
                          import "./MultiSig.sol";
                          // File: contracts/external/multisig/DelayedMultiSig.sol
                          /**
                           * @title DelayedMultiSig
                           * @author dYdX
                           *
                           * Multi-Signature Wallet with delay in execution.
                           * Allows multiple parties to execute a transaction after a time lock has passed.
                           * Adapted from Amir Bandeali's MultiSigWalletWithTimeLock contract.
                           * Logic Changes:
                           *  - Only owners can execute transactions
                           *  - Require that each transaction succeeds
                           *  - Added function to execute multiple transactions within the same Ethereum transaction
                           */
                          contract DelayedMultiSig is
                              MultiSig
                          {
                              // ============ Events ============
                              event ConfirmationTimeSet(uint256 indexed transactionId, uint256 confirmationTime);
                              event TimeLockChange(uint32 secondsTimeLocked);
                              // ============ Storage ============
                              uint32 public secondsTimeLocked;
                              mapping (uint256 => uint256) public confirmationTimes;
                              // ============ Modifiers ============
                              modifier notFullyConfirmed(
                                  uint256 transactionId
                              ) {
                                  require(
                                      !isConfirmed(transactionId),
                                      "TX_FULLY_CONFIRMED"
                                  );
                                  _;
                              }
                              modifier fullyConfirmed(
                                  uint256 transactionId
                              ) {
                                  require(
                                      isConfirmed(transactionId),
                                      "TX_NOT_FULLY_CONFIRMED"
                                  );
                                  _;
                              }
                              modifier pastTimeLock(
                                  uint256 transactionId
                              ) virtual {
                                  require(
                                      block.timestamp >= confirmationTimes[transactionId] + secondsTimeLocked,
                                      "TIME_LOCK_INCOMPLETE"
                                  );
                                  _;
                              }
                              // ============ Constructor ============
                              /**
                               * Contract constructor sets initial owners, required number of confirmations, and time lock.
                               *
                               * @param  _owners             List of initial owners.
                               * @param  _required           Number of required confirmations.
                               * @param  _secondsTimeLocked  Duration needed after a transaction is confirmed and before it
                               *                             becomes executable, in seconds.
                               */
                              constructor (
                                  address[] memory _owners,
                                  uint256 _required,
                                  uint32 _secondsTimeLocked
                              )
                                  public
                                  MultiSig(_owners, _required)
                              {
                                  secondsTimeLocked = _secondsTimeLocked;
                              }
                              // ============ Wallet-Only Functions ============
                              /**
                               * Changes the duration of the time lock for transactions.
                               *
                               * @param  _secondsTimeLocked  Duration needed after a transaction is confirmed and before it
                               *                             becomes executable, in seconds.
                               */
                              function changeTimeLock(
                                  uint32 _secondsTimeLocked
                              )
                                  public
                                  onlyWallet
                              {
                                  secondsTimeLocked = _secondsTimeLocked;
                                  emit TimeLockChange(_secondsTimeLocked);
                              }
                              // ============ Owner Functions ============
                              /**
                               * Allows an owner to confirm a transaction.
                               * Overrides the function in MultiSig.
                               *
                               * @param  transactionId  Transaction ID.
                               */
                              function confirmTransaction(
                                  uint256 transactionId
                              )
                                  public
                                  override
                                  ownerExists(msg.sender)
                                  transactionExists(transactionId)
                                  notConfirmed(transactionId, msg.sender)
                                  notFullyConfirmed(transactionId)
                              {
                                  confirmations[transactionId][msg.sender] = true;
                                  emit Confirmation(msg.sender, transactionId);
                                  if (isConfirmed(transactionId)) {
                                      setConfirmationTime(transactionId, block.timestamp);
                                  }
                              }
                              /**
                               * Allows an owner to confirm a transaction via meta transaction.
                               * Overrides the function in MultiSig.
                               *
                               * @param  signer           Signer of the meta transaction.
                               * @param  transactionId    Transaction ID.
                               * @param  sig              Signature.
                               */
                              function confirmTransaction(
                                  address signer,
                                  uint256 transactionId,
                                  bytes memory sig
                              )
                                  public
                                  override
                                  ownerExists(signer)
                                  transactionExists(transactionId)
                                  notConfirmed(transactionId, signer)
                                  notFullyConfirmed(transactionId)
                              {
                                  // CONFIRM_TRANSACTION_TYPE_HASH = keccak256("confirmTransaction(uint256 transactionId)");
                                  bytes32 EIP712SignDigest = keccak256(
                                      abi.encodePacked(
                                          bytes1(0x19),
                                          bytes1(0x01),
                                          EIP712_DOMAIN_SEPARATOR,
                                          keccak256(
                                              abi.encode(
                                                  CONFIRM_TRANSACTION_TYPE_HASH,
                                                  transactionId
                                              )
                                          )
                                      )
                                  );
                                  validateSignature(signer, EIP712SignDigest, sig);
                                  confirmations[transactionId][signer] = true;
                                  emit Confirmation(signer, transactionId);
                                  if (isConfirmed(transactionId)) {
                                      setConfirmationTime(transactionId, block.timestamp);
                                  }
                              }
                              /**
                               * Allows an owner to execute a confirmed transaction.
                               * Overrides the function in MultiSig.
                               *
                               * @param  transactionId  Transaction ID.
                               */
                              function executeTransaction(
                                  uint256 transactionId
                              )
                                  public
                                  override
                                  ownerExists(msg.sender)
                                  notExecuted(transactionId)
                                  fullyConfirmed(transactionId)
                                  pastTimeLock(transactionId)
                              {
                                  Transaction storage txn = transactions[transactionId];
                                  txn.executed = true;
                                  bool success = externalCall(
                                      txn.destination,
                                      txn.value,
                                      txn.data.length,
                                      txn.data
                                  );
                                  require(
                                      success,
                                      "TX_REVERTED"
                                  );
                                  emit Execution(transactionId);
                              }
                              /**
                               * Allows an owner to execute multiple confirmed transactions.
                               *
                               * @param  transactionIds  List of transaction IDs.
                               */
                              function executeMultipleTransactions(
                                  uint256[] memory transactionIds
                              )
                                  public
                                  ownerExists(msg.sender)
                              {
                                  for (uint256 i = 0; i < transactionIds.length; i++) {
                                      executeTransaction(transactionIds[i]);
                                  }
                              }
                              // ============ Helper Functions ============
                              /**
                               * Sets the time of when a submission first passed.
                               */
                              function setConfirmationTime(
                                  uint256 transactionId,
                                  uint256 confirmationTime
                              )
                                  internal
                              {
                                  confirmationTimes[transactionId] = confirmationTime;
                                  emit ConfirmationTimeSet(transactionId, confirmationTime);
                              }
                          }pragma solidity 0.6.12;
                          import "./DelayedMultiSig.sol";
                          // File: contracts/external/multisig/PartiallyDelayedMultiSig.sol
                          /**
                           * @title PartiallyDelayedMultiSig
                           * @author dYdX
                           *
                           * Multi-Signature Wallet with delay in execution except for some function selectors.
                           */
                          contract PartiallyDelayedMultiSig is
                              DelayedMultiSig
                          {
                              // ============ Events ============
                              event SelectorSet(address destination, bytes4 selector, bool approved);
                              // ============ Constants ============
                              bytes4 constant internal BYTES_ZERO = bytes4(0x0);
                              // ============ Storage ============
                              // destination => function selector => can bypass timelock
                              mapping (address => mapping (bytes4 => bool)) public instantData;
                              // ============ Modifiers ============
                              // Overrides old modifier that requires a timelock for every transaction
                              modifier pastTimeLock(
                                  uint256 transactionId
                              ) override {
                                  // if the function selector is not exempt from timelock, then require timelock
                                  require(
                                      block.timestamp >= confirmationTimes[transactionId] + secondsTimeLocked
                                      || txCanBeExecutedInstantly(transactionId),
                                      "TIME_LOCK_INCOMPLETE"
                                  );
                                  _;
                              }
                              // ============ Constructor ============
                              /**
                               * Contract constructor sets initial owners, required number of confirmations, and time lock.
                               *
                               * @param  _owners               List of initial owners.
                               * @param  _required             Number of required confirmations.
                               * @param  _secondsTimeLocked    Duration needed after a transaction is confirmed and before it
                               *                               becomes executable, in seconds.
                               * @param  _noDelayDestinations  List of destinations that correspond with the selectors.
                               *                               Zero address allows the function selector to be used with any
                               *                               address.
                               * @param  _noDelaySelectors     All function selectors that do not require a delay to execute.
                               *                               Fallback function is 0x00000000.
                               */
                              constructor (
                                  address[] memory _owners,
                                  uint256 _required,
                                  uint32 _secondsTimeLocked,
                                  address[] memory _noDelayDestinations,
                                  bytes4[] memory _noDelaySelectors
                              )
                                  public
                                  DelayedMultiSig(_owners, _required, _secondsTimeLocked)
                              {
                                  require(
                                      _noDelayDestinations.length == _noDelaySelectors.length,
                                      "ADDRESS_AND_SELECTOR_MISMATCH"
                                  );
                                  for (uint256 i = 0; i < _noDelaySelectors.length; i++) {
                                      address destination = _noDelayDestinations[i];
                                      bytes4 selector = _noDelaySelectors[i];
                                      instantData[destination][selector] = true;
                                      emit SelectorSet(destination, selector, true);
                                  }
                              }
                              // ============ Wallet-Only Functions ============
                              /**
                               * Adds or removes functions that can be executed instantly. Transaction must be sent by wallet.
                               *
                               * @param  destination  Destination address of function. Zero address allows the function to be
                               *                      sent to any address.
                               * @param  selector     4-byte selector of the function. Fallback function is 0x00000000.
                               * @param  approved     True if adding approval, false if removing approval.
                               */
                              function setSelector(
                                  address destination,
                                  bytes4 selector,
                                  bool approved
                              )
                                  public
                                  onlyWallet
                              {
                                  instantData[destination][selector] = approved;
                                  emit SelectorSet(destination, selector, approved);
                              }
                              // ============ Helper Functions ============
                              /**
                               * Returns true if transaction can be executed instantly (without timelock).
                               */
                              function txCanBeExecutedInstantly(
                                  uint256 transactionId
                              )
                                  internal
                                  view
                                  returns (bool)
                              {
                                  // get transaction from storage
                                  Transaction memory txn = transactions[transactionId];
                                  address dest = txn.destination;
                                  bytes memory data = txn.data;
                                  // fallback function
                                  if (data.length == 0) {
                                      return selectorCanBeExecutedInstantly(dest, BYTES_ZERO);
                                  }
                                  // invalid function selector
                                  if (data.length < 4) {
                                      return false;
                                  }
                                  // check first four bytes (function selector)
                                  bytes32 rawData;
                                  /* solium-disable-next-line security/no-inline-assembly */
                                  assembly {
                                      rawData := mload(add(data, 32))
                                  }
                                  bytes4 selector = bytes4(rawData);
                                  return selectorCanBeExecutedInstantly(dest, selector);
                              }
                              /**
                               * Function selector is in instantData for address dest (or for address zero).
                               */
                              function selectorCanBeExecutedInstantly(
                                  address destination,
                                  bytes4 selector
                              )
                                  internal
                                  view
                                  returns (bool)
                              {
                                  return instantData[destination][selector]
                                      || instantData[ADDRESS_ZERO][selector];
                              }
                          }pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "./LibOrder.sol";
                          import "../../utils/LibBytes.sol";
                          contract LibDecoder {
                              using LibBytes for bytes;
                              function decodeFillOrder(bytes memory data) internal pure returns(LibOrder.Order memory order, uint256 takerFillAmount, bytes memory mmSignature) {
                                  require(
                                      data.length > 800,
                                      "LibDecoder: LENGTH_LESS_800"
                                  );
                                  // compare method_id
                                  // 0x64a3bc15 is fillOrKillOrder's method id.
                                  require(
                                      data.readBytes4(0) == 0x64a3bc15,
                                      "LibDecoder: WRONG_METHOD_ID"
                                  );
                                  
                                  bytes memory dataSlice;
                                  assembly {
                                      dataSlice := add(data, 4)
                                  }
                                  return abi.decode(dataSlice, (LibOrder.Order, uint256, bytes));
                              }
                              function decodeMmSignature(bytes memory signature) internal pure returns(uint8 v, bytes32 r, bytes32 s) {
                                  v = uint8(signature[0]);
                                  r = signature.readBytes32(1);
                                  s = signature.readBytes32(33);
                                  return (v, r, s);
                              }
                              function decodeUserSignatureWithoutSign(bytes memory signature) internal pure returns(address receiver) {
                                  require(
                                      signature.length == 85 || signature.length == 86,
                                      "LibDecoder: LENGTH_85_REQUIRED"
                                  );
                                  receiver = signature.readAddress(65);
                                  return receiver;
                              }
                              function decodeUserSignature(bytes memory signature) internal pure returns(uint8 v, bytes32 r, bytes32 s, address receiver) {
                                  receiver = decodeUserSignatureWithoutSign(signature);
                                  v = uint8(signature[0]);
                                  r = signature.readBytes32(1);
                                  s = signature.readBytes32(33);
                                  return (v, r, s, receiver);
                              }
                              function decodeERC20Asset(bytes memory assetData) internal pure returns(address) {
                                  require(
                                      assetData.length == 36,
                                      "LibDecoder: LENGTH_36_REQUIRED"
                                  );
                                  return assetData.readAddress(16);
                              }
                          }/*
                            Copyright 2018 ZeroEx Intl.
                            Licensed under the Apache License, Version 2.0 (the "License");
                            you may not use this file except in compliance with the License.
                            You may obtain a copy of the License at
                              http://www.apache.org/licenses/LICENSE-2.0
                            Unless required by applicable law or agreed to in writing, software
                            distributed under the License is distributed on an "AS IS" BASIS,
                            WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                            See the License for the specific language governing permissions and
                            limitations under the License.
                          */
                          pragma solidity ^0.6.0;
                          import "./LibEIP712.sol";
                          contract LibOrder is
                              LibEIP712
                          {
                              // Hash for the EIP712 Order Schema
                              bytes32 constant internal EIP712_ORDER_SCHEMA_HASH = keccak256(abi.encodePacked(
                                  "Order(",
                                  "address makerAddress,",
                                  "address takerAddress,",
                                  "address feeRecipientAddress,",
                                  "address senderAddress,",
                                  "uint256 makerAssetAmount,",
                                  "uint256 takerAssetAmount,",
                                  "uint256 makerFee,",
                                  "uint256 takerFee,",
                                  "uint256 expirationTimeSeconds,",
                                  "uint256 salt,",
                                  "bytes makerAssetData,",
                                  "bytes takerAssetData",
                                  ")"
                              ));
                              // A valid order remains fillable until it is expired, fully filled, or cancelled.
                              // An order's state is unaffected by external factors, like account balances.
                              enum OrderStatus {
                                  INVALID,                     // Default value
                                  INVALID_MAKER_ASSET_AMOUNT,  // Order does not have a valid maker asset amount
                                  INVALID_TAKER_ASSET_AMOUNT,  // Order does not have a valid taker asset amount
                                  FILLABLE,                    // Order is fillable
                                  EXPIRED,                     // Order has already expired
                                  FULLY_FILLED,                // Order is fully filled
                                  CANCELLED                    // Order has been cancelled
                              }
                              // solhint-disable max-line-length
                              struct Order {
                                  address makerAddress;           // Address that created the order.      
                                  address takerAddress;           // Address that is allowed to fill the order. If set to 0, any address is allowed to fill the order.          
                                  address feeRecipientAddress;    // Address that will recieve fees when order is filled.      
                                  address senderAddress;          // Address that is allowed to call Exchange contract methods that affect this order. If set to 0, any address is allowed to call these methods.
                                  uint256 makerAssetAmount;       // Amount of makerAsset being offered by maker. Must be greater than 0.        
                                  uint256 takerAssetAmount;       // Amount of takerAsset being bid on by maker. Must be greater than 0.        
                                  uint256 makerFee;               // Amount of ZRX paid to feeRecipient by maker when order is filled. If set to 0, no transfer of ZRX from maker to feeRecipient will be attempted.
                                  uint256 takerFee;               // Amount of ZRX paid to feeRecipient by taker when order is filled. If set to 0, no transfer of ZRX from taker to feeRecipient will be attempted.
                                  uint256 expirationTimeSeconds;  // Timestamp in seconds at which order expires.          
                                  uint256 salt;                   // Arbitrary number to facilitate uniqueness of the order's hash.     
                                  bytes makerAssetData;           // Encoded data that can be decoded by a specified proxy contract when transferring makerAsset. The last byte references the id of this proxy.
                                  bytes takerAssetData;           // Encoded data that can be decoded by a specified proxy contract when transferring takerAsset. The last byte references the id of this proxy.
                              }
                              // solhint-enable max-line-length
                              struct OrderInfo {
                                  uint8 orderStatus;                    // Status that describes order's validity and fillability.
                                  bytes32 orderHash;                    // EIP712 hash of the order (see LibOrder.getOrderHash).
                                  uint256 orderTakerAssetFilledAmount;  // Amount of order that has already been filled.
                              }
                              /// @dev Calculates Keccak-256 hash of the order.
                              /// @param order The order structure.
                              /// @return orderHash Keccak-256 EIP712 hash of the order.
                              function getOrderHash(Order memory order)
                                  internal
                                  view
                                  returns (bytes32 orderHash)
                              {
                                  orderHash = hashEIP712Message(hashOrder(order));
                                  return orderHash;
                              }
                              /// @dev Calculates EIP712 hash of the order.
                              /// @param order The order structure.
                              /// @return result EIP712 hash of the order.
                              function hashOrder(Order memory order)
                                  internal
                                  pure
                                  returns (bytes32 result)
                              {
                                  bytes32 schemaHash = EIP712_ORDER_SCHEMA_HASH;
                                  bytes32 makerAssetDataHash = keccak256(order.makerAssetData);
                                  bytes32 takerAssetDataHash = keccak256(order.takerAssetData);
                                  // Assembly for more efficiently computing:
                                  // keccak256(abi.encodePacked(
                                  //     EIP712_ORDER_SCHEMA_HASH,
                                  //     bytes32(order.makerAddress),
                                  //     bytes32(order.takerAddress),
                                  //     bytes32(order.feeRecipientAddress),
                                  //     bytes32(order.senderAddress),
                                  //     order.makerAssetAmount,
                                  //     order.takerAssetAmount,
                                  //     order.makerFee,
                                  //     order.takerFee,
                                  //     order.expirationTimeSeconds,
                                  //     order.salt,
                                  //     keccak256(order.makerAssetData),
                                  //     keccak256(order.takerAssetData)
                                  // ));
                                  assembly {
                                      // Calculate memory addresses that will be swapped out before hashing
                                      let pos1 := sub(order, 32)
                                      let pos2 := add(order, 320)
                                      let pos3 := add(order, 352)
                                      // Backup
                                      let temp1 := mload(pos1)
                                      let temp2 := mload(pos2)
                                      let temp3 := mload(pos3)
                                      
                                      // Hash in place
                                      mstore(pos1, schemaHash)
                                      mstore(pos2, makerAssetDataHash)
                                      mstore(pos3, takerAssetDataHash)
                                      result := keccak256(pos1, 416)
                                      
                                      // Restore
                                      mstore(pos1, temp1)
                                      mstore(pos2, temp2)
                                      mstore(pos3, temp3)
                                  }
                                  return result;
                              }
                          }/*
                            Copyright 2018 ZeroEx Intl.
                            Licensed under the Apache License, Version 2.0 (the "License");
                            you may not use this file except in compliance with the License.
                            You may obtain a copy of the License at
                              http://www.apache.org/licenses/LICENSE-2.0
                            Unless required by applicable law or agreed to in writing, software
                            distributed under the License is distributed on an "AS IS" BASIS,
                            WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                            See the License for the specific language governing permissions and
                            limitations under the License.
                          */
                          pragma solidity ^0.6.0;
                          contract LibEIP712 {
                              // EIP191 header for EIP712 prefix
                              string constant internal EIP191_HEADER = "\\x19\\x01";
                              // EIP712 Domain Name value
                              string constant internal EIP712_DOMAIN_NAME = "0x Protocol";
                              // EIP712 Domain Version value
                              string constant internal EIP712_DOMAIN_VERSION = "2";
                              // Hash of the EIP712 Domain Separator Schema
                              bytes32 constant internal EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH = keccak256(abi.encodePacked(
                                  "EIP712Domain(",
                                  "string name,",
                                  "string version,",
                                  "address verifyingContract",
                                  ")"
                              ));
                              // Hash of the EIP712 Domain Separator data
                              // solhint-disable-next-line var-name-mixedcase
                              bytes32 public EIP712_DOMAIN_HASH;
                              constructor ()
                                  public
                              {
                                  EIP712_DOMAIN_HASH = keccak256(abi.encodePacked(
                                      EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
                                      keccak256(bytes(EIP712_DOMAIN_NAME)),
                                      keccak256(bytes(EIP712_DOMAIN_VERSION)),
                                      bytes12(0),
                                      address(this)
                                  ));
                              }
                              /// @dev Calculates EIP712 encoding for a hash struct in this EIP712 Domain.
                              /// @param hashStruct The EIP712 hash struct.
                              /// @return result EIP712 hash applied to this EIP712 Domain.
                              function hashEIP712Message(bytes32 hashStruct)
                                  internal
                                  view
                                  returns (bytes32 result)
                              {
                                  bytes32 eip712DomainHash = EIP712_DOMAIN_HASH;
                                  // Assembly for more efficient computing:
                                  // keccak256(abi.encodePacked(
                                  //     EIP191_HEADER,
                                  //     EIP712_DOMAIN_HASH,
                                  //     hashStruct    
                                  // ));
                                  assembly {
                                      // Load free memory pointer
                                      let memPtr := mload(64)
                                      mstore(memPtr, 0x1901000000000000000000000000000000000000000000000000000000000000)  // EIP191 header
                                      mstore(add(memPtr, 2), eip712DomainHash)                                            // EIP712 domain hash
                                      mstore(add(memPtr, 34), hashStruct)                                                 // Hash of struct
                                      // Compute hash
                                      result := keccak256(memPtr, 66)
                                  }
                                  return result;
                              }
                          }pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "@openzeppelin/contracts/math/SafeMath.sol";
                          import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
                          import "@openzeppelin/contracts/utils/Address.sol";
                          import "./pmm/0xLibs/LibOrder.sol";
                          import "./pmm/0xLibs/LibDecoder.sol";
                          import "./pmm/0xLibs/LibEncoder.sol";
                          import "./interfaces/ISpender.sol";
                          import "./interfaces/IZeroExchange.sol";
                          import "./interfaces/IWeth.sol";
                          import "./interfaces/IPMM.sol";
                          import "./interfaces/IPermanentStorage.sol";
                          import "./interfaces/IERC1271Wallet.sol";
                          contract PMM is
                              ReentrancyGuard,
                              IPMM,
                              LibOrder,
                              LibDecoder,
                              LibEncoder
                          {
                              using SafeMath for uint256;
                              using SafeERC20 for IERC20;
                              using Address for address;
                              // Constants do not have storage slot.
                              string public constant version = "5.0.0";
                              uint256 private constant MAX_UINT = 2**256 - 1;
                              string public constant SOURCE = "0x v2";
                              uint256 private constant BPS_MAX = 10000;
                              bytes4 constant internal ERC1271_MAGICVALUE_BYTES32 = 0x1626ba7e;  // bytes4(keccak256("isValidSignature(bytes32,bytes)"))
                              address public immutable userProxy;
                              ISpender public immutable spender;
                              IPermanentStorage public immutable permStorage;
                              IZeroExchange public immutable zeroExchange;
                              address public immutable zxERC20Proxy;
                              // Below are the variables which consume storage slots.
                              address public operator;
                              struct TradeInfo {
                                  address user;
                                  address receiver;
                                  uint16 feeFactor;
                                  address makerAssetAddr;
                                  address takerAssetAddr;
                                  bytes32 transactionHash;
                                  bytes32 orderHash;
                              }
                              // events
                              event FillOrder(
                                  string source,
                                  bytes32 indexed transactionHash,
                                  bytes32 indexed orderHash,
                                  address indexed userAddr,
                                  address takerAssetAddr,
                                  uint256 takerAssetAmount,
                                  address makerAddr,
                                  address makerAssetAddr,
                                  uint256 makerAssetAmount,
                                  address receiverAddr,
                                  uint256 settleAmount,
                                  uint16 feeFactor
                              );
                              receive() external payable {}
                              /************************************************************
                              *          Access control and ownership management          *
                              *************************************************************/
                              modifier onlyOperator {
                                  require(operator == msg.sender, "PMM: not operator");
                                  _;
                              }
                              modifier onlyUserProxy() {
                                  require(address(userProxy) == msg.sender, "PMM: not the UserProxy contract");
                                  _;
                              }
                              function transferOwnership(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "AMMWrapper: operator can not be zero address");
                                  operator = _newOperator;
                              }
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              constructor (address _operator, address _userProxy, ISpender _spender, IPermanentStorage _permStorage, IZeroExchange _zeroExchange, address _zxERC20Proxy) public {
                                  operator = _operator;
                                  userProxy = _userProxy;
                                  spender = _spender;
                                  permStorage = _permStorage;
                                  zeroExchange = _zeroExchange;
                                  zxERC20Proxy = _zxERC20Proxy;
                                  // This constant follows ZX_EXCHANGE address
                                  EIP712_DOMAIN_HASH = keccak256(
                                      abi.encodePacked(
                                          EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH,
                                          keccak256(bytes(EIP712_DOMAIN_NAME)),
                                          keccak256(bytes(EIP712_DOMAIN_VERSION)),
                                          bytes12(0),
                                          address(_zeroExchange)
                                      )
                                  );
                              }
                              /************************************************************
                              *           Management functions for Operator               *
                              *************************************************************/
                              /**
                               * @dev approve spender to transfer tokens from this contract. This is used to collect fee.
                               */
                              function setAllowance(address[] calldata _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, MAX_UINT);
                                  }
                              }
                              function closeAllowance(address[] calldata _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, 0);
                                  }
                              }
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              function fill(
                                  uint256 userSalt,
                                  bytes memory data,
                                  bytes memory userSignature
                              )
                                  override
                                  public
                                  payable
                                  onlyUserProxy
                                  nonReentrant
                                  returns (uint256)
                              {
                                  // decode & assert
                                  (LibOrder.Order memory order,
                                  TradeInfo memory tradeInfo) = _assertTransaction(userSalt, data, userSignature);
                                  // Deposit to WETH if taker asset is ETH, else transfer from user
                                  IWETH weth = IWETH(permStorage.wethAddr());
                                  if (address(weth) == tradeInfo.takerAssetAddr) {
                                      require(
                                          msg.value == order.takerAssetAmount,
                                          "PMM: insufficient ETH"
                                      );
                                      weth.deposit{value: msg.value}();
                                  } else {
                                      spender.spendFromUser(tradeInfo.user, tradeInfo.takerAssetAddr, order.takerAssetAmount);
                                  }
                                  IERC20(tradeInfo.takerAssetAddr).safeIncreaseAllowance(zxERC20Proxy, order.takerAssetAmount);
                                  // send tx to 0x
                                  zeroExchange.executeTransaction(
                                      userSalt,
                                      address(this),
                                      data,
                                      ""
                                  );
                                  // settle token/ETH to user
                                  uint256 settleAmount = _settle(weth, tradeInfo.receiver, tradeInfo.makerAssetAddr, order.makerAssetAmount, tradeInfo.feeFactor);
                                  IERC20(tradeInfo.takerAssetAddr).safeApprove(zxERC20Proxy, 0);
                                  emit FillOrder(
                                      SOURCE,
                                      tradeInfo.transactionHash,
                                      tradeInfo.orderHash,
                                      tradeInfo.user,
                                      tradeInfo.takerAssetAddr,
                                      order.takerAssetAmount,
                                      order.makerAddress,
                                      tradeInfo.makerAssetAddr,
                                      order.makerAssetAmount,
                                      tradeInfo.receiver,
                                      settleAmount,
                                      tradeInfo.feeFactor
                                  );
                                  return settleAmount;
                              }
                              /**
                               * @dev internal function of `fill`.
                               * It decodes and validates transaction data.
                               */
                              function _assertTransaction(
                                  uint256 userSalt,
                                  bytes memory data,
                                  bytes memory userSignature
                              )
                                  internal
                                  view
                                  returns(
                                      LibOrder.Order memory order,
                                      TradeInfo memory tradeInfo
                                  )
                              {
                                  // decode fillOrder data
                                  uint256 takerFillAmount;
                                  bytes memory mmSignature;
                                  (order, takerFillAmount, mmSignature) = decodeFillOrder(data);
                                  require(
                                      order.takerAddress == address(this),
                                      "PMM: incorrect taker"
                                  );
                                  require(
                                      order.takerAssetAmount == takerFillAmount,
                                      "PMM: incorrect fill amount"
                                  );
                                  // generate transactionHash
                                  tradeInfo.transactionHash = encodeTransactionHash(
                                      userSalt,
                                      address(this),
                                      data
                                  );
                                  tradeInfo.orderHash = getOrderHash(order);
                                  tradeInfo.feeFactor = uint16(order.salt);
                                  tradeInfo.receiver = decodeUserSignatureWithoutSign(userSignature);
                                  tradeInfo.user = _ecrecoverAddress(tradeInfo.transactionHash, userSignature);
                                  if (tradeInfo.user != order.feeRecipientAddress) {
                                      require(
                                          order.feeRecipientAddress.isContract(),
                                          "PMM: invalid contract address"
                                      );
                                      // isValidSignature() should return magic value: bytes4(keccak256("isValidSignature(bytes32,bytes)"))
                                      require(
                                          ERC1271_MAGICVALUE_BYTES32 == IERC1271Wallet(order.feeRecipientAddress)
                                              .isValidSignature(
                                                  tradeInfo.transactionHash,
                                                  userSignature
                                              ),
                                          "PMM: invalid ERC1271 signer"
                                      );
                                      tradeInfo.user = order.feeRecipientAddress;
                                  }
                                  require(
                                      tradeInfo.feeFactor < BPS_MAX,
                                      "PMM: invalid fee factor"
                                  );
                                  require(
                                      tradeInfo.receiver != address(0),
                                      "PMM: invalid receiver"
                                  );
                                  // decode asset
                                  // just support ERC20
                                  tradeInfo.makerAssetAddr = decodeERC20Asset(order.makerAssetData);
                                  tradeInfo.takerAssetAddr = decodeERC20Asset(order.takerAssetData);
                                  return (
                                      order,
                                      tradeInfo
                                  );        
                              }
                              // settle
                              function _settle(IWETH weth, address receiver, address makerAssetAddr, uint256 makerAssetAmount, uint16 feeFactor) internal returns(uint256) {
                                  uint256 settleAmount = makerAssetAmount;
                                  if (feeFactor > 0) {
                                      // settleAmount = settleAmount * (10000 - feeFactor) / 10000
                                      settleAmount = settleAmount.mul((BPS_MAX).sub(feeFactor)).div(BPS_MAX);
                                  }
                                  if (makerAssetAddr == address(weth)){
                                      weth.withdraw(settleAmount);
                                      payable(receiver).transfer(settleAmount);
                                  } else {
                                      IERC20(makerAssetAddr).safeTransfer(receiver, settleAmount);
                                  }
                                  return settleAmount;
                              }
                              function _ecrecoverAddress(bytes32 transactionHash, bytes memory signature) internal pure returns (address){
                                  (uint8 v, bytes32 r, bytes32 s, address receiver) = decodeUserSignature(signature);
                                  return ecrecover(
                                      keccak256(
                                          abi.encodePacked(
                                              transactionHash,
                                              receiver
                                          )),
                                      v, r, s
                                  );
                              }
                          }
                          pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "./LibEIP712.sol";
                          contract LibEncoder is
                              LibEIP712
                          {
                              // Hash for the EIP712 ZeroEx Transaction Schema
                              bytes32 constant internal EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH = keccak256(
                                  abi.encodePacked(
                                  "ZeroExTransaction(",
                                  "uint256 salt,",
                                  "address signerAddress,",
                                  "bytes data",
                                  ")"
                              ));
                              function encodeTransactionHash(
                                  uint256 salt,
                                  address signerAddress,
                                  bytes memory data
                              )
                                  internal
                                  view 
                                  returns (bytes32 result)
                              {
                                  bytes32 schemaHash = EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH;
                                  bytes32 dataHash = keccak256(data);
                                  // Assembly for more efficiently computing:
                                  // keccak256(abi.encodePacked(
                                  //     EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
                                  //     salt,
                                  //     bytes32(signerAddress),
                                  //     keccak256(data)
                                  // ));
                                  assembly {
                                      // Load free memory pointer
                                      let memPtr := mload(64)
                                      mstore(memPtr, schemaHash)                                                               // hash of schema
                                      mstore(add(memPtr, 32), salt)                                                            // salt
                                      mstore(add(memPtr, 64), and(signerAddress, 0xffffffffffffffffffffffffffffffffffffffff))  // signerAddress
                                      mstore(add(memPtr, 96), dataHash)                                                        // hash of data
                                      // Compute hash
                                      result := keccak256(memPtr, 128)
                                  }
                                  result = hashEIP712Message(result);
                                  return result;
                              }
                          }/*
                            Copyright 2018 ZeroEx Intl.
                            Licensed under the Apache License, Version 2.0 (the "License");
                            you may not use this file except in compliance with the License.
                            You may obtain a copy of the License at
                              http://www.apache.org/licenses/LICENSE-2.0
                            Unless required by applicable law or agreed to in writing, software
                            distributed under the License is distributed on an "AS IS" BASIS,
                            WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
                            See the License for the specific language governing permissions and
                            limitations under the License.
                          */
                          pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          interface IZeroExchange {
                              function executeTransaction(
                                  uint256 salt,
                                  address signerAddress,
                                  bytes calldata data,
                                  bytes calldata signature
                              ) external;
                          }
                          pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "../pmm/0xLibs/LibOrder.sol";
                          import "./ISetAllowance.sol";
                          interface IPMM is ISetAllowance {
                              function fill(
                                  uint256 userSalt,
                                  bytes memory data,
                                  bytes memory userSignature
                              ) external payable returns (uint256);
                          }// SPDX-License-Identifier: MIT
                          pragma solidity ^0.6.5;
                          import "../interfaces/IPermanentStorage.sol";
                          import "../utils/lib_storage/PSStorage.sol";
                          contract PermanentStorageStub is IPermanentStorage {
                              // Supported Curve pools
                              address public constant CURVE_COMPOUND_POOL = 0xA2B47E3D5c44877cca798226B7B8118F9BFb7A56;
                              address public constant CURVE_USDT_POOL = 0x52EA46506B9CC5Ef470C5bf89f17Dc28bB35D85C;
                              address public constant CURVE_Y_POOL = 0x45F783CCE6B7FF23B2ab2D70e416cdb7D6055f51;
                              address public constant CURVE_3_POOL = 0xbEbc44782C7dB0a1A60Cb6fe97d0b483032FF1C7;
                              address public constant CURVE_sUSD_POOL = 0xA5407eAE9Ba41422680e2e00537571bcC53efBfD;
                              address public constant CURVE_BUSD_POOL = 0x79a8C46DeA5aDa233ABaFFD40F3A0A2B1e5A4F27;
                              address public constant CURVE_renBTC_POOL = 0x93054188d876f558f4a66B2EF1d97d16eDf0895B;
                              address public constant CURVE_sBTC_POOL = 0x7fC77b5c7614E1533320Ea6DDc2Eb61fa00A9714;
                              address public constant CURVE_hBTC_POOL = 0x4CA9b3063Ec5866A4B82E437059D2C43d1be596F;
                              address public constant CURVE_sETH_POOL = 0xc5424B857f758E906013F3555Dad202e4bdB4567;
                              // Curve coins
                              address private constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant DAI = 0x6B175474E89094C44Da98b954EedeAC495271d0F;
                              address private constant USDC = 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
                              address private constant cDAI = 0x5d3a536E4D6DbD6114cc1Ead35777bAB948E3643;
                              address private constant cUSDC = 0x39AA39c021dfbaE8faC545936693aC917d5E7563;
                              address private constant USDT = 0xdAC17F958D2ee523a2206206994597C13D831ec7;
                              address private constant TUSD = 0x0000000000085d4780B73119b644AE5ecd22b376;
                              address private constant Y_POOL_yDAI = 0x16de59092dAE5CcF4A1E6439D611fd0653f0Bd01;
                              address private constant Y_POOL_yUSDC = 0xd6aD7a6750A7593E092a9B218d66C0A814a3436e;
                              address private constant Y_POOL_yUSDT = 0x83f798e925BcD4017Eb265844FDDAbb448f1707D;
                              address private constant Y_POOL_yTUSD = 0x73a052500105205d34Daf004eAb301916DA8190f;
                              address private constant sUSD = 0x57Ab1ec28D129707052df4dF418D58a2D46d5f51;
                              address private constant BUSD = 0x4Fabb145d64652a948d72533023f6E7A623C7C53;
                              address private constant BUSD_POOL_yDAI = 0xC2cB1040220768554cf699b0d863A3cd4324ce32;
                              address private constant BUSD_POOL_yUSDC = 0x26EA744E5B887E5205727f55dFBE8685e3b21951;
                              address private constant BUSD_POOL_yUSDT = 0xE6354ed5bC4b393a5Aad09f21c46E101e692d447;
                              address private constant BUSD_POOL_yBUSD = 0x04bC0Ab673d88aE9dbC9DA2380cB6B79C4BCa9aE;
                              address private constant renBTC = 0xEB4C2781e4ebA804CE9a9803C67d0893436bB27D;
                              address private constant wBTC = 0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599;
                              address private constant sBTC = 0xfE18be6b3Bd88A2D2A7f928d00292E7a9963CfC6;
                              address private constant hBTC = 0x0316EB71485b0Ab14103307bf65a021042c6d380;
                              address private constant sETH = 0x5e74C9036fb86BD7eCdcb084a0673EFc32eA31cb;
                              constructor() public {
                                  // register WETH address
                                  PSStorage.getStorage().wethAddr = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
                                  // register Compound pool
                                  // underlying_coins, exchange_underlying
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_COMPOUND_POOL][DAI] = 1;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_COMPOUND_POOL][USDC] = 2;
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_COMPOUND_POOL][cDAI] = 1;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_COMPOUND_POOL][cUSDC] = 2;
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_COMPOUND_POOL] = true; // support get_dx or get_dx_underlying for quoting
                                  // register USDT pool
                                  // underlying_coins, exchange_underlying
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_USDT_POOL][DAI] = 1;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_USDT_POOL][USDC] = 2;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_USDT_POOL][USDT] = 3;
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_USDT_POOL][cDAI] = 1;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_USDT_POOL][cUSDC] = 2;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_USDT_POOL][USDT] = 3;
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_USDT_POOL] = true;
                                  // register Y pool
                                  // underlying_coins, exchange_underlying
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_Y_POOL][DAI] = 1;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_Y_POOL][USDC] = 2;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_Y_POOL][USDT] = 3;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_Y_POOL][TUSD] = 4;
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_Y_POOL][Y_POOL_yDAI] = 1;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_Y_POOL][Y_POOL_yUSDC] = 2;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_Y_POOL][Y_POOL_yUSDT] = 3;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_Y_POOL][Y_POOL_yTUSD] = 4;
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_Y_POOL] = true;
                                  // register 3 pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_3_POOL][DAI] = 1;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_3_POOL][USDC] = 2;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_3_POOL][USDT] = 3;
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_3_POOL] = false; // only support get_dy and get_dy_underlying for exactly the same functionality
                                  // register sUSD pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sUSD_POOL][DAI] = 1;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sUSD_POOL][USDC] = 2;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sUSD_POOL][USDT] = 3;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sUSD_POOL][sUSD] = 4;
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_sUSD_POOL] = false;
                                  // register BUSD pool
                                  // underlying_coins, exchange_underlying
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_BUSD_POOL][DAI] = 1;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_BUSD_POOL][USDC] = 2;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_BUSD_POOL][USDT] = 3;
                                  AMMWrapperStorage.getStorage().curveTokenIndexes[CURVE_BUSD_POOL][BUSD] = 4;
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_BUSD_POOL][BUSD_POOL_yDAI] = 1;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_BUSD_POOL][BUSD_POOL_yUSDC] = 2;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_BUSD_POOL][BUSD_POOL_yUSDT] = 3;
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_BUSD_POOL][BUSD_POOL_yBUSD] = 4;
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_BUSD_POOL] = true;
                                  // register renBTC pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_renBTC_POOL][renBTC] = 1; // renBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_renBTC_POOL][wBTC] = 2; // wBTC
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_renBTC_POOL] = false;
                                  // register sBTC pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sBTC_POOL][renBTC] = 1; // renBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sBTC_POOL][wBTC] = 2; // wBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sBTC_POOL][sBTC] = 3; // sBTC
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_sBTC_POOL] = false;
                                  // register hBTC pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_hBTC_POOL][hBTC] = 1; // hBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_hBTC_POOL][wBTC] = 2; // wBTC
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_hBTC_POOL] = false;
                                  // register sETH pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sETH_POOL][ETH] = 1; // ETH
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sETH_POOL][sETH] = 2; // sETH
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_sETH_POOL] = false;
                              }
                              /************************************************************
                              *                     Getter functions                      *
                              *************************************************************/
                              function ammWrapperAddr() public view returns (address) {
                                  return PSStorage.getStorage().ammWrapperAddr;
                              }
                              function pmmAddr() public view returns (address) {
                                  return PSStorage.getStorage().pmmAddr;
                              }
                              function rfqAddr() public view returns (address) {
                                  return PSStorage.getStorage().rfqAddr;
                              }
                              function wethAddr() override external view returns (address) {
                                  return PSStorage.getStorage().wethAddr;
                              }
                              function getCurvePoolInfo(address _makerAddr, address _takerAssetAddr, address _makerAssetAddr) override external view returns (int128 takerAssetIndex, int128 makerAssetIndex, uint16 swapMethod, bool supportGetDx) {
                                  // underlying_coins
                                  int128 i = AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][_takerAssetAddr];
                                  int128 j = AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][_makerAssetAddr];
                                  supportGetDx = AMMWrapperStorage.getStorage().curveSupportGetDx[_makerAddr];
                                  swapMethod = 0;
                                  if (i != 0 && j != 0) {
                                      // in underlying_coins list
                                      takerAssetIndex = i;
                                      makerAssetIndex = j;
                                      // exchange_underlying
                                      swapMethod = 2;
                                  } else {
                                      // in coins list
                                      int128 iWrapped = AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][_takerAssetAddr];
                                      int128 jWrapped = AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][_makerAssetAddr];
                                      if (iWrapped != 0 && jWrapped != 0) {
                                          takerAssetIndex = iWrapped;
                                          makerAssetIndex = jWrapped;
                                          // exchange
                                          swapMethod = 1;
                                      } else {
                                          revert("PermanentStorage: invalid pair");
                                      }
                                  }
                                  return (takerAssetIndex, makerAssetIndex, swapMethod, supportGetDx);
                              }
                              function isTransactionSeen(bytes32 _transactionHash) override external view returns (bool) {
                                  return AMMWrapperStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isAMMTransactionSeen(bytes32 _transactionHash) override external view returns (bool) {
                                  return AMMWrapperStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isRFQTransactionSeen(bytes32 _transactionHash) override external view returns (bool) {
                                  return RFQStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isRelayerValid(address _relayer) override external view returns (bool) {
                                  return AMMWrapperStorage.getStorage().relayerValid[_relayer];
                              }
                              /************************************************************
                              *           Management functions for Operator               *
                              *************************************************************/
                              /// @dev Update AMMWrapper contract address.
                              function upgradeAMMWrapper(address _newAMMWrapper) external {
                                  PSStorage.getStorage().ammWrapperAddr = _newAMMWrapper;
                              }
                              /// @dev Update PMM contract address.
                              function upgradePMM(address _newPMM) external {
                                  PSStorage.getStorage().pmmAddr = _newPMM;
                              }
                              /// @dev Update RFQ contract address.
                              function upgradeRFQ(address _newRFQ) external {
                                  PSStorage.getStorage().rfqAddr = _newRFQ;
                              }
                              /// @dev Update WETH contract address.
                              function upgradeWETH(address _newWETH) external {
                                  PSStorage.getStorage().wethAddr = _newWETH;
                              }
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              function setCurvePoolInfo(address _makerAddr, address[] calldata _underlyingCoins, address[] calldata _coins, bool _supportGetDx) override external {
                                  int128 underlyingCoinsLength = int128(_underlyingCoins.length);
                                  for (int128 i = 0 ; i < underlyingCoinsLength; i++) {
                                      address assetAddr = _underlyingCoins[uint256(i)];
                                      // underlying coins for original DAI, USDC, TUSD
                                      AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][assetAddr] = i + 1;
                                  }
                                  int128 coinsLength = int128(_coins.length);
                                  for (int128 i = 0 ; i < coinsLength; i++) {
                                      address assetAddr = _coins[uint256(i)];
                                      // wrapped coins for cDAI, cUSDC, yDAI, yUSDC, yTUSD, yBUSD
                                      AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][assetAddr] = i + 1;
                                  }
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[_makerAddr] = _supportGetDx;
                              }
                              function setTransactionSeen(bytes32 _transactionHash) override external {
                                  require(!AMMWrapperStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  AMMWrapperStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setAMMTransactionSeen(bytes32 _transactionHash) override external {
                                  require(!AMMWrapperStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  AMMWrapperStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setRFQTransactionSeen(bytes32 _transactionHash) override external {
                                  require(!RFQStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  RFQStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setRelayersValid(address[] calldata _relayers, bool[] calldata _isValids) override external {
                                  require(_relayers.length == _isValids.length, "PermanentStorage: inputs length mismatch");
                                  for (uint256 i = 0; i < _relayers.length; i++) {
                                      AMMWrapperStorage.getStorage().relayerValid[_relayers[i]] = _isValids[i];
                                  }
                              }
                          }
                          pragma solidity ^0.6.5;
                          pragma experimental ABIEncoderV2;
                          library PSStorage {
                              bytes32 private constant STORAGE_SLOT = 0x92dd52b981a2dd69af37d8a3febca29ed6a974aede38ae66e4ef773173aba471;
                              struct Storage {
                                  address ammWrapperAddr;
                                  address pmmAddr;
                                  address wethAddr;
                                  address rfqAddr;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.storage.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly { stor_slot := slot }
                              }
                          }
                          library AMMWrapperStorage {
                              bytes32 private constant STORAGE_SLOT = 0xd38d862c9fa97c2fa857a46e08022d272a3579c114ca4f335f1e5fcb692c045e;
                              struct Storage {
                                  mapping(bytes32 => bool) transactionSeen;
                                  // curve pool => underlying token address => underlying token index
                                  mapping(address => mapping(address => int128)) curveTokenIndexes;
                                  mapping(address => bool) relayerValid;
                                  // 5.1.0 appended storage
                                  // curve pool => wrapped token address => wrapped token index
                                  mapping(address => mapping(address => int128)) curveWrappedTokenIndexes;
                                  mapping(address => bool) curveSupportGetDx;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.ammwrapper.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly { stor_slot := slot }
                              }
                          }
                          library RFQStorage {
                              bytes32 private constant STORAGE_SLOT = 0x9174e76494cfb023ddc1eb0effb6c12e107165382bbd0ecfddbc38ea108bbe52;
                              struct Storage {
                                  mapping(bytes32 => bool) transactionSeen;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.rfq.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly { stor_slot := slot }
                              }
                          }// SPDX-License-Identifier: MIT
                          pragma solidity ^0.6.5;
                          import "./interfaces/IPermanentStorage.sol";
                          import "./utils/lib_storage/PSStorage.sol";
                          contract PermanentStorage is IPermanentStorage {
                              // Constants do not have storage slot.
                              bytes32 public constant curveTokenIndexStorageId = 0xf4c750cdce673f6c35898d215e519b86e3846b1f0532fb48b84fe9d80f6de2fc; // keccak256("curveTokenIndex")
                              bytes32 public constant transactionSeenStorageId = 0x695d523b8578c6379a2121164fd8de334b9c5b6b36dff5408bd4051a6b1704d0;  // keccak256("transactionSeen")
                              bytes32 public constant relayerValidStorageId = 0x2c97779b4deaf24e9d46e02ec2699240a957d92782b51165b93878b09dd66f61;  // keccak256("relayerValid")
                              // New supported Curve pools
                              address public constant CURVE_renBTC_POOL = 0x93054188d876f558f4a66B2EF1d97d16eDf0895B;
                              address public constant CURVE_sBTC_POOL = 0x7fC77b5c7614E1533320Ea6DDc2Eb61fa00A9714;
                              address public constant CURVE_hBTC_POOL = 0x4CA9b3063Ec5866A4B82E437059D2C43d1be596F;
                              address public constant CURVE_sETH_POOL = 0xc5424B857f758E906013F3555Dad202e4bdB4567;
                              // Curve coins
                              address private constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant renBTC = 0xEB4C2781e4ebA804CE9a9803C67d0893436bB27D;
                              address private constant wBTC = 0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599;
                              address private constant sBTC = 0xfE18be6b3Bd88A2D2A7f928d00292E7a9963CfC6;
                              address private constant hBTC = 0x0316EB71485b0Ab14103307bf65a021042c6d380;
                              address private constant sETH = 0x5e74C9036fb86BD7eCdcb084a0673EFc32eA31cb;
                              // Below are the variables which consume storage slots.
                              address public operator;
                              string public version;  // Current version of the contract
                              mapping(bytes32 => mapping(address => bool)) private permission;
                              // Operator events
                              event TransferOwnership(address newOperator);
                              event SetPermission(bytes32 storageId, address role, bool enabled);
                              event UpgradeAMMWrapper(address newAMMWrapper);
                              event UpgradePMM(address newPMM);
                              event UpgradeRFQ(address newRFQ);
                              event UpgradeWETH(address newWETH);
                              /************************************************************
                              *          Access control and ownership management          *
                              *************************************************************/
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "PermanentStorage: not the operator");
                                  _;
                              }
                              modifier validRole(bool _enabled, address _role) {
                                  if (_enabled) {
                                      require(
                                          (_role == operator) || (_role == ammWrapperAddr()) || (_role == pmmAddr() || (_role == rfqAddr())),
                                          "PermanentStorage: not a valid role"
                                      );
                                  }
                                  _;
                              }
                              modifier isPermitted(bytes32 _storageId, address _role) {
                                  require(permission[_storageId][_role], "PermanentStorage: has no permission");
                                  _;
                              }
                              function transferOwnership(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "PermanentStorage: operator can not be zero address");
                                  operator = _newOperator;
                                  emit TransferOwnership(_newOperator);
                              }
                              /// @dev Set permission for entity to write certain storage.
                              function setPermission(bytes32 _storageId, address _role, bool _enabled) external onlyOperator validRole(_enabled, _role) {
                                  permission[_storageId][_role] = _enabled;
                                  emit SetPermission(_storageId, _role, _enabled);
                              }
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              /// @dev Replacing constructor and initialize the contract. This function should only be called once.
                              function initialize() external {
                                  require(
                                      keccak256(abi.encodePacked(version)) == keccak256(abi.encodePacked("5.1.0")),
                                      "PermanentStorage: not upgrading from 5.1.0 version"
                                  );
                                  // upgrade from 5.1.0 to 5.2.0
                                  version = "5.2.0";
                                  // register renBTC pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_renBTC_POOL][renBTC] = 1; // renBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_renBTC_POOL][wBTC] = 2; // wBTC
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_renBTC_POOL] = false;
                                  // register sBTC pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sBTC_POOL][renBTC] = 1; // renBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sBTC_POOL][wBTC] = 2; // wBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sBTC_POOL][sBTC] = 3; // sBTC
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_sBTC_POOL] = false;
                                  // register hBTC pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_hBTC_POOL][hBTC] = 1; // hBTC
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_hBTC_POOL][wBTC] = 2; // wBTC
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_hBTC_POOL] = false;
                                  // register sETH pool
                                  // coins, exchange
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sETH_POOL][ETH] = 1; // ETH
                                  AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[CURVE_sETH_POOL][sETH] = 2; // sETH
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[CURVE_sETH_POOL] = false;
                              }
                              /************************************************************
                              *                     Getter functions                      *
                              *************************************************************/
                              function hasPermission(bytes32 _storageId, address _role) external view returns (bool) {
                                  return permission[_storageId][_role];
                              }
                              function ammWrapperAddr() public view returns (address) {
                                  return PSStorage.getStorage().ammWrapperAddr;
                              }
                              function pmmAddr() public view returns (address) {
                                  return PSStorage.getStorage().pmmAddr;
                              }
                              function rfqAddr() public view returns (address) {
                                  return PSStorage.getStorage().rfqAddr;
                              }
                              function wethAddr() override external view returns (address) {
                                  return PSStorage.getStorage().wethAddr;
                              }
                              function getCurvePoolInfo(address _makerAddr, address _takerAssetAddr, address _makerAssetAddr) override external view returns (int128 takerAssetIndex, int128 makerAssetIndex, uint16 swapMethod, bool supportGetDx) {
                                  // underlying_coins
                                  int128 i = AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][_takerAssetAddr];
                                  int128 j = AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][_makerAssetAddr];
                                  supportGetDx = AMMWrapperStorage.getStorage().curveSupportGetDx[_makerAddr];
                                  swapMethod = 0;
                                  if (i != 0 && j != 0) {
                                      // in underlying_coins list
                                      takerAssetIndex = i;
                                      makerAssetIndex = j;
                                      // exchange_underlying
                                      swapMethod = 2;
                                  } else {
                                      // in coins list
                                      int128 iWrapped = AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][_takerAssetAddr];
                                      int128 jWrapped = AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][_makerAssetAddr];
                                      if (iWrapped != 0 && jWrapped != 0) {
                                          takerAssetIndex = iWrapped;
                                          makerAssetIndex = jWrapped;
                                          // exchange
                                          swapMethod = 1;
                                      } else {
                                          revert("PermanentStorage: invalid pair");
                                      }
                                  }
                                  return (takerAssetIndex, makerAssetIndex, swapMethod, supportGetDx);
                              }
                              /* 
                              NOTE: `isTransactionSeen` is replaced by `isAMMTransactionSeen`. It is kept for backward compatability.
                              It should be removed from AMM 5.2.1 upward.
                              */
                              function isTransactionSeen(bytes32 _transactionHash) override external view returns (bool) {
                                  return AMMWrapperStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isAMMTransactionSeen(bytes32 _transactionHash) override external view returns (bool) {
                                  return AMMWrapperStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isRFQTransactionSeen(bytes32 _transactionHash) override external view returns (bool) {
                                  return RFQStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isRelayerValid(address _relayer) override external view returns (bool) {
                                  return AMMWrapperStorage.getStorage().relayerValid[_relayer];
                              }
                              /************************************************************
                              *           Management functions for Operator               *
                              *************************************************************/
                              /// @dev Update AMMWrapper contract address.
                              function upgradeAMMWrapper(address _newAMMWrapper) external onlyOperator {
                                  PSStorage.getStorage().ammWrapperAddr = _newAMMWrapper;
                                  emit UpgradeAMMWrapper(_newAMMWrapper);
                              }
                              /// @dev Update PMM contract address.
                              function upgradePMM(address _newPMM) external onlyOperator {
                                  PSStorage.getStorage().pmmAddr = _newPMM;
                                  emit UpgradePMM(_newPMM);
                              }
                              /// @dev Update RFQ contract address.
                              function upgradeRFQ(address _newRFQ) external onlyOperator {
                                  PSStorage.getStorage().rfqAddr = _newRFQ;
                                  emit UpgradeRFQ(_newRFQ);
                              }
                              /// @dev Update WETH contract address.
                              function upgradeWETH(address _newWETH) external onlyOperator {
                                  PSStorage.getStorage().wethAddr = _newWETH;
                                  emit UpgradeWETH(_newWETH);
                              }
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              function setCurvePoolInfo(address _makerAddr, address[] calldata _underlyingCoins, address[] calldata _coins, bool _supportGetDx) override external isPermitted(curveTokenIndexStorageId, msg.sender) {
                                  int128 underlyingCoinsLength = int128(_underlyingCoins.length);
                                  for (int128 i = 0 ; i < underlyingCoinsLength; i++) {
                                      address assetAddr = _underlyingCoins[uint256(i)];
                                      // underlying coins for original DAI, USDC, TUSD
                                      AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][assetAddr] = i + 1;  // Start the index from 1
                                  }
                                  int128 coinsLength = int128(_coins.length);
                                  for (int128 i = 0 ; i < coinsLength; i++) {
                                      address assetAddr = _coins[uint256(i)];
                                      // wrapped coins for cDAI, cUSDC, yDAI, yUSDC, yTUSD, yBUSD
                                      AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][assetAddr] = i + 1;  // Start the index from 1
                                  }
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[_makerAddr] = _supportGetDx;
                              }
                              /* 
                              NOTE: `setTransactionSeen` is replaced by `setAMMTransactionSeen`. It is kept for backward compatability.
                              It should be removed from AMM 5.2.1 upward.
                              */
                              function setTransactionSeen(bytes32 _transactionHash) override external isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!AMMWrapperStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  AMMWrapperStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setAMMTransactionSeen(bytes32 _transactionHash) override external isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!AMMWrapperStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  AMMWrapperStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setRFQTransactionSeen(bytes32 _transactionHash) override external isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!RFQStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  RFQStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setRelayersValid(address[] calldata _relayers, bool[] calldata _isValids) override external isPermitted(relayerValidStorageId, msg.sender) {
                                  require(_relayers.length == _isValids.length, "PermanentStorage: inputs length mismatch");
                                  for (uint256 i = 0; i < _relayers.length; i++) {
                                      AMMWrapperStorage.getStorage().relayerValid[_relayers[i]] = _isValids[i];
                                  }
                              }
                          }
                          pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "@openzeppelin/contracts/math/SafeMath.sol";
                          import "./AMMWrapper.sol";
                          import "./interfaces/ISpender.sol";
                          import "./interfaces/IUniswapRouterV2.sol";
                          import "./interfaces/IUniswapV3SwapRouter.sol";
                          import "./interfaces/IPermanentStorage.sol";
                          import "./utils/UniswapV3PathLib.sol";
                          contract AMMWrapperWithPath is AMMWrapper {
                              using SafeMath for uint256;
                              using SafeERC20 for IERC20;
                              using Path for bytes;
                              // Constants do not have storage slot.
                              address public constant UNISWAP_V3_ROUTER_ADDRESS = 0xE592427A0AEce92De3Edee1F18E0157C05861564;
                              event Swapped(
                                  TxMetaData,
                                  Order order
                              );
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              constructor (
                                  address _operator,
                                  uint256 _subsidyFactor,
                                  address _userProxy,
                                  ISpender _spender,
                                  IPermanentStorage _permStorage,
                                  IWETH _weth
                              ) public AMMWrapper(_operator, _subsidyFactor, _userProxy, _spender, _permStorage, _weth) {}
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              function trade(
                                  Order memory _order,
                                  uint256 _feeFactor,
                                  bytes calldata _sig,
                                  bytes calldata _makerSpecificData,
                                  address[] calldata _path
                              )
                                  payable
                                  external
                                  nonReentrant
                                  onlyUserProxy
                                  returns (uint256) 
                              {
                                  require(_order.deadline >= block.timestamp, "AMMWrapper: expired order");
                                  TxMetaData memory txMetaData;
                                  InternalTxData memory internalTxData;
                                  // These variables are copied straight from function parameters and
                                  // used to bypass stack too deep error.
                                  txMetaData.subsidyFactor = uint16(subsidyFactor);
                                  txMetaData.feeFactor = uint16(_feeFactor);
                                  internalTxData.makerSpecificData = _makerSpecificData;
                                  internalTxData.path = _path;
                                  if (! permStorage.isRelayerValid(tx.origin)) {
                                      txMetaData.feeFactor = (txMetaData.subsidyFactor > txMetaData.feeFactor) ? txMetaData.subsidyFactor : txMetaData.feeFactor;
                                      txMetaData.subsidyFactor = 0;
                                  }
                                  // Assign trade vairables
                                  internalTxData.fromEth = (_order.takerAssetAddr == ZERO_ADDRESS || _order.takerAssetAddr == ETH_ADDRESS);
                                  internalTxData.toEth = (_order.makerAssetAddr == ZERO_ADDRESS || _order.makerAssetAddr == ETH_ADDRESS);
                                  if(_isCurve(_order.makerAddr)) {
                                      // PermanetStorage can recognize `ETH_ADDRESS` but not `ZERO_ADDRESS`.
                                      // Convert it to `ETH_ADDRESS` as passed in `_order.takerAssetAddr` or `_order.makerAssetAddr` might be `ZERO_ADDRESS`.
                                      internalTxData.takerAssetInternalAddr = internalTxData.fromEth ? ETH_ADDRESS : _order.takerAssetAddr;
                                      internalTxData.makerAssetInternalAddr = internalTxData.toEth ? ETH_ADDRESS : _order.makerAssetAddr;
                                  } else {
                                      internalTxData.takerAssetInternalAddr = internalTxData.fromEth ? address(weth) : _order.takerAssetAddr;
                                      internalTxData.makerAssetInternalAddr = internalTxData.toEth ? address(weth) : _order.makerAssetAddr;
                                  }
                                  txMetaData.transactionHash = _verify(
                                      _order,
                                      _sig
                                  );
                                  _prepare(_order, internalTxData);
                                  (txMetaData.source, txMetaData.receivedAmount) = _swapWithPath(
                                      _order,
                                      txMetaData,
                                      internalTxData
                                  );
                                  // Settle
                                  txMetaData.settleAmount = _settle(
                                      _order,
                                      txMetaData,
                                      internalTxData
                                  );
                                  emit Swapped(
                                      txMetaData,
                                      _order
                                  );
                                  return txMetaData.settleAmount;
                              }
                              /**
                               * @dev internal function of `trade`.
                               * Used to tell if maker is Curve.
                               */
                              function _isCurve(address _makerAddr) override internal pure returns (bool) {
                                  if (
                                      _makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      _makerAddr == UNISWAP_V3_ROUTER_ADDRESS ||
                                      _makerAddr == SUSHISWAP_ROUTER_ADDRESS
                                  ) return false;
                                  else return true;
                              }
                              /**
                               * @dev internal function of `trade`.
                               * It executes the swap on chosen AMM.
                               */
                              function _swapWithPath(
                                  Order memory _order,
                                  TxMetaData memory _txMetaData,
                                  InternalTxData memory _internalTxData
                              )
                                  internal
                                  approveTakerAsset(_internalTxData.takerAssetInternalAddr, _order.makerAddr)
                                  returns (string memory source, uint256 receivedAmount)
                              {
                                  // Swap
                                  // minAmount = makerAssetAmount * (10000 - subsidyFactor) / 10000
                                  uint256 minAmount = _order.makerAssetAmount.mul((BPS_MAX.sub(_txMetaData.subsidyFactor))).div(BPS_MAX);
                                  if (_order.makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      _order.makerAddr == SUSHISWAP_ROUTER_ADDRESS) {
                                      source = (_order.makerAddr == SUSHISWAP_ROUTER_ADDRESS) ? "SushiSwap" : "Uniswap V2";
                                      // Sushiswap shares the same interface as Uniswap's
                                      receivedAmount = _tradeUniswapV2TokenToToken(
                                          _order.makerAddr,
                                          _internalTxData.takerAssetInternalAddr,
                                          _internalTxData.makerAssetInternalAddr,
                                          _order.takerAssetAmount,
                                          minAmount,
                                          _order.deadline,
                                          _internalTxData.path
                                      );
                                  } else if (_order.makerAddr == UNISWAP_V3_ROUTER_ADDRESS) {
                                      source = "Uniswap V3";
                                      receivedAmount = _tradeUniswapV3TokenToToken(
                                          _order.makerAddr,
                                          _internalTxData.takerAssetInternalAddr,
                                          _internalTxData.makerAssetInternalAddr,
                                          _order.deadline,
                                          _order.takerAssetAmount,
                                          minAmount,
                                          _internalTxData.makerSpecificData
                                      );
                                  } else {
                                      CurveData memory curveData;
                                      (
                                          curveData.fromTokenCurveIndex,
                                          curveData.toTokenCurveIndex,
                                          curveData.swapMethod,
                                      ) = permStorage.getCurvePoolInfo(
                                          _order.makerAddr,
                                          _internalTxData.takerAssetInternalAddr,
                                          _internalTxData.makerAssetInternalAddr
                                      );
                                      require(curveData.swapMethod != 0,"AMMWrapper: swap method not registered");
                                      if (curveData.fromTokenCurveIndex > 0 && curveData.toTokenCurveIndex > 0) {
                                          source = "Curve";
                                          // Substract index by 1 because indices stored in `permStorage` starts from 1
                                          curveData.fromTokenCurveIndex = curveData.fromTokenCurveIndex - 1;
                                          curveData.toTokenCurveIndex = curveData.toTokenCurveIndex - 1;
                                          // Curve does not return amount swapped so we need to record balance change instead.
                                          uint256 balanceBeforeTrade = _getSelfBalance(_internalTxData.makerAssetInternalAddr);
                                          _tradeCurveTokenToToken(
                                              _order.makerAddr,
                                              curveData.fromTokenCurveIndex,
                                              curveData.toTokenCurveIndex,
                                              _order.takerAssetAmount,
                                              minAmount,
                                              curveData.swapMethod
                                          );
                                          uint256 balanceAfterTrade = _getSelfBalance(_internalTxData.makerAssetInternalAddr);
                                          receivedAmount = balanceAfterTrade.sub(balanceBeforeTrade);
                                      } else {
                                          revert("AMMWrapper: unsupported makerAddr");
                                      }
                                  }
                              }
                              function _tradeUniswapV2TokenToToken(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _takerAssetAmount,
                                  uint256 _makerAssetAmount,
                                  uint256 _deadline,
                                  address[] memory _path
                              )
                                  internal 
                                  returns (uint256) 
                              {
                                  IUniswapRouterV2 router = IUniswapRouterV2(_makerAddr);
                                  if (_path.length == 0) {
                                      _path = new address[](2);
                                      _path[0] = _takerAssetAddr;
                                      _path[1] = _makerAssetAddr;
                                  } else {
                                      require(_path.length >= 2, "AMMWrapper: path length must be at least two");
                                      require(_path[0] == _takerAssetAddr, "AMMWrapper: first element of path must match taker asset");
                                      require(_path[_path.length - 1] == _makerAssetAddr, "AMMWrapper: last element of path must match maker asset");
                                  }
                                  uint256[] memory amounts = router.swapExactTokensForTokens(
                                      _takerAssetAmount,
                                      _makerAssetAmount,
                                      _path,
                                      address(this),
                                      _deadline
                                  );
                                  return amounts[amounts.length - 1];
                              }
                              function _validateUniswapV3Path(
                                  bytes memory _path,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr
                              ) internal {
                                  (address tokenA, address tokenB, ) = _path.decodeFirstPool();
                                  if (_path.hasMultiplePools()) {
                                      _path = _path.skipToken();
                                      while (_path.hasMultiplePools()) {
                                          _path = _path.skipToken();
                                      }
                                      (, tokenB, ) = _path.decodeFirstPool();
                                  }
                                  require(tokenA == _takerAssetAddr, "AMMWrapper: first element of path must match taker asset");
                                  require(tokenB == _makerAssetAddr, "AMMWrapper: last element of path must match maker asset");
                              }
                              function _tradeUniswapV3TokenToToken(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _deadline,
                                  uint256 _takerAssetAmount,
                                  uint256 _makerAssetAmount,
                                  bytes memory _makerSpecificData
                              )
                                  internal 
                                  returns (uint256 amountOut) 
                              {
                                  ISwapRouter router = ISwapRouter(_makerAddr);
                                  // swapType:
                                  // 1: exactInputSingle, 2: exactInput
                                  uint8 swapType = uint8(uint256(_makerSpecificData.readBytes32(0)));
                                  if (swapType == 1) {
                                      (, uint24 poolFee) = abi.decode(_makerSpecificData, (uint8, uint24));
                                      ISwapRouter.ExactInputSingleParams memory exactInputSingleParams;
                                      exactInputSingleParams.tokenIn = _takerAssetAddr;
                                      exactInputSingleParams.tokenOut = _makerAssetAddr;
                                      exactInputSingleParams.fee = poolFee;
                                      exactInputSingleParams.recipient = address(this);
                                      exactInputSingleParams.deadline = _deadline;
                                      exactInputSingleParams.amountIn = _takerAssetAmount;
                                      exactInputSingleParams.amountOutMinimum = _makerAssetAmount;
                                      exactInputSingleParams.sqrtPriceLimitX96 = 0;
                                      amountOut = router.exactInputSingle(exactInputSingleParams);
                                  } else if (swapType == 2) {
                                      (, bytes memory path) = abi.decode(_makerSpecificData, (uint8, bytes));
                                      _validateUniswapV3Path(path, _takerAssetAddr, _makerAssetAddr);
                                      ISwapRouter.ExactInputParams memory exactInputParams;
                                      exactInputParams.path = path;
                                      exactInputParams.recipient = address(this);
                                      exactInputParams.deadline = _deadline;
                                      exactInputParams.amountIn = _takerAssetAmount;
                                      exactInputParams.amountOutMinimum = _makerAssetAmount;
                                      amountOut = router.exactInput(exactInputParams);
                                  } else {
                                      revert("AMMWrapper: unsupported UniswapV3 swap type");
                                  }
                              }
                          }
                          pragma solidity ^0.6.0;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
                          import "@openzeppelin/contracts/math/SafeMath.sol";
                          import "./interfaces/ISpender.sol";
                          import "./interfaces/IUniswapExchange.sol";
                          import "./interfaces/IUniswapFactory.sol";
                          import "./interfaces/IUniswapRouterV2.sol";
                          import "./interfaces/ICurveFi.sol";
                          import "./interfaces/IAMM.sol";
                          import "./interfaces/IWeth.sol";
                          import "./interfaces/IPermanentStorage.sol";
                          import "./utils/AMMLibEIP712.sol";
                          import "./utils/SignatureValidator.sol";
                          contract AMMWrapper is
                              IAMM,
                              ReentrancyGuard,
                              AMMLibEIP712,
                              SignatureValidator
                          {
                              using SafeMath for uint256;
                              using SafeERC20 for IERC20;
                              // Constants do not have storage slot.
                              string public constant version = "5.2.0";
                              uint256 internal constant MAX_UINT = 2**256 - 1;
                              uint256 internal constant BPS_MAX = 10000;
                              address internal constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address internal constant ZERO_ADDRESS = address(0);
                              address public immutable userProxy;
                              IWETH public immutable weth;
                              IPermanentStorage public immutable permStorage;
                              address public constant UNISWAP_V2_ROUTER_02_ADDRESS = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
                              address public constant SUSHISWAP_ROUTER_ADDRESS = 0xd9e1cE17f2641f24aE83637ab66a2cca9C378B9F;
                              // Below are the variables which consume storage slots.
                              address public operator;
                              uint256 public subsidyFactor;
                              ISpender public spender;
                              /* Struct and event declaration */
                              // Group the local variables together to prevent
                              // Compiler error: Stack too deep, try removing local variables.
                              struct TxMetaData {
                                  string source;
                                  bytes32 transactionHash;
                                  uint256 settleAmount;
                                  uint256 receivedAmount;
                                  uint16 feeFactor;
                                  uint16 subsidyFactor;
                              }
                              struct InternalTxData {
                                  bool fromEth;
                                  bool toEth;
                                  address takerAssetInternalAddr;
                                  address makerAssetInternalAddr;
                                  address[] path;
                                  bytes makerSpecificData;
                              }
                              struct CurveData {
                                  int128 fromTokenCurveIndex;
                                  int128 toTokenCurveIndex;
                                  uint16 swapMethod;
                              }
                              // Operator events
                              event TransferOwnership(address newOperator);
                              event UpgradeSpender(address newSpender);
                              event SetSubsidyFactor(uint256 newSubisdyFactor);
                              event AllowTransfer(address spender);
                              event DisallowTransfer(address spender);
                              event DepositETH(uint256 ethBalance);
                              event Swapped(
                                  string source,
                                  bytes32 indexed transactionHash,
                                  address indexed userAddr,
                                  address takerAssetAddr,
                                  uint256 takerAssetAmount,
                                  address makerAddr,
                                  address makerAssetAddr,
                                  uint256 makerAssetAmount,
                                  address receiverAddr,
                                  uint256 settleAmount,
                                  uint256 receivedAmount,
                                  uint16 feeFactor,
                                  uint16 subsidyFactor
                              );
                              receive() external payable {}
                              /************************************************************
                              *          Access control and ownership management          *
                              *************************************************************/
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "AMMWrapper: not the operator");
                                  _;
                              }
                              modifier onlyUserProxy() {
                                  require(address(userProxy) == msg.sender, "AMMWrapper: not the UserProxy contract");
                                  _;
                              }
                              function transferOwnership(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "AMMWrapper: operator can not be zero address");
                                  operator = _newOperator;
                                  emit TransferOwnership(_newOperator);
                              }
                              /************************************************************
                              *                 Internal function modifier                *
                              *************************************************************/
                              modifier approveTakerAsset(address _takerAssetInternalAddr, address _makerAddr) {
                                  bool isTakerAssetETH = _isInternalAssetETH(_takerAssetInternalAddr);
                                  if (! isTakerAssetETH) IERC20(_takerAssetInternalAddr).safeApprove(_makerAddr, MAX_UINT);
                                  _;
                                  if (! isTakerAssetETH) IERC20(_takerAssetInternalAddr).safeApprove(_makerAddr, 0);
                              }
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              constructor (
                                  address _operator,
                                  uint256 _subsidyFactor,
                                  address _userProxy,
                                  ISpender _spender,
                                  IPermanentStorage _permStorage,
                                  IWETH _weth
                              ) public {
                                  operator = _operator;
                                  subsidyFactor = _subsidyFactor;
                                  userProxy = _userProxy;
                                  spender = _spender;
                                  permStorage = _permStorage;
                                  weth = _weth;
                              }
                              /************************************************************
                              *           Management functions for Operator               *
                              *************************************************************/
                              /**
                               * @dev set new Spender
                               */
                              function upgradeSpender(address _newSpender) external onlyOperator {
                                  require(_newSpender != address(0), "AMMWrapper: spender can not be zero address");
                                  spender = ISpender(_newSpender);
                                  emit UpgradeSpender(_newSpender);
                              }
                              function setSubsidyFactor(uint256 _subsidyFactor) external onlyOperator {
                                  subsidyFactor = _subsidyFactor;
                                  emit SetSubsidyFactor(_subsidyFactor);
                              }
                              /**
                               * @dev approve spender to transfer tokens from this contract. This is used to collect fee.
                               */
                              function setAllowance(address[] calldata _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, MAX_UINT);
                                      emit AllowTransfer(_spender);
                                  }
                              }
                              function closeAllowance(address[] calldata _tokenList, address _spender) override external onlyOperator {
                                  for (uint256 i = 0 ; i < _tokenList.length; i++) {
                                      IERC20(_tokenList[i]).safeApprove(_spender, 0);
                                      emit DisallowTransfer(_spender);
                                  }
                              }
                              /**
                               * @dev convert collected ETH to WETH
                               */
                              function depositETH() external onlyOperator {
                                  uint256 balance = address(this).balance;
                                  if (balance > 0) {
                                      weth.deposit{value: balance}();
                                      emit DepositETH(balance);
                                  }
                              }
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              function trade(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _takerAssetAmount,
                                  uint256 _makerAssetAmount,
                                  uint256 _feeFactor,
                                  address _userAddr,
                                  address payable _receiverAddr,
                                  uint256 _salt,
                                  uint256 _deadline,
                                  bytes calldata _sig
                              )
                                  override
                                  payable
                                  external
                                  nonReentrant
                                  onlyUserProxy
                                  returns (uint256) 
                              {
                                  Order memory order = Order(
                                      _makerAddr,
                                      _takerAssetAddr,
                                      _makerAssetAddr,
                                      _takerAssetAmount,
                                      _makerAssetAmount,
                                      _userAddr,
                                      _receiverAddr,
                                      _salt,
                                      _deadline
                                  );
                                  require(order.deadline >= block.timestamp, "AMMWrapper: expired order");
                                  TxMetaData memory txMetaData;
                                  InternalTxData memory internalTxData;
                                  // These variables are copied straight from function parameters and
                                  // used to bypass stack too deep error.
                                  txMetaData.subsidyFactor = uint16(subsidyFactor);
                                  txMetaData.feeFactor = uint16(_feeFactor);
                                  if (! permStorage.isRelayerValid(tx.origin)) {
                                      txMetaData.feeFactor = (txMetaData.subsidyFactor > txMetaData.feeFactor) ? txMetaData.subsidyFactor : txMetaData.feeFactor;
                                      txMetaData.subsidyFactor = 0;
                                  }
                                  // Assign trade vairables
                                  internalTxData.fromEth = (order.takerAssetAddr == ZERO_ADDRESS || order.takerAssetAddr == ETH_ADDRESS);
                                  internalTxData.toEth = (order.makerAssetAddr == ZERO_ADDRESS || order.makerAssetAddr == ETH_ADDRESS);
                                  if(_isCurve(order.makerAddr)) {
                                      // PermanetStorage can recognize `ETH_ADDRESS` but not `ZERO_ADDRESS`.
                                      // Convert it to `ETH_ADDRESS` as passed in `order.takerAssetAddr` or `order.makerAssetAddr` might be `ZERO_ADDRESS`.
                                      internalTxData.takerAssetInternalAddr = internalTxData.fromEth ? ETH_ADDRESS : order.takerAssetAddr;
                                      internalTxData.makerAssetInternalAddr = internalTxData.toEth ? ETH_ADDRESS : order.makerAssetAddr;
                                  } else {
                                      internalTxData.takerAssetInternalAddr = internalTxData.fromEth ? address(weth) : order.takerAssetAddr;
                                      internalTxData.makerAssetInternalAddr = internalTxData.toEth ? address(weth) : order.makerAssetAddr;
                                  }
                                  txMetaData.transactionHash = _verify(
                                      order,
                                      _sig
                                  );
                                  _prepare(order, internalTxData);
                                  (txMetaData.source, txMetaData.receivedAmount) = _swap(
                                      order,
                                      txMetaData,
                                      internalTxData
                                  );
                                  // Settle
                                  txMetaData.settleAmount = _settle(
                                      order,
                                      txMetaData,
                                      internalTxData
                                  );
                                  emit Swapped(
                                      txMetaData.source,
                                      txMetaData.transactionHash,
                                      order.userAddr,
                                      order.takerAssetAddr,
                                      order.takerAssetAmount,
                                      order.makerAddr,
                                      order.makerAssetAddr,
                                      order.makerAssetAmount,
                                      order.receiverAddr,
                                      txMetaData.settleAmount,
                                      txMetaData.receivedAmount,
                                      txMetaData.feeFactor,
                                      txMetaData.subsidyFactor
                                  );
                                  return txMetaData.settleAmount;
                              }
                              /**
                               * @dev internal function of `trade`.
                               * Used to tell if maker is Curve.
                               */
                              function _isCurve(address _makerAddr) virtual internal pure returns (bool) {
                                  if (
                                      _makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      _makerAddr == SUSHISWAP_ROUTER_ADDRESS
                                  ) return false;
                                  else return true;
                              }
                              /**
                               * @dev internal function of `trade`.
                               * Used to tell if internal asset is ETH.
                               */
                              function _isInternalAssetETH(address _internalAssetAddr) internal pure returns (bool) {
                                  if (_internalAssetAddr == ETH_ADDRESS || _internalAssetAddr == ZERO_ADDRESS) return true;
                                  else return false;
                              }
                              /**
                               * @dev internal function of `trade`.
                               * Get this contract's eth balance or token balance.
                               */
                              function _getSelfBalance(address _makerAssetInternalAddr) internal view returns (uint256) {
                                  if (_isInternalAssetETH(_makerAssetInternalAddr)) {
                                      return address(this).balance;
                                  } else {
                                      return IERC20(_makerAssetInternalAddr).balanceOf(address(this));
                                  }
                              }
                              /**
                               * @dev internal function of `trade`.
                               * It verifies user signature and store tx hash to prevent replay attack.
                               */
                              function _verify(
                                  Order memory _order,
                                  bytes calldata _sig
                              ) internal returns (bytes32 transactionHash) {
                                  // Verify user signature
                                  // TRADE_WITH_PERMIT_TYPEHASH = keccak256("tradeWithPermit(address makerAddr,address takerAssetAddr,address makerAssetAddr,uint256 takerAssetAmount,uint256 makerAssetAmount,address userAddr,address receiverAddr,uint256 salt,uint256 deadline)");
                                  transactionHash = keccak256(
                                      abi.encode(
                                          TRADE_WITH_PERMIT_TYPEHASH,
                                          _order.makerAddr,
                                          _order.takerAssetAddr,
                                          _order.makerAssetAddr,
                                          _order.takerAssetAmount,
                                          _order.makerAssetAmount,
                                          _order.userAddr,
                                          _order.receiverAddr,
                                          _order.salt,
                                          _order.deadline
                                      )
                                  );
                                  bytes32 EIP712SignDigest = keccak256(
                                      abi.encodePacked(
                                          EIP191_HEADER,
                                          EIP712_DOMAIN_SEPARATOR,
                                          transactionHash
                                      )
                                  );
                                  require(isValidSignature(_order.userAddr, EIP712SignDigest, bytes(""), _sig), "AMMWrapper: invalid user signature");
                                  // Set transaction as seen, PermanentStorage would throw error if transaction already seen.
                                  permStorage.setAMMTransactionSeen(transactionHash);
                              }
                              /**
                               * @dev internal function of `trade`.
                               * It executes the swap on chosen AMM.
                               */
                              function _prepare(Order memory _order, InternalTxData memory _internalTxData) internal {
                                  // Transfer asset from user and deposit to weth if needed
                                  if (_internalTxData.fromEth) {
                                      require(msg.value > 0, "AMMWrapper: msg.value is zero");
                                      require(_order.takerAssetAmount == msg.value, "AMMWrapper: msg.value doesn't match");
                                      // Deposit ETH to WETH if internal asset is WETH instead of ETH
                                      if (! _isInternalAssetETH(_internalTxData.takerAssetInternalAddr)) {
                                          weth.deposit{value: msg.value}();
                                      }
                                  } else {
                                      // other ERC20 tokens
                                      spender.spendFromUser(_order.userAddr, _order.takerAssetAddr, _order.takerAssetAmount);
                                  }
                              }
                              /**
                               * @dev internal function of `trade`.
                               * It executes the swap on chosen AMM.
                               */
                              function _swap(
                                  Order memory _order,
                                  TxMetaData memory _txMetaData,
                                  InternalTxData memory _internalTxData
                              )
                                  internal
                                  approveTakerAsset(_internalTxData.takerAssetInternalAddr, _order.makerAddr)
                                  returns (string memory source, uint256 receivedAmount)
                              {
                                  // Swap
                                  // minAmount = makerAssetAmount * (10000 - subsidyFactor) / 10000
                                  uint256 minAmount = _order.makerAssetAmount.mul((BPS_MAX.sub(_txMetaData.subsidyFactor))).div(BPS_MAX);
                                  if (_order.makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      _order.makerAddr == SUSHISWAP_ROUTER_ADDRESS) {
                                      source = (_order.makerAddr == SUSHISWAP_ROUTER_ADDRESS) ? "SushiSwap" : "Uniswap V2";
                                      // Sushiswap shares the same interface as Uniswap's
                                      receivedAmount = _tradeUniswapV2TokenToToken(
                                          _order.makerAddr,
                                          _internalTxData.takerAssetInternalAddr,
                                          _internalTxData.makerAssetInternalAddr,
                                          _order.takerAssetAmount,
                                          minAmount,
                                          _order.deadline
                                      );
                                  } else {
                                      CurveData memory curveData;
                                      (
                                          curveData.fromTokenCurveIndex,
                                          curveData.toTokenCurveIndex,
                                          curveData.swapMethod,
                                      ) = permStorage.getCurvePoolInfo(
                                          _order.makerAddr,
                                          _internalTxData.takerAssetInternalAddr,
                                          _internalTxData.makerAssetInternalAddr
                                      );
                                      require(curveData.swapMethod != 0, "AMMWrapper: swap method not registered");
                                      if (curveData.fromTokenCurveIndex > 0 && curveData.toTokenCurveIndex > 0) {
                                          source = "Curve";
                                          // Substract index by 1 because indices stored in `permStorage` starts from 1
                                          curveData.fromTokenCurveIndex = curveData.fromTokenCurveIndex - 1;
                                          curveData.toTokenCurveIndex = curveData.toTokenCurveIndex - 1;
                                          // Curve does not return amount swapped so we need to record balance change instead.
                                          uint256 balanceBeforeTrade = _getSelfBalance(_internalTxData.makerAssetInternalAddr);
                                          _tradeCurveTokenToToken(
                                              _order.makerAddr,
                                              curveData.fromTokenCurveIndex,
                                              curveData.toTokenCurveIndex,
                                              _order.takerAssetAmount,
                                              minAmount,
                                              curveData.swapMethod
                                          );
                                          uint256 balanceAfterTrade = _getSelfBalance(_internalTxData.makerAssetInternalAddr);
                                          receivedAmount = balanceAfterTrade.sub(balanceBeforeTrade);
                                      } else {
                                          revert("AMMWrapper: unsupported makerAddr");
                                      }
                                  }
                              }
                              /**
                               * @dev internal function of `trade`.
                               * It collects fee from the trade or compensates the trade based on the actual amount swapped.
                               */
                              function _settle(
                                  Order memory _order,
                                  TxMetaData memory _txMetaData,
                                  InternalTxData memory _internalTxData
                              )
                                  internal
                                  returns (uint256 settleAmount)
                              {
                                  // Convert var type from uint16 to uint256
                                  uint256 _feeFactor = _txMetaData.feeFactor;
                                  uint256 _subsidyFactor = _txMetaData.subsidyFactor;
                                  if (_txMetaData.receivedAmount == _order.makerAssetAmount) {
                                      settleAmount = _txMetaData.receivedAmount;
                                  } else if (_txMetaData.receivedAmount > _order.makerAssetAmount) {
                                      // shouldCollectFee = ((receivedAmount - makerAssetAmount) / receivedAmount) > (feeFactor / 10000)
                                      bool shouldCollectFee = _txMetaData.receivedAmount.sub(_order.makerAssetAmount).mul(BPS_MAX) > _feeFactor.mul(_txMetaData.receivedAmount);
                                      if (shouldCollectFee) {
                                          // settleAmount = receivedAmount * (1 - feeFactor) / 10000
                                          settleAmount = _txMetaData.receivedAmount.mul(BPS_MAX.sub(_feeFactor)).div(BPS_MAX);
                                      } else {
                                          settleAmount = _order.makerAssetAmount;
                                      }
                                  } else {
                                      require(_subsidyFactor > 0, "AMMWrapper: this trade will not be subsidized");
                                      // If fee factor is smaller than subsidy factor, choose fee factor as actual subsidy factor
                                      // since we should subsidize less if we charge less.
                                      uint256 actualSubsidyFactor = (_subsidyFactor < _feeFactor) ? _subsidyFactor : _feeFactor;
                                      // inSubsidyRange = ((makerAssetAmount - receivedAmount) / receivedAmount) > (actualSubsidyFactor / 10000)
                                      bool inSubsidyRange = _order.makerAssetAmount.sub(_txMetaData.receivedAmount).mul(BPS_MAX) <= actualSubsidyFactor.mul(_txMetaData.receivedAmount);
                                      require(inSubsidyRange, "AMMWrapper: amount difference larger than subsidy amount");
                                      uint256 selfBalance = _getSelfBalance(_internalTxData.makerAssetInternalAddr);
                                      bool hasEnoughToSubsidize = selfBalance >= _order.makerAssetAmount;
                                      if (! hasEnoughToSubsidize && _isInternalAssetETH(_internalTxData.makerAssetInternalAddr)) {
                                          // We treat ETH and WETH the same so we have to convert WETH to ETH if ETH balance is not enough.
                                          uint256 amountShort = _order.makerAssetAmount.sub(selfBalance);
                                          if (amountShort <= weth.balanceOf(address(this))) {
                                              // Withdraw the amount short from WETH
                                              weth.withdraw(amountShort);
                                              // Now we have enough
                                              hasEnoughToSubsidize = true;
                                          }
                                      }
                                      require(hasEnoughToSubsidize, "AMMWrapper: not enough savings to subsidize");
                                      settleAmount = _order.makerAssetAmount;
                                  }
                                  // Transfer token/ETH to receiver
                                  if (_internalTxData.toEth) {
                                      // Withdraw from WETH if internal maker asset is WETH
                                      if (! _isInternalAssetETH(_internalTxData.makerAssetInternalAddr)) {
                                          weth.withdraw(settleAmount);
                                      }
                                      _order.receiverAddr.transfer(settleAmount);
                                  } else {
                                      // other ERC20 tokens
                                      IERC20(_order.makerAssetAddr).safeTransfer(_order.receiverAddr, settleAmount);
                                  }
                              }
                              function _tradeCurveTokenToToken(
                                  address _makerAddr,
                                  int128 i,
                                  int128 j,
                                  uint256 _takerAssetAmount,
                                  uint256 _makerAssetAmount,
                                  uint16 swapMethod
                              ) 
                                  internal
                              {
                                  ICurveFi curve = ICurveFi(_makerAddr);
                                  if (swapMethod == 1) {
                                      curve.exchange{value: msg.value}(i, j, _takerAssetAmount, _makerAssetAmount);
                                  } else if (swapMethod == 2) {
                                      curve.exchange_underlying{value: msg.value}(i, j, _takerAssetAmount, _makerAssetAmount);
                                  }
                              }
                              function _tradeUniswapV2TokenToToken(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _takerAssetAmount,
                                  uint256 _makerAssetAmount,
                                  uint256 _deadline
                              )
                                  internal 
                                  returns (uint256) 
                              {
                                  IUniswapRouterV2 router = IUniswapRouterV2(_makerAddr);
                                  address[] memory path = new address[](2);
                                  path[0] = _takerAssetAddr;
                                  path[1] = _makerAssetAddr;
                                  uint256[] memory amounts = router.swapExactTokensForTokens(
                                      _takerAssetAmount,
                                      _makerAssetAmount,
                                      path,
                                      address(this),
                                      _deadline
                                  );
                                  return amounts[1];
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.5.0 <0.8.0;
                          interface IUniswapRouterV2 {
                              function swapExactTokensForTokens(
                                  uint256 amountIn,
                                  uint256 amountOutMin,
                                  address[] calldata path,
                                  address to,
                                  uint256 deadline
                              ) external returns (uint256[] memory amounts);
                              function addLiquidity(
                                  address tokenA,
                                  address tokenB,
                                  uint256 amountADesired,
                                  uint256 amountBDesired,
                                  uint256 amountAMin,
                                  uint256 amountBMin,
                                  address to,
                                  uint256 deadline
                              )
                                  external
                                  returns (
                                      uint256 amountA,
                                      uint256 amountB,
                                      uint256 liquidity
                                  );
                              function addLiquidityETH(
                                  address token,
                                  uint256 amountTokenDesired,
                                  uint256 amountTokenMin,
                                  uint256 amountETHMin,
                                  address to,
                                  uint256 deadline
                              )
                                  external
                                  payable
                                  returns (
                                      uint256 amountToken,
                                      uint256 amountETH,
                                      uint256 liquidity
                                  );
                              function removeLiquidity(
                                  address tokenA,
                                  address tokenB,
                                  uint256 liquidity,
                                  uint256 amountAMin,
                                  uint256 amountBMin,
                                  address to,
                                  uint256 deadline
                              ) external returns (uint256 amountA, uint256 amountB);
                              function getAmountsOut(uint256 amountIn, address[] calldata path)
                                  external
                                  view
                                  returns (uint256[] memory amounts);
                              function getAmountsIn(uint256 amountOut, address[] calldata path)
                                  external
                                  view
                                  returns (uint256[] memory amounts);
                              function swapETHForExactTokens(
                                  uint256 amountOut,
                                  address[] calldata path,
                                  address to,
                                  uint256 deadline
                              ) external payable returns (uint256[] memory amounts);
                              function swapExactETHForTokens(
                                  uint256 amountOutMin,
                                  address[] calldata path,
                                  address to,
                                  uint256 deadline
                              ) external payable returns (uint256[] memory amounts);
                          }// SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0 <0.8.0;
                          pragma experimental ABIEncoderV2;
                          import "./IUniswapV3SwapCallback.sol";
                          /// @title Router token swapping functionality
                          /// @notice Functions for swapping tokens via Uniswap V3
                          interface ISwapRouter is IUniswapV3SwapCallback {
                              struct ExactInputSingleParams {
                                  address tokenIn;
                                  address tokenOut;
                                  uint24 fee;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountIn;
                                  uint256 amountOutMinimum;
                                  uint160 sqrtPriceLimitX96;
                              }
                              /// @notice Swaps `amountIn` of one token for as much as possible of another token
                              /// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
                              /// @return amountOut The amount of the received token
                              function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);
                              struct ExactInputParams {
                                  bytes path;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountIn;
                                  uint256 amountOutMinimum;
                              }
                              /// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
                              /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
                              /// @return amountOut The amount of the received token
                              function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);
                              struct ExactOutputSingleParams {
                                  address tokenIn;
                                  address tokenOut;
                                  uint24 fee;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountOut;
                                  uint256 amountInMaximum;
                                  uint160 sqrtPriceLimitX96;
                              }
                              /// @notice Swaps as little as possible of one token for `amountOut` of another token
                              /// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
                              /// @return amountIn The amount of the input token
                              function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);
                              struct ExactOutputParams {
                                  bytes path;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountOut;
                                  uint256 amountInMaximum;
                              }
                              /// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
                              /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
                              /// @return amountIn The amount of the input token
                              function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
                          }// SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.6.0;
                          library BytesLib {
                              function slice(
                                  bytes memory _bytes,
                                  uint256 _start,
                                  uint256 _length
                              ) internal pure returns (bytes memory) {
                                  require(_length + 31 >= _length, "slice_overflow");
                                  require(_start + _length >= _start, "slice_overflow");
                                  require(_bytes.length >= _start + _length, "slice_outOfBounds");
                                  bytes memory tempBytes;
                                  assembly {
                                      switch iszero(_length)
                                          case 0 {
                                              // Get a location of some free memory and store it in tempBytes as
                                              // Solidity does for memory variables.
                                              tempBytes := mload(0x40)
                                              // The first word of the slice result is potentially a partial
                                              // word read from the original array. To read it, we calculate
                                              // the length of that partial word and start copying that many
                                              // bytes into the array. The first word we copy will start with
                                              // data we don't care about, but the last `lengthmod` bytes will
                                              // land at the beginning of the contents of the new array. When
                                              // we're done copying, we overwrite the full first word with
                                              // the actual length of the slice.
                                              let lengthmod := and(_length, 31)
                                              // The multiplication in the next line is necessary
                                              // because when slicing multiples of 32 bytes (lengthmod == 0)
                                              // the following copy loop was copying the origin's length
                                              // and then ending prematurely not copying everything it should.
                                              let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                                              let end := add(mc, _length)
                                              for {
                                                  // The multiplication in the next line has the same exact purpose
                                                  // as the one above.
                                                  let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                                              } lt(mc, end) {
                                                  mc := add(mc, 0x20)
                                                  cc := add(cc, 0x20)
                                              } {
                                                  mstore(mc, mload(cc))
                                              }
                                              mstore(tempBytes, _length)
                                              //update free-memory pointer
                                              //allocating the array padded to 32 bytes like the compiler does now
                                              mstore(0x40, and(add(mc, 31), not(31)))
                                          }
                                          //if we want a zero-length slice let's just return a zero-length array
                                          default {
                                              tempBytes := mload(0x40)
                                              //zero out the 32 bytes slice we are about to return
                                              //we need to do it because Solidity does not garbage collect
                                              mstore(tempBytes, 0)
                                              mstore(0x40, add(tempBytes, 0x20))
                                          }
                                  }
                                  return tempBytes;
                              }
                              function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                                  require(_start + 20 >= _start, "toAddress_overflow");
                                  require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
                                  address tempAddress;
                                  assembly {
                                      tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                                  }
                                  return tempAddress;
                              }
                              function toUint24(bytes memory _bytes, uint256 _start) internal pure returns (uint24) {
                                  require(_start + 3 >= _start, "toUint24_overflow");
                                  require(_bytes.length >= _start + 3, "toUint24_outOfBounds");
                                  uint24 tempUint;
                                  assembly {
                                      tempUint := mload(add(add(_bytes, 0x3), _start))
                                  }
                                  return tempUint;
                              }
                          }
                          /// @title Functions for manipulating path data for multihop swaps
                          library Path {
                              using BytesLib for bytes;
                              /// @dev The length of the bytes encoded address
                              uint256 private constant ADDR_SIZE = 20;
                              /// @dev The length of the bytes encoded fee
                              uint256 private constant FEE_SIZE = 3;
                              /// @dev The offset of a single token address and pool fee
                              uint256 private constant NEXT_OFFSET = ADDR_SIZE + FEE_SIZE;
                              /// @dev The offset of an encoded pool key
                              uint256 private constant POP_OFFSET = NEXT_OFFSET + ADDR_SIZE;
                              /// @dev The minimum length of an encoding that contains 2 or more pools
                              uint256 private constant MULTIPLE_POOLS_MIN_LENGTH = POP_OFFSET + NEXT_OFFSET;
                              /// @notice Returns true iff the path contains two or more pools
                              /// @param path The encoded swap path
                              /// @return True if path contains two or more pools, otherwise false
                              function hasMultiplePools(bytes memory path) internal pure returns (bool) {
                                  return path.length >= MULTIPLE_POOLS_MIN_LENGTH;
                              }
                              /// @notice Decodes the first pool in path
                              /// @param path The bytes encoded swap path
                              /// @return tokenA The first token of the given pool
                              /// @return tokenB The second token of the given pool
                              /// @return fee The fee level of the pool
                              function decodeFirstPool(bytes memory path)
                                  internal
                                  pure
                                  returns (
                                      address tokenA,
                                      address tokenB,
                                      uint24 fee
                                  )
                              {
                                  tokenA = path.toAddress(0);
                                  fee = path.toUint24(ADDR_SIZE);
                                  tokenB = path.toAddress(NEXT_OFFSET);
                              }
                              /// @notice Skips a token + fee element from the buffer and returns the remainder
                              /// @param path The swap path
                              /// @return The remaining token + fee elements in the path
                              function skipToken(bytes memory path) internal pure returns (bytes memory) {
                                  return path.slice(NEXT_OFFSET, path.length - NEXT_OFFSET);
                              }
                          }pragma solidity >=0.5.0 <0.8.0;
                          interface IUniswapExchange {
                              // Address of ERC20 token sold on this exchange
                              function tokenAddress() external view returns (address token);
                              // Address of Uniswap Factory
                              function factoryAddress() external view returns (address factory);
                              // Provide Liquidity
                              function addLiquidity(uint256 min_liquidity, uint256 max_tokens, uint256 deadline) external payable returns (uint256);
                              function removeLiquidity(uint256 amount, uint256 min_eth, uint256 min_tokens, uint256 deadline) external returns (uint256, uint256);
                              // Get Prices
                              function getEthToTokenInputPrice(uint256 eth_sold) external view returns (uint256 tokens_bought);
                              function getEthToTokenOutputPrice(uint256 tokens_bought) external view returns (uint256 eth_sold);
                              function getTokenToEthInputPrice(uint256 tokens_sold) external view returns (uint256 eth_bought);
                              function getTokenToEthOutputPrice(uint256 eth_bought) external view returns (uint256 tokens_sold);
                              // Trade ETH to ERC20
                              function ethToTokenSwapInput(uint256 min_tokens, uint256 deadline) external payable returns (uint256 tokens_bought);
                              function ethToTokenTransferInput(uint256 min_tokens, uint256 deadline, address recipient) external payable returns (uint256  tokens_bought);
                              function ethToTokenSwapOutput(uint256 tokens_bought, uint256 deadline) external payable returns (uint256  eth_sold);
                              function ethToTokenTransferOutput(uint256 tokens_bought, uint256 deadline, address recipient) external payable returns (uint256  eth_sold);
                              // Trade ERC20 to ETH
                              function tokenToEthSwapInput(uint256 tokens_sold, uint256 min_eth, uint256 deadline) external returns (uint256  eth_bought);
                              function tokenToEthTransferInput(uint256 tokens_sold, uint256 min_eth, uint256 deadline, address recipient) external returns (uint256  eth_bought);
                              function tokenToEthSwapOutput(uint256 eth_bought, uint256 max_tokens, uint256 deadline) external returns (uint256  tokens_sold);
                              function tokenToEthTransferOutput(uint256 eth_bought, uint256 max_tokens, uint256 deadline, address recipient) external returns (uint256  tokens_sold);
                              // Trade ERC20 to ERC20
                              function tokenToTokenSwapInput(uint256 tokens_sold, uint256 min_tokens_bought, uint256 min_eth_bought, uint256 deadline, address token_addr) external returns (uint256  tokens_bought);
                              function tokenToTokenTransferInput(uint256 tokens_sold, uint256 min_tokens_bought, uint256 min_eth_bought, uint256 deadline, address recipient, address token_addr) external returns (uint256  tokens_bought);
                              function tokenToTokenSwapOutput(uint256 tokens_bought, uint256 max_tokens_sold, uint256 max_eth_sold, uint256 deadline, address token_addr) external returns (uint256  tokens_sold);
                              function tokenToTokenTransferOutput(uint256 tokens_bought, uint256 max_tokens_sold, uint256 max_eth_sold, uint256 deadline, address recipient, address token_addr) external returns (uint256  tokens_sold);
                              // Trade ERC20 to Custom Pool
                              function tokenToExchangeSwapInput(uint256 tokens_sold, uint256 min_tokens_bought, uint256 min_eth_bought, uint256 deadline, address exchange_addr) external returns (uint256  tokens_bought);
                              function tokenToExchangeTransferInput(uint256 tokens_sold, uint256 min_tokens_bought, uint256 min_eth_bought, uint256 deadline, address recipient, address exchange_addr) external returns (uint256  tokens_bought);
                              function tokenToExchangeSwapOutput(uint256 tokens_bought, uint256 max_tokens_sold, uint256 max_eth_sold, uint256 deadline, address exchange_addr) external returns (uint256  tokens_sold);
                              function tokenToExchangeTransferOutput(uint256 tokens_bought, uint256 max_tokens_sold, uint256 max_eth_sold, uint256 deadline, address recipient, address exchange_addr) external returns (uint256  tokens_sold);
                              // ERC20 comaptibility for liquidity tokens
                              function name() external view returns (bytes32);
                              function symbol() external view returns (bytes32);
                              function decimals() external view returns (uint256);
                              function transfer(address _to, uint256 _value) external returns (bool);
                              function transferFrom(address _from, address _to, uint256 value) external returns (bool);
                              function approve(address _spender, uint256 _value) external returns (bool);
                              function allowance(address _owner, address _spender) external view returns (uint256);
                              function balanceOf(address _owner) external view returns (uint256);
                              function totalSupply() external view returns (uint256);
                              // Never use
                              function setup(address token_addr) external;
                          }
                          pragma solidity >=0.5.0 <0.8.0;
                          interface IUniswapFactory {
                              event PairCreated(
                                  address indexed token0,
                                  address indexed token1,
                                  address pair,
                                  uint256
                              );
                              function getPair(address tokenA, address tokenB)
                                  external
                                  view
                                  returns (address pair);
                              function allPairs(uint256) external view returns (address pair);
                              function allPairsLength() external view returns (uint256);
                              function feeTo() external view returns (address);
                              function feeToSetter() external view returns (address);
                              function createPair(address tokenA, address tokenB)
                                  external
                                  returns (address pair);
                              // Create Exchange
                              function createExchange(address token) external returns (address exchange);
                              // Get Exchange and Token Info
                              function getExchange(address token) external view returns (address exchange);
                              function getToken(address exchange) external view returns (address token);
                              function getTokenWithId(uint256 tokenId) external view returns (address token);
                              // Never use
                              function initializeFactory(address template) external;
                          }
                              
                              pragma solidity >=0.5.0 <0.8.0;
                          interface ICurveFi {
                              function get_virtual_price() external returns (uint256 out);
                              function add_liquidity(
                                  uint256[2] calldata amounts,
                                  uint256 deadline
                              ) external;
                              function add_liquidity(
                                  // sBTC pool
                                  uint256[3] calldata amounts,
                                  uint256 min_mint_amount
                              ) external;
                              function add_liquidity(
                                  // bUSD pool
                                  uint256[4] calldata amounts,
                                  uint256 min_mint_amount
                              ) external;
                              function get_dx(
                                  int128 i,
                                  int128 j,
                                  uint256 dy
                              ) external view returns (uint256 out);
                              function get_dx_underlying(
                                  int128 i,
                                  int128 j,
                                  uint256 dy
                              ) external view returns (uint256 out);
                              function get_dy(
                                  int128 i,
                                  int128 j,
                                  uint256 dx
                              ) external view returns (uint256 out);
                              function get_dy_underlying(
                                  int128 i,
                                  int128 j,
                                  uint256 dx
                              ) external view returns (uint256 out);
                              function exchange(
                                  int128 i,
                                  int128 j,
                                  uint256 dx,
                                  uint256 min_dy
                              ) external payable;
                              function exchange(
                                  int128 i,
                                  int128 j,
                                  uint256 dx,
                                  uint256 min_dy,
                                  uint256 deadline
                              ) external payable;
                              function exchange_underlying(
                                  int128 i,
                                  int128 j,
                                  uint256 dx,
                                  uint256 min_dy
                              ) external payable;
                              function exchange_underlying(
                                  int128 i,
                                  int128 j,
                                  uint256 dx,
                                  uint256 min_dy,
                                  uint256 deadline
                              ) external payable;
                              function remove_liquidity(
                                  uint256 _amount,
                                  uint256 deadline,
                                  uint256[2] calldata min_amounts
                              ) external;
                              function remove_liquidity_imbalance(
                                  uint256[2] calldata amounts,
                                  uint256 deadline
                              ) external;
                              function remove_liquidity_imbalance(
                                  uint256[3] calldata amounts,
                                  uint256 max_burn_amount
                              ) external;
                              function remove_liquidity(uint256 _amount, uint256[3] calldata amounts)
                                  external;
                              function remove_liquidity_imbalance(
                                  uint256[4] calldata amounts,
                                  uint256 max_burn_amount
                              ) external;
                              function remove_liquidity(uint256 _amount, uint256[4] calldata amounts)
                                  external;
                              function commit_new_parameters(
                                  int128 amplification,
                                  int128 new_fee,
                                  int128 new_admin_fee
                              ) external;
                              function apply_new_parameters() external;
                              function revert_new_parameters() external;
                              function commit_transfer_ownership(address _owner) external;
                              function apply_transfer_ownership() external;
                              function revert_transfer_ownership() external;
                              function withdraw_admin_fees() external;
                              function coins(int128 arg0) external returns (address out);
                              function underlying_coins(int128 arg0) external returns (address out);
                              function balances(int128 arg0) external returns (uint256 out);
                              function A() external returns (int128 out);
                              function fee() external returns (int128 out);
                              function admin_fee() external returns (int128 out);
                              function owner() external returns (address out);
                              function admin_actions_deadline() external returns (uint256 out);
                              function transfer_ownership_deadline() external returns (uint256 out);
                              function future_A() external returns (int128 out);
                              function future_fee() external returns (int128 out);
                              function future_admin_fee() external returns (int128 out);
                              function future_owner() external returns (address out);
                          }
                          pragma solidity ^0.6.0;
                          import "./BaseLibEIP712.sol";
                          contract AMMLibEIP712 is BaseLibEIP712 {
                              /***********************************|
                              |             Constants             |
                              |__________________________________*/
                              struct Order {
                                  address makerAddr;
                                  address takerAssetAddr;
                                  address makerAssetAddr;
                                  uint256 takerAssetAmount;
                                  uint256 makerAssetAmount;
                                  address userAddr;
                                  address payable receiverAddr;
                                  uint256 salt;
                                  uint256 deadline;
                              }
                              // keccak256("tradeWithPermit(address makerAddr,address takerAssetAddr,address makerAssetAddr,uint256 takerAssetAmount,uint256 makerAssetAmount,address userAddr,address receiverAddr,uint256 salt,uint256 deadline)");
                              bytes32 public constant TRADE_WITH_PERMIT_TYPEHASH = keccak256(
                                  abi.encodePacked(
                                      "tradeWithPermit(",
                                      "address makerAddr,",
                                      "address takerAssetAddr,",
                                      "address makerAssetAddr,",
                                      "uint256 takerAssetAmount,",
                                      "uint256 makerAssetAmount,",
                                      "address userAddr,",
                                      "address receiverAddr,",
                                      "uint256 salt,",
                                      "uint256 deadline",
                                      ")"
                                  )
                              );
                          }// SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0 <0.8.0;
                          /// @title Callback for IUniswapV3PoolActions#swap
                          /// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
                          interface IUniswapV3SwapCallback {
                              /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
                              /// @dev In the implementation you must pay the pool tokens owed for the swap.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
                              /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
                              /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
                              function uniswapV3SwapCallback(
                                  int256 amount0Delta,
                                  int256 amount1Delta,
                                  bytes calldata data
                              ) external;
                          }pragma solidity ^0.6.0;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
                          import "./interfaces/IWeth.sol";
                          import "./pmm/mmp/Ownable.sol";
                          import "./pmm/0xLibs/LibDecoder.sol";
                          interface IIMBTC {
                              function burn(uint256 amount, bytes calldata data) external;
                          }
                          interface IWBTC {
                              function burn(uint256 value) external;
                          }
                          contract MarketMakerProxy is 
                              Ownable,
                              LibDecoder
                          {
                              using SafeERC20 for IERC20;
                              string public constant version = "5.0.0";
                              uint256 constant MAX_UINT = 2**256 - 1;
                              address public SIGNER;
                              // auto withdraw weth to eth
                              address public WETH_ADDR;
                              address public withdrawer;
                              mapping (address => bool) public isWithdrawWhitelist;
                              modifier onlyWithdrawer() {
                                  require(
                                      msg.sender == withdrawer,
                                      "MarketMakerProxy: only contract withdrawer"
                                  );
                                  _;
                              }
                              constructor () public {
                                  owner = msg.sender;
                                  operator = msg.sender;
                              }
                              receive() external payable {}
                              // Manage
                              function setSigner(address _signer) public onlyOperator {
                                  SIGNER = _signer;
                              }
                              function setConfig(address _weth) public onlyOperator {
                                  WETH_ADDR = _weth;
                              }
                              function setWithdrawer(address _withdrawer) public onlyOperator {
                                  withdrawer = _withdrawer;
                              }
                              function setAllowance(address[] memory token_addrs, address spender) public onlyOperator {
                                  for (uint i = 0; i < token_addrs.length; i++) {
                                      address token = token_addrs[i];
                                      IERC20(token).safeApprove(spender, MAX_UINT);
                                  }
                              }
                              function closeAllowance(address[] memory token_addrs, address spender) public onlyOperator {
                                  for (uint i = 0; i < token_addrs.length; i++) {
                                      address token = token_addrs[i];
                                      IERC20(token).safeApprove(spender, 0);
                                  }
                              }
                              function registerWithdrawWhitelist(address _addr, bool _add) public onlyOperator {
                                  isWithdrawWhitelist[_addr] = _add;
                              }
                              function withdraw(address token, address payable to, uint256 amount) public onlyWithdrawer {
                                  require(
                                      isWithdrawWhitelist[to],
                                      "MarketMakerProxy: not in withdraw whitelist"
                                  );
                                  if(token == WETH_ADDR) {
                                      IWETH(WETH_ADDR).withdraw(amount);
                                      to.transfer(amount);
                                  } else {
                                      IERC20(token).safeTransfer(to , amount);
                                  }
                              }
                              function withdrawETH(address payable to, uint256 amount) public onlyWithdrawer {
                                  require(
                                      isWithdrawWhitelist[to],
                                      "MarketMakerProxy: not in withdraw whitelist"
                                  );
                                  to.transfer(amount);
                              }
                              function isValidSignature(bytes32 orderHash, bytes memory signature) public view returns (bytes32) {
                                  require(
                                      SIGNER == _ecrecoverAddress(orderHash, signature),
                                      "MarketMakerProxy: invalid signature"
                                  );
                                  return keccak256("isValidWalletSignature(bytes32,address,bytes)");
                              }
                              function _ecrecoverAddress(bytes32 orderHash, bytes memory signature) internal pure returns (address) {
                                  (uint8 v, bytes32 r, bytes32 s) = decodeMmSignature(signature);
                                  return ecrecover(
                                      keccak256(
                                          abi.encodePacked(
                                              "\\x19Ethereum Signed Message:\
                          32",
                                              orderHash
                                          )),
                                      v, r, s
                                  );
                              }
                          }
                          pragma solidity ^0.6.0;
                          contract Ownable {
                            address public owner;
                            address public operator;
                            constructor ()
                              public
                            {
                              owner = msg.sender;
                            }
                            modifier onlyOwner() {
                              require(
                                msg.sender == owner,
                                "Ownable: only contract owner"
                              );
                              _;
                            }
                            modifier onlyOperator() {
                              require(
                                msg.sender == operator,
                                "Ownable: only contract operator"
                              );
                              _;
                            }
                            function transferOwnership(address newOwner)
                              public
                              onlyOwner
                            {
                              if (newOwner != address(0)) {
                                owner = newOwner;
                              }
                            }
                            function setOperator(address newOperator)
                              public
                              onlyOwner 
                            {
                              operator = newOperator;
                            }
                          }pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          import "@openzeppelin/contracts/math/SafeMath.sol";
                          import "./interfaces/IUniswapExchange.sol";
                          import "./interfaces/IUniswapFactory.sol";
                          import "./interfaces/IUniswapRouterV2.sol";
                          import "./interfaces/ICurveFi.sol";
                          import "./interfaces/IWeth.sol";
                          import "./interfaces/IPermanentStorage.sol";
                          import "./interfaces/IUniswapV3Quoter.sol";
                          import "./utils/LibBytes.sol";
                          /// This contract is designed to be called off-chain.
                          /// At T1, 4 requests would be made in order to get quote, which is for Uniswap v2, v3, Sushiswap and others.
                          /// For those source without path design, we can find best out amount in this contract.
                          /// For Uniswap and Sushiswap, best path would be calculated off-chain, we only verify out amount in this contract.
                          contract AMMQuoter {
                              using SafeMath for uint256;
                              using LibBytes for bytes;
                              /* Constants */
                              string public constant version = "5.2.0";
                              address private constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant ZERO_ADDRESS = address(0);
                              address public constant UNISWAP_V2_ROUTER_02_ADDRESS = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
                              address public constant UNISWAP_V3_ROUTER_ADDRESS = 0xE592427A0AEce92De3Edee1F18E0157C05861564;
                              address public constant UNISWAP_V3_QUOTER_ADDRESS = 0xb27308f9F90D607463bb33eA1BeBb41C27CE5AB6;
                              address public constant SUSHISWAP_ROUTER_ADDRESS = 0xd9e1cE17f2641f24aE83637ab66a2cca9C378B9F;
                              address public immutable weth;
                              IPermanentStorage public immutable permStorage;
                              struct GroupedVars {
                                  address makerAddr;
                                  address takerAssetAddr;
                                  address makerAssetAddr;
                                  uint256 takerAssetAmount;
                                  uint256 makerAssetAmount;
                                  address[] path;
                              }
                              event CurveTokenAdded(
                                  address indexed makerAddress,
                                  address indexed assetAddress,
                                  int128 index
                              );
                              constructor (IPermanentStorage _permStorage, address _weth) public {
                                  permStorage = _permStorage;
                                  weth = _weth;
                              }
                              function isETH(address assetAddress) public pure returns (bool) {
                                  return (assetAddress == ZERO_ADDRESS || assetAddress == ETH_ADDRESS);
                              }
                              function getMakerOutAmountWithPath(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _takerAssetAmount,
                                  address[] calldata _path,
                                  bytes memory _makerSpecificData
                              )
                                  public
                                  returns (uint256 makerAssetAmount)
                              {
                                  GroupedVars memory vars;
                                  vars.makerAddr = _makerAddr;
                                  vars.takerAssetAddr = _takerAssetAddr;
                                  vars.makerAssetAddr = _makerAssetAddr;
                                  vars.takerAssetAmount = _takerAssetAmount;
                                  vars.path = _path;
                                  if (vars.makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      vars.makerAddr == SUSHISWAP_ROUTER_ADDRESS) {
                                      IUniswapRouterV2 router = IUniswapRouterV2(vars.makerAddr);
                                      uint256[] memory amounts = router.getAmountsOut(vars.takerAssetAmount, vars.path);
                                      makerAssetAmount = amounts[amounts.length-1];
                                  } else if (vars.makerAddr == UNISWAP_V3_ROUTER_ADDRESS) {
                                      IUniswapV3Quoter quoter = IUniswapV3Quoter(UNISWAP_V3_QUOTER_ADDRESS);
                                      // swapType:
                                      // 1: exactInputSingle, 2: exactInput, 3: exactOuputSingle, 4: exactOutput
                                      uint8 swapType = uint8(uint256(_makerSpecificData.readBytes32(0)));
                                      if (swapType == 1) {
                                          address v3TakerInternalAsset = isETH(vars.takerAssetAddr) ? weth : vars.takerAssetAddr;
                                          address v3MakerInternalAsset = isETH(vars.makerAssetAddr) ? weth : vars.makerAssetAddr;
                                          (, uint24 poolFee) = abi.decode(_makerSpecificData, (uint8, uint24));
                                          makerAssetAmount = quoter.quoteExactInputSingle(v3TakerInternalAsset, v3MakerInternalAsset, poolFee, vars.takerAssetAmount, 0);
                                      } else if (swapType == 2) {
                                          (, bytes memory path) = abi.decode(_makerSpecificData, (uint8, bytes));
                                          makerAssetAmount = quoter.quoteExactInput(path, vars.takerAssetAmount);
                                      } else {
                                          revert("AMMQuoter: Invalid UniswapV3 swap type");
                                      }
                                  } else {
                                      address curveTakerIntenalAsset = isETH(vars.takerAssetAddr) ? ETH_ADDRESS : vars.takerAssetAddr;
                                      address curveMakerIntenalAsset = isETH(vars.makerAssetAddr) ? ETH_ADDRESS : vars.makerAssetAddr;
                                      (int128 fromTokenCurveIndex, int128 toTokenCurveIndex, uint16 swapMethod,) = permStorage.getCurvePoolInfo(vars.makerAddr, curveTakerIntenalAsset, curveMakerIntenalAsset);
                                      if (fromTokenCurveIndex > 0 && toTokenCurveIndex > 0) {
                                          require(swapMethod != 0, "AMMQuoter: swap method not registered");
                                          // Substract index by 1 because indices stored in `permStorage` starts from 1
                                          fromTokenCurveIndex = fromTokenCurveIndex - 1;
                                          toTokenCurveIndex = toTokenCurveIndex - 1;
                                          ICurveFi curve = ICurveFi(vars.makerAddr);
                                          if (swapMethod == 1) {
                                              makerAssetAmount = curve.get_dy(fromTokenCurveIndex, toTokenCurveIndex, vars.takerAssetAmount).sub(1);
                                          } else if (swapMethod == 2) {
                                              makerAssetAmount = curve.get_dy_underlying(fromTokenCurveIndex, toTokenCurveIndex, vars.takerAssetAmount).sub(1);
                                          }
                                      } else {
                                          revert("AMMQuoter: Unsupported makerAddr");
                                      }
                                  }
                                  return makerAssetAmount;
                              }
                              function getMakerOutAmount(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _takerAssetAmount
                              )
                                  public
                                  view
                                  returns (uint256)
                              {
                                  uint256 makerAssetAmount;
                                  if (_makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      _makerAddr == SUSHISWAP_ROUTER_ADDRESS) {
                                      IUniswapRouterV2 router = IUniswapRouterV2(_makerAddr);
                                      address[] memory path = new address[](2);
                                      if (isETH(_takerAssetAddr)) {
                                          path[0] = weth;
                                          path[1] = _makerAssetAddr;
                                      } else if (isETH(_makerAssetAddr)) {
                                          path[0] = _takerAssetAddr;
                                          path[1] = weth;
                                      } else {
                                          path[0] = _takerAssetAddr;
                                          path[1] = _makerAssetAddr;
                                      }
                                      uint256[] memory amounts = router.getAmountsOut(_takerAssetAmount, path);
                                      makerAssetAmount = amounts[1];
                                  } else {
                                      address curveTakerIntenalAsset = isETH(_takerAssetAddr) ? ETH_ADDRESS : _takerAssetAddr;
                                      address curveMakerIntenalAsset = isETH(_makerAssetAddr) ? ETH_ADDRESS : _makerAssetAddr;
                                      (int128 fromTokenCurveIndex, int128 toTokenCurveIndex, uint16 swapMethod,) = permStorage.getCurvePoolInfo(_makerAddr, curveTakerIntenalAsset, curveMakerIntenalAsset);
                                      if (fromTokenCurveIndex > 0 && toTokenCurveIndex > 0) {
                                          require(swapMethod != 0, "AMMQuoter: swap method not registered");
                                          // Substract index by 1 because indices stored in `permStorage` starts from 1
                                          fromTokenCurveIndex = fromTokenCurveIndex - 1;
                                          toTokenCurveIndex = toTokenCurveIndex - 1;
                                          ICurveFi curve = ICurveFi(_makerAddr);
                                          if (swapMethod == 1) {
                                              makerAssetAmount = curve.get_dy(fromTokenCurveIndex, toTokenCurveIndex, _takerAssetAmount).sub(1);
                                          } else if (swapMethod == 2) {
                                              makerAssetAmount = curve.get_dy_underlying(fromTokenCurveIndex, toTokenCurveIndex, _takerAssetAmount).sub(1);
                                          }
                                      } else {
                                          revert("AMMQuoter: Unsupported makerAddr");
                                      }
                                  }
                                  return makerAssetAmount;
                              }
                              /// @dev This function is designed for finding best out amount among AMM makers other than Uniswap and Sushiswap
                              function getBestOutAmount(
                                  address[] calldata _makerAddresses,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _takerAssetAmount
                              )
                                  external
                                  view
                                  returns (address bestMaker, uint256 bestAmount)
                              {
                                  bestAmount = 0;
                                  uint256 poolLength = _makerAddresses.length;
                                  for (uint256 i = 0; i < poolLength; i++) {
                                      address makerAddress = _makerAddresses[i];
                                      uint256 makerAssetAmount = getMakerOutAmount(makerAddress, _takerAssetAddr, _makerAssetAddr, _takerAssetAmount);
                                      if (makerAssetAmount > bestAmount) {
                                          bestAmount = makerAssetAmount;
                                          bestMaker = makerAddress;
                                      }
                                  }
                                  return (bestMaker, bestAmount);
                              }
                              function getTakerInAmountWithPath(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _makerAssetAmount,
                                  address[] calldata _path,
                                  bytes memory _makerSpecificData
                              )
                                  public
                                  returns (uint256 takerAssetAmount)
                              {
                                  GroupedVars memory vars;
                                  vars.makerAddr = _makerAddr;
                                  vars.takerAssetAddr = _takerAssetAddr;
                                  vars.makerAssetAddr = _makerAssetAddr;
                                  vars.makerAssetAmount = _makerAssetAmount;
                                  vars.path = _path;
                                  if (vars.makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      vars.makerAddr == SUSHISWAP_ROUTER_ADDRESS) {
                                      IUniswapRouterV2 router = IUniswapRouterV2(vars.makerAddr);
                                      uint256[] memory amounts = router.getAmountsIn(vars.makerAssetAmount, _path);
                                      takerAssetAmount = amounts[0];
                                  } else if (vars.makerAddr == UNISWAP_V3_ROUTER_ADDRESS) {
                                      IUniswapV3Quoter quoter = IUniswapV3Quoter(UNISWAP_V3_QUOTER_ADDRESS);
                                      // swapType:
                                      // 1: exactInputSingle, 2: exactInput, 3: exactOuputSingle, 4: exactOutput
                                      uint8 swapType = uint8(uint256(_makerSpecificData.readBytes32(0)));
                                      if (swapType == 3) {
                                          address v3TakerInternalAsset = isETH(vars.takerAssetAddr) ? weth : vars.takerAssetAddr;
                                          address v3MakerInternalAsset = isETH(vars.makerAssetAddr) ? weth : vars.makerAssetAddr;
                                          (, uint24 poolFee) = abi.decode(_makerSpecificData, (uint8, uint24));
                                          takerAssetAmount = quoter.quoteExactOutputSingle(v3TakerInternalAsset, v3MakerInternalAsset, poolFee, vars.makerAssetAmount, 0);
                                      } else if (swapType == 4) {
                                          (, bytes memory path) = abi.decode(_makerSpecificData, (uint8, bytes));
                                          takerAssetAmount = quoter.quoteExactOutput(path, vars.makerAssetAmount);
                                      } else {
                                          revert("AMMQuoter: Invalid UniswapV3 swap type");
                                      }
                                  } else {
                                      address curveTakerIntenalAsset = isETH(vars.takerAssetAddr) ? ETH_ADDRESS : vars.takerAssetAddr;
                                      address curveMakerIntenalAsset = isETH(vars.makerAssetAddr) ? ETH_ADDRESS : vars.makerAssetAddr;
                                      (int128 fromTokenCurveIndex, int128 toTokenCurveIndex, uint16 swapMethod, bool supportGetDx) = permStorage.getCurvePoolInfo(vars.makerAddr, curveTakerIntenalAsset, curveMakerIntenalAsset);
                                      if (fromTokenCurveIndex > 0 && toTokenCurveIndex > 0) {
                                          require(swapMethod != 0, "AMMQuoter: swap method not registered");
                                          // Substract index by 1 because indices stored in `permStorage` starts from 1
                                          fromTokenCurveIndex = fromTokenCurveIndex - 1;
                                          toTokenCurveIndex = toTokenCurveIndex - 1;
                                          ICurveFi curve = ICurveFi(vars.makerAddr);
                                          if (supportGetDx) {
                                              if (swapMethod == 1) {
                                                  takerAssetAmount = curve.get_dx(fromTokenCurveIndex, toTokenCurveIndex, vars.makerAssetAmount);
                                              } else if (swapMethod == 2) {
                                                  takerAssetAmount = curve.get_dx_underlying(fromTokenCurveIndex, toTokenCurveIndex, vars.makerAssetAmount);
                                              }
                                          } else {
                                              if (swapMethod == 1) {
                                                  // does not support get_dx_underlying, try to get an estimated rate here
                                                  takerAssetAmount = curve.get_dy(toTokenCurveIndex, fromTokenCurveIndex, vars.makerAssetAmount);
                                              } else if (swapMethod == 2) {
                                                  takerAssetAmount = curve.get_dy_underlying(toTokenCurveIndex, fromTokenCurveIndex, vars.makerAssetAmount);
                                              }
                                          }
                                      } else {
                                          revert("AMMQuoter: Unsupported makerAddr");
                                      }
                                  }
                                  return takerAssetAmount;
                              }
                              function getTakerInAmount(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _makerAssetAmount
                              )
                                  public
                                  view
                                  returns (uint256)
                              {
                                  uint256 takerAssetAmount;
                                  if (_makerAddr == UNISWAP_V2_ROUTER_02_ADDRESS ||
                                      _makerAddr == SUSHISWAP_ROUTER_ADDRESS) {
                                      IUniswapRouterV2 router = IUniswapRouterV2(_makerAddr);
                                      address[] memory path = new address[](2);
                                      if (isETH(_takerAssetAddr)) {
                                          path[0] = weth;
                                          path[1] = _makerAssetAddr;
                                      } else if (isETH(_makerAssetAddr)) {
                                          path[0] = _takerAssetAddr;
                                          path[1] = weth;
                                      } else {
                                          path[0] = _takerAssetAddr;
                                          path[1] = _makerAssetAddr;
                                      }
                                      uint256[] memory amounts = router.getAmountsIn(_makerAssetAmount, path);
                                      takerAssetAmount = amounts[0];
                                  } else {
                                      address curveTakerIntenalAsset = isETH(_takerAssetAddr) ? ETH_ADDRESS : _takerAssetAddr;
                                      address curveMakerIntenalAsset = isETH(_makerAssetAddr) ? ETH_ADDRESS : _makerAssetAddr;
                                      (int128 fromTokenCurveIndex, int128 toTokenCurveIndex, uint16 swapMethod, bool supportGetDx) = permStorage.getCurvePoolInfo(_makerAddr, curveTakerIntenalAsset, curveMakerIntenalAsset);
                                      if (fromTokenCurveIndex > 0 && toTokenCurveIndex > 0) {
                                          require(swapMethod != 0, "AMMQuoter: swap method not registered");
                                          // Substract index by 1 because indices stored in `permStorage` starts from 1
                                          fromTokenCurveIndex = fromTokenCurveIndex - 1;
                                          toTokenCurveIndex = toTokenCurveIndex - 1;
                                          ICurveFi curve = ICurveFi(_makerAddr);
                                          if (supportGetDx) {
                                              if (swapMethod == 1) {
                                                  takerAssetAmount = curve.get_dx(fromTokenCurveIndex, toTokenCurveIndex, _makerAssetAmount);
                                              } else if (swapMethod == 2) {
                                                  takerAssetAmount = curve.get_dx_underlying(fromTokenCurveIndex, toTokenCurveIndex, _makerAssetAmount);
                                              }
                                          } else {
                                              if (swapMethod == 1) {
                                                  // does not support get_dx_underlying, try to get an estimated rate here
                                                  takerAssetAmount = curve.get_dy(toTokenCurveIndex, fromTokenCurveIndex, _makerAssetAmount);
                                              } else if (swapMethod == 2) {
                                                  takerAssetAmount = curve.get_dy_underlying(toTokenCurveIndex, fromTokenCurveIndex, _makerAssetAmount);
                                              }
                                          }
                                      } else {
                                          revert("AMMQuoter: Unsupported makerAddr");
                                      }
                                  }
                                  return takerAssetAmount;
                              }
                              /// @dev This function is designed for finding best in amount among AMM makers other than Uniswap and Sushiswap
                              function getBestInAmount(
                                  address[] calldata _makerAddresses,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr,
                                  uint256 _makerAssetAmount
                              )
                                  external
                                  view
                                  returns (address bestMaker, uint256 bestAmount)
                              {
                                  bestAmount = 2**256 - 1;
                                  uint256 poolLength = _makerAddresses.length;
                                  for (uint256 i = 0; i < poolLength; i++) {
                                      address makerAddress = _makerAddresses[i];
                                      uint256 takerAssetAmount = getTakerInAmount(makerAddress, _takerAssetAddr, _makerAssetAddr, _makerAssetAmount);
                                      if (takerAssetAmount < bestAmount) {
                                          bestAmount = takerAssetAmount;
                                          bestMaker = makerAddress;
                                      }
                                  }
                                  return (bestMaker, bestAmount);
                              }
                          }
                          pragma solidity ^0.6.0;
                          pragma experimental ABIEncoderV2;
                          /// @title Quoter Interface
                          /// @notice Supports quoting the calculated amounts from exact input or exact output swaps
                          /// @dev These functions are not marked view because they rely on calling non-view functions and reverting
                          /// to compute the result. They are also not gas efficient and should not be called on-chain.
                          interface IUniswapV3Quoter {
                              /// @notice Returns the amount out received for a given exact input swap without executing the swap
                              /// @param path The path of the swap, i.e. each token pair and the pool fee
                              /// @param amountIn The amount of the first token to swap
                              /// @return amountOut The amount of the last token that would be received
                              function quoteExactInput(bytes memory path, uint256 amountIn) external returns (uint256 amountOut);
                              /// @notice Returns the amount out received for a given exact input but for a swap of a single pool
                              /// @param tokenIn The token being swapped in
                              /// @param tokenOut The token being swapped out
                              /// @param fee The fee of the token pool to consider for the pair
                              /// @param amountIn The desired input amount
                              /// @param sqrtPriceLimitX96 The price limit of the pool that cannot be exceeded by the swap
                              /// @return amountOut The amount of `tokenOut` that would be received
                              function quoteExactInputSingle(
                                  address tokenIn,
                                  address tokenOut,
                                  uint24 fee,
                                  uint256 amountIn,
                                  uint160 sqrtPriceLimitX96
                              ) external returns (uint256 amountOut);
                              /// @notice Returns the amount in required for a given exact output swap without executing the swap
                              /// @param path The path of the swap, i.e. each token pair and the pool fee. Path must be provided in reverse order
                              /// @param amountOut The amount of the last token to receive
                              /// @return amountIn The amount of first token required to be paid
                              function quoteExactOutput(bytes memory path, uint256 amountOut) external returns (uint256 amountIn);
                              /// @notice Returns the amount in required to receive the given exact output amount but for a swap of a single pool
                              /// @param tokenIn The token being swapped in
                              /// @param tokenOut The token being swapped out
                              /// @param fee The fee of the token pool to consider for the pair
                              /// @param amountOut The desired output amount
                              /// @param sqrtPriceLimitX96 The price limit of the pool that cannot be exceeded by the swap
                              /// @return amountIn The amount required as the input for the swap in order to receive `amountOut`
                              function quoteExactOutputSingle(
                                  address tokenIn,
                                  address tokenOut,
                                  uint24 fee,
                                  uint256 amountOut,
                                  uint160 sqrtPriceLimitX96
                              ) external returns (uint256 amountIn);
                          }
                          pragma solidity ^0.6.0;
                          import "./interfaces/IHasBlackListERC20Token.sol";
                          import "./interfaces/ISpender.sol";
                          contract SpenderSimulation {
                              ISpender public immutable spender;
                              mapping(address => bool) public hasBlackListERC20Tokens;
                              modifier checkBlackList(address _tokenAddr, address _user) {
                                  if (hasBlackListERC20Tokens[_tokenAddr]) {
                                      IHasBlackListERC20Token hasBlackListERC20Token = IHasBlackListERC20Token(_tokenAddr);
                                      require(!hasBlackListERC20Token.isBlackListed(_user), "SpenderSimulation: user in token's blacklist");
                                  }
                                  _;
                              }
                              /************************************************************
                              *                       Constructor                         *
                              *************************************************************/
                              constructor (ISpender _spender, address[] memory _hasBlackListERC20Tokens) public {
                                  spender = _spender;
                                  for (uint256 i = 0; i < _hasBlackListERC20Tokens.length; i++) {
                                      hasBlackListERC20Tokens[_hasBlackListERC20Tokens[i]] = true;
                                  }
                              }
                              /************************************************************
                              *                    Helper functions                       *
                              *************************************************************/
                              /// @dev Spend tokens on user's behalf but reverts if succeed.
                              /// This is only intended to be run off-chain to check if the transfer will succeed.
                              /// @param _user The user to spend token from.
                              /// @param _tokenAddr The address of the token.
                              /// @param _amount Amount to spend.
                              function simulate(address _user, address _tokenAddr, uint256 _amount) external checkBlackList(_tokenAddr, _user) {
                                  spender.spendFromUser(_user, _tokenAddr, _amount);
                                  // All checks passed: revert with success reason string
                                  revert("SpenderSimulation: transfer simulation success");
                              }
                          }
                          pragma solidity ^0.6.0;
                          import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                          interface IHasBlackListERC20Token is IERC20 {
                              function isBlackListed(address user) external returns (bool);
                              function addBlackList(address user) external;
                              function removeBlackList(address user) external;
                          }// SPDX-License-Identifier: MIT
                          pragma solidity ^0.6.0;
                          import "./upgrade_proxy/TransparentUpgradeableProxy.sol";
                          contract Tokenlon is TransparentUpgradeableProxy {
                              constructor(address _logic, address _admin, bytes memory _data) public payable TransparentUpgradeableProxy(_logic, _admin, _data) {}
                          }// SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          import "./UpgradeableProxy.sol";
                          /**
                           * @dev This contract implements a proxy that is upgradeable by an admin.
                           * 
                           * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                           * clashing], which can potentially be used in an attack, this contract uses the
                           * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                           * things that go hand in hand:
                           * 
                           * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                           * that call matches one of the admin functions exposed by the proxy itself.
                           * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                           * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                           * "admin cannot fallback to proxy target".
                           * 
                           * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                           * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                           * to sudden errors when trying to call a function from the proxy implementation.
                           * 
                           * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                           * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
                           */
                          contract TransparentUpgradeableProxy is UpgradeableProxy {
                              /**
                               * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                               * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
                               */
                              constructor(address _logic, address _admin, bytes memory _data) public payable UpgradeableProxy(_logic, _data) {
                                  assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                                  _setAdmin(_admin);
                              }
                              /**
                               * @dev Emitted when the admin account has changed.
                               */
                              event AdminChanged(address previousAdmin, address newAdmin);
                              /**
                               * @dev Storage slot with the admin of the contract.
                               * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                               * validated in the constructor.
                               */
                              bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                              /**
                               * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                               */
                              modifier ifAdmin() {
                                  if (msg.sender == _admin()) {
                                      _;
                                  } else {
                                      _fallback();
                                  }
                              }
                              /**
                               * @dev Returns the current admin.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
                               * 
                               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                               * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                               */
                              function admin() external ifAdmin returns (address) {
                                  return _admin();
                              }
                              /**
                               * @dev Returns the current implementation.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
                               * 
                               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                               * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                               */
                              function implementation() external ifAdmin returns (address) {
                                  return _implementation();
                              }
                              /**
                               * @dev Changes the admin of the proxy.
                               * 
                               * Emits an {AdminChanged} event.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
                               */
                              function changeAdmin(address newAdmin) external ifAdmin {
                                  require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
                                  emit AdminChanged(_admin(), newAdmin);
                                  _setAdmin(newAdmin);
                              }
                              /**
                               * @dev Upgrade the implementation of the proxy.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
                               */
                              function upgradeTo(address newImplementation) external ifAdmin {
                                  _upgradeTo(newImplementation);
                              }
                              /**
                               * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                               * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                               * proxied contract.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
                               */
                              function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                                  _upgradeTo(newImplementation);
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success,) = newImplementation.delegatecall(data);
                                  require(success);
                              }
                              /**
                               * @dev Returns the current admin.
                               */
                              function _admin() internal view returns (address adm) {
                                  bytes32 slot = _ADMIN_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      adm := sload(slot)
                                  }
                              }
                              /**
                               * @dev Stores a new address in the EIP1967 admin slot.
                               */
                              function _setAdmin(address newAdmin) private {
                                  bytes32 slot = _ADMIN_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      sstore(slot, newAdmin)
                                  }
                              }
                              /**
                               * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
                               */
                              function _beforeFallback() internal override virtual {
                                  require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                  super._beforeFallback();
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          import "@openzeppelin/contracts/utils/Address.sol";
                          import "./Proxy.sol";
                          /**
                           * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                           * implementation address that can be changed. This address is stored in storage in the location specified by
                           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                           * implementation behind the proxy.
                           * 
                           * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see
                           * {TransparentUpgradeableProxy}.
                           */
                          contract UpgradeableProxy is Proxy {
                              /**
                               * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                               * 
                               * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                               * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                               */
                              constructor(address _logic, bytes memory _data) public payable {
                                  assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                  _setImplementation(_logic);
                                  if(_data.length > 0) {
                                      // solhint-disable-next-line avoid-low-level-calls
                                      (bool success,) = _logic.delegatecall(_data);
                                      require(success);
                                  }
                              }
                              /**
                               * @dev Emitted when the implementation is upgraded.
                               */
                              event Upgraded(address indexed implementation);
                              /**
                               * @dev Storage slot with the address of the current implementation.
                               * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                               * validated in the constructor.
                               */
                              bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                              /**
                               * @dev Returns the current implementation address.
                               */
                              function _implementation() internal override view returns (address impl) {
                                  bytes32 slot = _IMPLEMENTATION_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      impl := sload(slot)
                                  }
                              }
                              /**
                               * @dev Upgrades the proxy to a new implementation.
                               * 
                               * Emits an {Upgraded} event.
                               */
                              function _upgradeTo(address newImplementation) internal {
                                  _setImplementation(newImplementation);
                                  emit Upgraded(newImplementation);
                              }
                              /**
                               * @dev Stores a new address in the EIP1967 implementation slot.
                               */
                              function _setImplementation(address newImplementation) private {
                                  require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");
                                  bytes32 slot = _IMPLEMENTATION_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      sstore(slot, newImplementation)
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                           * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                           * be specified by overriding the virtual {_implementation} function.
                           * 
                           * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                           * different contract through the {_delegate} function.
                           * 
                           * The success and return data of the delegated call will be returned back to the caller of the proxy.
                           */
                          abstract contract Proxy {
                              /**
                               * @dev Delegates the current call to `implementation`.
                               * 
                               * This function does not return to its internall call site, it will return directly to the external caller.
                               */
                              function _delegate(address implementation) internal {
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      // Copy msg.data. We take full control of memory in this inline assembly
                                      // block because it will not return to Solidity code. We overwrite the
                                      // Solidity scratch pad at memory position 0.
                                      calldatacopy(0, 0, calldatasize())
                                      // Call the implementation.
                                      // out and outsize are 0 because we don't know the size yet.
                                      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                      // Copy the returned data.
                                      returndatacopy(0, 0, returndatasize())
                                      switch result
                                      // delegatecall returns 0 on error.
                                      case 0 { revert(0, returndatasize()) }
                                      default { return(0, returndatasize()) }
                                  }
                              }
                              /**
                               * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                               * and {_fallback} should delegate.
                               */
                              function _implementation() internal virtual view returns (address);
                              /**
                               * @dev Delegates the current call to the address returned by `_implementation()`.
                               * 
                               * This function does not return to its internall call site, it will return directly to the external caller.
                               */
                              function _fallback() internal {
                                  _beforeFallback();
                                  _delegate(_implementation());
                              }
                              /**
                               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                               * function in the contract matches the call data.
                               */
                              fallback () payable external {
                                  _fallback();
                              }
                              /**
                               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                               * is empty.
                               */
                              receive () payable external {
                                  _fallback();
                              }
                              /**
                               * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                               * call, or as part of the Solidity `fallback` or `receive` functions.
                               * 
                               * If overriden should call `super._beforeFallback()`.
                               */
                              function _beforeFallback() internal virtual {
                              }
                          }
                          

                          File 3 of 13: Uni
                          /**
                           *Submitted for verification at Etherscan.io on 2020-09-15
                          */
                          
                          pragma solidity ^0.5.16;
                          pragma experimental ABIEncoderV2;
                          
                          // From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/Math.sol
                          // Subject to the MIT license.
                          
                          /**
                           * @dev Wrappers over Solidity's arithmetic operations with added overflow
                           * checks.
                           *
                           * Arithmetic operations in Solidity wrap on overflow. This can easily result
                           * in bugs, because programmers usually assume that an overflow raises an
                           * error, which is the standard behavior in high level programming languages.
                           * `SafeMath` restores this intuition by reverting the transaction when an
                           * operation overflows.
                           *
                           * Using this library instead of the unchecked operations eliminates an entire
                           * class of bugs, so it's recommended to use it always.
                           */
                          library SafeMath {
                              /**
                               * @dev Returns the addition of two unsigned integers, reverting on overflow.
                               *
                               * Counterpart to Solidity's `+` operator.
                               *
                               * Requirements:
                               * - Addition cannot overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a, "SafeMath: addition overflow");
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the addition of two unsigned integers, reverting with custom message on overflow.
                               *
                               * Counterpart to Solidity's `+` operator.
                               *
                               * Requirements:
                               * - Addition cannot overflow.
                               */
                              function add(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a, errorMessage);
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting on underflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               * - Subtraction cannot underflow.
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return sub(a, b, "SafeMath: subtraction underflow");
                              }
                          
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting with custom message on underflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               * - Subtraction cannot underflow.
                               */
                              function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b <= a, errorMessage);
                                  uint256 c = a - b;
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the multiplication of two unsigned integers, reverting on overflow.
                               *
                               * Counterpart to Solidity's `*` operator.
                               *
                               * Requirements:
                               * - Multiplication cannot overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                          
                                  uint256 c = a * b;
                                  require(c / a == b, "SafeMath: multiplication overflow");
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the multiplication of two unsigned integers, reverting on overflow.
                               *
                               * Counterpart to Solidity's `*` operator.
                               *
                               * Requirements:
                               * - Multiplication cannot overflow.
                               */
                              function mul(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                          
                                  uint256 c = a * b;
                                  require(c / a == b, errorMessage);
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the integer division of two unsigned integers.
                               * Reverts on division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return div(a, b, "SafeMath: division by zero");
                              }
                          
                              /**
                               * @dev Returns the integer division of two unsigned integers.
                               * Reverts with custom message on division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  // Solidity only automatically asserts when dividing by 0
                                  require(b > 0, errorMessage);
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * Reverts when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return mod(a, b, "SafeMath: modulo by zero");
                              }
                          
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * Reverts with custom message when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b != 0, errorMessage);
                                  return a % b;
                              }
                          }
                          
                          contract Uni {
                              /// @notice EIP-20 token name for this token
                              string public constant name = "Uniswap";
                          
                              /// @notice EIP-20 token symbol for this token
                              string public constant symbol = "UNI";
                          
                              /// @notice EIP-20 token decimals for this token
                              uint8 public constant decimals = 18;
                          
                              /// @notice Total number of tokens in circulation
                              uint public totalSupply = 1_000_000_000e18; // 1 billion Uni
                          
                              /// @notice Address which may mint new tokens
                              address public minter;
                          
                              /// @notice The timestamp after which minting may occur
                              uint public mintingAllowedAfter;
                          
                              /// @notice Minimum time between mints
                              uint32 public constant minimumTimeBetweenMints = 1 days * 365;
                          
                              /// @notice Cap on the percentage of totalSupply that can be minted at each mint
                              uint8 public constant mintCap = 2;
                          
                              /// @notice Allowance amounts on behalf of others
                              mapping (address => mapping (address => uint96)) internal allowances;
                          
                              /// @notice Official record of token balances for each account
                              mapping (address => uint96) internal balances;
                          
                              /// @notice A record of each accounts delegate
                              mapping (address => address) public delegates;
                          
                              /// @notice A checkpoint for marking number of votes from a given block
                              struct Checkpoint {
                                  uint32 fromBlock;
                                  uint96 votes;
                              }
                          
                              /// @notice A record of votes checkpoints for each account, by index
                              mapping (address => mapping (uint32 => Checkpoint)) public checkpoints;
                          
                              /// @notice The number of checkpoints for each account
                              mapping (address => uint32) public numCheckpoints;
                          
                              /// @notice The EIP-712 typehash for the contract's domain
                              bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)");
                          
                              /// @notice The EIP-712 typehash for the delegation struct used by the contract
                              bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)");
                          
                              /// @notice The EIP-712 typehash for the permit struct used by the contract
                              bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
                          
                              /// @notice A record of states for signing / validating signatures
                              mapping (address => uint) public nonces;
                          
                              /// @notice An event thats emitted when the minter address is changed
                              event MinterChanged(address minter, address newMinter);
                          
                              /// @notice An event thats emitted when an account changes its delegate
                              event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate);
                          
                              /// @notice An event thats emitted when a delegate account's vote balance changes
                              event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance);
                          
                              /// @notice The standard EIP-20 transfer event
                              event Transfer(address indexed from, address indexed to, uint256 amount);
                          
                              /// @notice The standard EIP-20 approval event
                              event Approval(address indexed owner, address indexed spender, uint256 amount);
                          
                              /**
                               * @notice Construct a new Uni token
                               * @param account The initial account to grant all the tokens
                               * @param minter_ The account with minting ability
                               * @param mintingAllowedAfter_ The timestamp after which minting may occur
                               */
                              constructor(address account, address minter_, uint mintingAllowedAfter_) public {
                                  require(mintingAllowedAfter_ >= block.timestamp, "Uni::constructor: minting can only begin after deployment");
                          
                                  balances[account] = uint96(totalSupply);
                                  emit Transfer(address(0), account, totalSupply);
                                  minter = minter_;
                                  emit MinterChanged(address(0), minter);
                                  mintingAllowedAfter = mintingAllowedAfter_;
                              }
                          
                              /**
                               * @notice Change the minter address
                               * @param minter_ The address of the new minter
                               */
                              function setMinter(address minter_) external {
                                  require(msg.sender == minter, "Uni::setMinter: only the minter can change the minter address");
                                  emit MinterChanged(minter, minter_);
                                  minter = minter_;
                              }
                          
                              /**
                               * @notice Mint new tokens
                               * @param dst The address of the destination account
                               * @param rawAmount The number of tokens to be minted
                               */
                              function mint(address dst, uint rawAmount) external {
                                  require(msg.sender == minter, "Uni::mint: only the minter can mint");
                                  require(block.timestamp >= mintingAllowedAfter, "Uni::mint: minting not allowed yet");
                                  require(dst != address(0), "Uni::mint: cannot transfer to the zero address");
                          
                                  // record the mint
                                  mintingAllowedAfter = SafeMath.add(block.timestamp, minimumTimeBetweenMints);
                          
                                  // mint the amount
                                  uint96 amount = safe96(rawAmount, "Uni::mint: amount exceeds 96 bits");
                                  require(amount <= SafeMath.div(SafeMath.mul(totalSupply, mintCap), 100), "Uni::mint: exceeded mint cap");
                                  totalSupply = safe96(SafeMath.add(totalSupply, amount), "Uni::mint: totalSupply exceeds 96 bits");
                          
                                  // transfer the amount to the recipient
                                  balances[dst] = add96(balances[dst], amount, "Uni::mint: transfer amount overflows");
                                  emit Transfer(address(0), dst, amount);
                          
                                  // move delegates
                                  _moveDelegates(address(0), delegates[dst], amount);
                              }
                          
                              /**
                               * @notice Get the number of tokens `spender` is approved to spend on behalf of `account`
                               * @param account The address of the account holding the funds
                               * @param spender The address of the account spending the funds
                               * @return The number of tokens approved
                               */
                              function allowance(address account, address spender) external view returns (uint) {
                                  return allowances[account][spender];
                              }
                          
                              /**
                               * @notice Approve `spender` to transfer up to `amount` from `src`
                               * @dev This will overwrite the approval amount for `spender`
                               *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
                               * @param spender The address of the account which may transfer tokens
                               * @param rawAmount The number of tokens that are approved (2^256-1 means infinite)
                               * @return Whether or not the approval succeeded
                               */
                              function approve(address spender, uint rawAmount) external returns (bool) {
                                  uint96 amount;
                                  if (rawAmount == uint(-1)) {
                                      amount = uint96(-1);
                                  } else {
                                      amount = safe96(rawAmount, "Uni::approve: amount exceeds 96 bits");
                                  }
                          
                                  allowances[msg.sender][spender] = amount;
                          
                                  emit Approval(msg.sender, spender, amount);
                                  return true;
                              }
                          
                              /**
                               * @notice Triggers an approval from owner to spends
                               * @param owner The address to approve from
                               * @param spender The address to be approved
                               * @param rawAmount The number of tokens that are approved (2^256-1 means infinite)
                               * @param deadline The time at which to expire the signature
                               * @param v The recovery byte of the signature
                               * @param r Half of the ECDSA signature pair
                               * @param s Half of the ECDSA signature pair
                               */
                              function permit(address owner, address spender, uint rawAmount, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
                                  uint96 amount;
                                  if (rawAmount == uint(-1)) {
                                      amount = uint96(-1);
                                  } else {
                                      amount = safe96(rawAmount, "Uni::permit: amount exceeds 96 bits");
                                  }
                          
                                  bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainId(), address(this)));
                                  bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, rawAmount, nonces[owner]++, deadline));
                                  bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
                                  address signatory = ecrecover(digest, v, r, s);
                                  require(signatory != address(0), "Uni::permit: invalid signature");
                                  require(signatory == owner, "Uni::permit: unauthorized");
                                  require(now <= deadline, "Uni::permit: signature expired");
                          
                                  allowances[owner][spender] = amount;
                          
                                  emit Approval(owner, spender, amount);
                              }
                          
                              /**
                               * @notice Get the number of tokens held by the `account`
                               * @param account The address of the account to get the balance of
                               * @return The number of tokens held
                               */
                              function balanceOf(address account) external view returns (uint) {
                                  return balances[account];
                              }
                          
                              /**
                               * @notice Transfer `amount` tokens from `msg.sender` to `dst`
                               * @param dst The address of the destination account
                               * @param rawAmount The number of tokens to transfer
                               * @return Whether or not the transfer succeeded
                               */
                              function transfer(address dst, uint rawAmount) external returns (bool) {
                                  uint96 amount = safe96(rawAmount, "Uni::transfer: amount exceeds 96 bits");
                                  _transferTokens(msg.sender, dst, amount);
                                  return true;
                              }
                          
                              /**
                               * @notice Transfer `amount` tokens from `src` to `dst`
                               * @param src The address of the source account
                               * @param dst The address of the destination account
                               * @param rawAmount The number of tokens to transfer
                               * @return Whether or not the transfer succeeded
                               */
                              function transferFrom(address src, address dst, uint rawAmount) external returns (bool) {
                                  address spender = msg.sender;
                                  uint96 spenderAllowance = allowances[src][spender];
                                  uint96 amount = safe96(rawAmount, "Uni::approve: amount exceeds 96 bits");
                          
                                  if (spender != src && spenderAllowance != uint96(-1)) {
                                      uint96 newAllowance = sub96(spenderAllowance, amount, "Uni::transferFrom: transfer amount exceeds spender allowance");
                                      allowances[src][spender] = newAllowance;
                          
                                      emit Approval(src, spender, newAllowance);
                                  }
                          
                                  _transferTokens(src, dst, amount);
                                  return true;
                              }
                          
                              /**
                               * @notice Delegate votes from `msg.sender` to `delegatee`
                               * @param delegatee The address to delegate votes to
                               */
                              function delegate(address delegatee) public {
                                  return _delegate(msg.sender, delegatee);
                              }
                          
                              /**
                               * @notice Delegates votes from signatory to `delegatee`
                               * @param delegatee The address to delegate votes to
                               * @param nonce The contract state required to match the signature
                               * @param expiry The time at which to expire the signature
                               * @param v The recovery byte of the signature
                               * @param r Half of the ECDSA signature pair
                               * @param s Half of the ECDSA signature pair
                               */
                              function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) public {
                                  bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainId(), address(this)));
                                  bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry));
                                  bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
                                  address signatory = ecrecover(digest, v, r, s);
                                  require(signatory != address(0), "Uni::delegateBySig: invalid signature");
                                  require(nonce == nonces[signatory]++, "Uni::delegateBySig: invalid nonce");
                                  require(now <= expiry, "Uni::delegateBySig: signature expired");
                                  return _delegate(signatory, delegatee);
                              }
                          
                              /**
                               * @notice Gets the current votes balance for `account`
                               * @param account The address to get votes balance
                               * @return The number of current votes for `account`
                               */
                              function getCurrentVotes(address account) external view returns (uint96) {
                                  uint32 nCheckpoints = numCheckpoints[account];
                                  return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0;
                              }
                          
                              /**
                               * @notice Determine the prior number of votes for an account as of a block number
                               * @dev Block number must be a finalized block or else this function will revert to prevent misinformation.
                               * @param account The address of the account to check
                               * @param blockNumber The block number to get the vote balance at
                               * @return The number of votes the account had as of the given block
                               */
                              function getPriorVotes(address account, uint blockNumber) public view returns (uint96) {
                                  require(blockNumber < block.number, "Uni::getPriorVotes: not yet determined");
                          
                                  uint32 nCheckpoints = numCheckpoints[account];
                                  if (nCheckpoints == 0) {
                                      return 0;
                                  }
                          
                                  // First check most recent balance
                                  if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) {
                                      return checkpoints[account][nCheckpoints - 1].votes;
                                  }
                          
                                  // Next check implicit zero balance
                                  if (checkpoints[account][0].fromBlock > blockNumber) {
                                      return 0;
                                  }
                          
                                  uint32 lower = 0;
                                  uint32 upper = nCheckpoints - 1;
                                  while (upper > lower) {
                                      uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
                                      Checkpoint memory cp = checkpoints[account][center];
                                      if (cp.fromBlock == blockNumber) {
                                          return cp.votes;
                                      } else if (cp.fromBlock < blockNumber) {
                                          lower = center;
                                      } else {
                                          upper = center - 1;
                                      }
                                  }
                                  return checkpoints[account][lower].votes;
                              }
                          
                              function _delegate(address delegator, address delegatee) internal {
                                  address currentDelegate = delegates[delegator];
                                  uint96 delegatorBalance = balances[delegator];
                                  delegates[delegator] = delegatee;
                          
                                  emit DelegateChanged(delegator, currentDelegate, delegatee);
                          
                                  _moveDelegates(currentDelegate, delegatee, delegatorBalance);
                              }
                          
                              function _transferTokens(address src, address dst, uint96 amount) internal {
                                  require(src != address(0), "Uni::_transferTokens: cannot transfer from the zero address");
                                  require(dst != address(0), "Uni::_transferTokens: cannot transfer to the zero address");
                          
                                  balances[src] = sub96(balances[src], amount, "Uni::_transferTokens: transfer amount exceeds balance");
                                  balances[dst] = add96(balances[dst], amount, "Uni::_transferTokens: transfer amount overflows");
                                  emit Transfer(src, dst, amount);
                          
                                  _moveDelegates(delegates[src], delegates[dst], amount);
                              }
                          
                              function _moveDelegates(address srcRep, address dstRep, uint96 amount) internal {
                                  if (srcRep != dstRep && amount > 0) {
                                      if (srcRep != address(0)) {
                                          uint32 srcRepNum = numCheckpoints[srcRep];
                                          uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0;
                                          uint96 srcRepNew = sub96(srcRepOld, amount, "Uni::_moveVotes: vote amount underflows");
                                          _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew);
                                      }
                          
                                      if (dstRep != address(0)) {
                                          uint32 dstRepNum = numCheckpoints[dstRep];
                                          uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0;
                                          uint96 dstRepNew = add96(dstRepOld, amount, "Uni::_moveVotes: vote amount overflows");
                                          _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew);
                                      }
                                  }
                              }
                          
                              function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint96 oldVotes, uint96 newVotes) internal {
                                uint32 blockNumber = safe32(block.number, "Uni::_writeCheckpoint: block number exceeds 32 bits");
                          
                                if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) {
                                    checkpoints[delegatee][nCheckpoints - 1].votes = newVotes;
                                } else {
                                    checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes);
                                    numCheckpoints[delegatee] = nCheckpoints + 1;
                                }
                          
                                emit DelegateVotesChanged(delegatee, oldVotes, newVotes);
                              }
                          
                              function safe32(uint n, string memory errorMessage) internal pure returns (uint32) {
                                  require(n < 2**32, errorMessage);
                                  return uint32(n);
                              }
                          
                              function safe96(uint n, string memory errorMessage) internal pure returns (uint96) {
                                  require(n < 2**96, errorMessage);
                                  return uint96(n);
                              }
                          
                              function add96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
                                  uint96 c = a + b;
                                  require(c >= a, errorMessage);
                                  return c;
                              }
                          
                              function sub96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) {
                                  require(b <= a, errorMessage);
                                  return a - b;
                              }
                          
                              function getChainId() internal pure returns (uint) {
                                  uint256 chainId;
                                  assembly { chainId := chainid() }
                                  return chainId;
                              }
                          }

                          File 4 of 13: UniswapV3Pool
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity =0.7.6;
                          import './interfaces/IUniswapV3Pool.sol';
                          import './NoDelegateCall.sol';
                          import './libraries/LowGasSafeMath.sol';
                          import './libraries/SafeCast.sol';
                          import './libraries/Tick.sol';
                          import './libraries/TickBitmap.sol';
                          import './libraries/Position.sol';
                          import './libraries/Oracle.sol';
                          import './libraries/FullMath.sol';
                          import './libraries/FixedPoint128.sol';
                          import './libraries/TransferHelper.sol';
                          import './libraries/TickMath.sol';
                          import './libraries/LiquidityMath.sol';
                          import './libraries/SqrtPriceMath.sol';
                          import './libraries/SwapMath.sol';
                          import './interfaces/IUniswapV3PoolDeployer.sol';
                          import './interfaces/IUniswapV3Factory.sol';
                          import './interfaces/IERC20Minimal.sol';
                          import './interfaces/callback/IUniswapV3MintCallback.sol';
                          import './interfaces/callback/IUniswapV3SwapCallback.sol';
                          import './interfaces/callback/IUniswapV3FlashCallback.sol';
                          contract UniswapV3Pool is IUniswapV3Pool, NoDelegateCall {
                              using LowGasSafeMath for uint256;
                              using LowGasSafeMath for int256;
                              using SafeCast for uint256;
                              using SafeCast for int256;
                              using Tick for mapping(int24 => Tick.Info);
                              using TickBitmap for mapping(int16 => uint256);
                              using Position for mapping(bytes32 => Position.Info);
                              using Position for Position.Info;
                              using Oracle for Oracle.Observation[65535];
                              /// @inheritdoc IUniswapV3PoolImmutables
                              address public immutable override factory;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              address public immutable override token0;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              address public immutable override token1;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              uint24 public immutable override fee;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              int24 public immutable override tickSpacing;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              uint128 public immutable override maxLiquidityPerTick;
                              struct Slot0 {
                                  // the current price
                                  uint160 sqrtPriceX96;
                                  // the current tick
                                  int24 tick;
                                  // the most-recently updated index of the observations array
                                  uint16 observationIndex;
                                  // the current maximum number of observations that are being stored
                                  uint16 observationCardinality;
                                  // the next maximum number of observations to store, triggered in observations.write
                                  uint16 observationCardinalityNext;
                                  // the current protocol fee as a percentage of the swap fee taken on withdrawal
                                  // represented as an integer denominator (1/x)%
                                  uint8 feeProtocol;
                                  // whether the pool is locked
                                  bool unlocked;
                              }
                              /// @inheritdoc IUniswapV3PoolState
                              Slot0 public override slot0;
                              /// @inheritdoc IUniswapV3PoolState
                              uint256 public override feeGrowthGlobal0X128;
                              /// @inheritdoc IUniswapV3PoolState
                              uint256 public override feeGrowthGlobal1X128;
                              // accumulated protocol fees in token0/token1 units
                              struct ProtocolFees {
                                  uint128 token0;
                                  uint128 token1;
                              }
                              /// @inheritdoc IUniswapV3PoolState
                              ProtocolFees public override protocolFees;
                              /// @inheritdoc IUniswapV3PoolState
                              uint128 public override liquidity;
                              /// @inheritdoc IUniswapV3PoolState
                              mapping(int24 => Tick.Info) public override ticks;
                              /// @inheritdoc IUniswapV3PoolState
                              mapping(int16 => uint256) public override tickBitmap;
                              /// @inheritdoc IUniswapV3PoolState
                              mapping(bytes32 => Position.Info) public override positions;
                              /// @inheritdoc IUniswapV3PoolState
                              Oracle.Observation[65535] public override observations;
                              /// @dev Mutually exclusive reentrancy protection into the pool to/from a method. This method also prevents entrance
                              /// to a function before the pool is initialized. The reentrancy guard is required throughout the contract because
                              /// we use balance checks to determine the payment status of interactions such as mint, swap and flash.
                              modifier lock() {
                                  require(slot0.unlocked, 'LOK');
                                  slot0.unlocked = false;
                                  _;
                                  slot0.unlocked = true;
                              }
                              /// @dev Prevents calling a function from anyone except the address returned by IUniswapV3Factory#owner()
                              modifier onlyFactoryOwner() {
                                  require(msg.sender == IUniswapV3Factory(factory).owner());
                                  _;
                              }
                              constructor() {
                                  int24 _tickSpacing;
                                  (factory, token0, token1, fee, _tickSpacing) = IUniswapV3PoolDeployer(msg.sender).parameters();
                                  tickSpacing = _tickSpacing;
                                  maxLiquidityPerTick = Tick.tickSpacingToMaxLiquidityPerTick(_tickSpacing);
                              }
                              /// @dev Common checks for valid tick inputs.
                              function checkTicks(int24 tickLower, int24 tickUpper) private pure {
                                  require(tickLower < tickUpper, 'TLU');
                                  require(tickLower >= TickMath.MIN_TICK, 'TLM');
                                  require(tickUpper <= TickMath.MAX_TICK, 'TUM');
                              }
                              /// @dev Returns the block timestamp truncated to 32 bits, i.e. mod 2**32. This method is overridden in tests.
                              function _blockTimestamp() internal view virtual returns (uint32) {
                                  return uint32(block.timestamp); // truncation is desired
                              }
                              /// @dev Get the pool's balance of token0
                              /// @dev This function is gas optimized to avoid a redundant extcodesize check in addition to the returndatasize
                              /// check
                              function balance0() private view returns (uint256) {
                                  (bool success, bytes memory data) =
                                      token0.staticcall(abi.encodeWithSelector(IERC20Minimal.balanceOf.selector, address(this)));
                                  require(success && data.length >= 32);
                                  return abi.decode(data, (uint256));
                              }
                              /// @dev Get the pool's balance of token1
                              /// @dev This function is gas optimized to avoid a redundant extcodesize check in addition to the returndatasize
                              /// check
                              function balance1() private view returns (uint256) {
                                  (bool success, bytes memory data) =
                                      token1.staticcall(abi.encodeWithSelector(IERC20Minimal.balanceOf.selector, address(this)));
                                  require(success && data.length >= 32);
                                  return abi.decode(data, (uint256));
                              }
                              /// @inheritdoc IUniswapV3PoolDerivedState
                              function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
                                  external
                                  view
                                  override
                                  noDelegateCall
                                  returns (
                                      int56 tickCumulativeInside,
                                      uint160 secondsPerLiquidityInsideX128,
                                      uint32 secondsInside
                                  )
                              {
                                  checkTicks(tickLower, tickUpper);
                                  int56 tickCumulativeLower;
                                  int56 tickCumulativeUpper;
                                  uint160 secondsPerLiquidityOutsideLowerX128;
                                  uint160 secondsPerLiquidityOutsideUpperX128;
                                  uint32 secondsOutsideLower;
                                  uint32 secondsOutsideUpper;
                                  {
                                      Tick.Info storage lower = ticks[tickLower];
                                      Tick.Info storage upper = ticks[tickUpper];
                                      bool initializedLower;
                                      (tickCumulativeLower, secondsPerLiquidityOutsideLowerX128, secondsOutsideLower, initializedLower) = (
                                          lower.tickCumulativeOutside,
                                          lower.secondsPerLiquidityOutsideX128,
                                          lower.secondsOutside,
                                          lower.initialized
                                      );
                                      require(initializedLower);
                                      bool initializedUpper;
                                      (tickCumulativeUpper, secondsPerLiquidityOutsideUpperX128, secondsOutsideUpper, initializedUpper) = (
                                          upper.tickCumulativeOutside,
                                          upper.secondsPerLiquidityOutsideX128,
                                          upper.secondsOutside,
                                          upper.initialized
                                      );
                                      require(initializedUpper);
                                  }
                                  Slot0 memory _slot0 = slot0;
                                  if (_slot0.tick < tickLower) {
                                      return (
                                          tickCumulativeLower - tickCumulativeUpper,
                                          secondsPerLiquidityOutsideLowerX128 - secondsPerLiquidityOutsideUpperX128,
                                          secondsOutsideLower - secondsOutsideUpper
                                      );
                                  } else if (_slot0.tick < tickUpper) {
                                      uint32 time = _blockTimestamp();
                                      (int56 tickCumulative, uint160 secondsPerLiquidityCumulativeX128) =
                                          observations.observeSingle(
                                              time,
                                              0,
                                              _slot0.tick,
                                              _slot0.observationIndex,
                                              liquidity,
                                              _slot0.observationCardinality
                                          );
                                      return (
                                          tickCumulative - tickCumulativeLower - tickCumulativeUpper,
                                          secondsPerLiquidityCumulativeX128 -
                                              secondsPerLiquidityOutsideLowerX128 -
                                              secondsPerLiquidityOutsideUpperX128,
                                          time - secondsOutsideLower - secondsOutsideUpper
                                      );
                                  } else {
                                      return (
                                          tickCumulativeUpper - tickCumulativeLower,
                                          secondsPerLiquidityOutsideUpperX128 - secondsPerLiquidityOutsideLowerX128,
                                          secondsOutsideUpper - secondsOutsideLower
                                      );
                                  }
                              }
                              /// @inheritdoc IUniswapV3PoolDerivedState
                              function observe(uint32[] calldata secondsAgos)
                                  external
                                  view
                                  override
                                  noDelegateCall
                                  returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s)
                              {
                                  return
                                      observations.observe(
                                          _blockTimestamp(),
                                          secondsAgos,
                                          slot0.tick,
                                          slot0.observationIndex,
                                          liquidity,
                                          slot0.observationCardinality
                                      );
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function increaseObservationCardinalityNext(uint16 observationCardinalityNext)
                                  external
                                  override
                                  lock
                                  noDelegateCall
                              {
                                  uint16 observationCardinalityNextOld = slot0.observationCardinalityNext; // for the event
                                  uint16 observationCardinalityNextNew =
                                      observations.grow(observationCardinalityNextOld, observationCardinalityNext);
                                  slot0.observationCardinalityNext = observationCardinalityNextNew;
                                  if (observationCardinalityNextOld != observationCardinalityNextNew)
                                      emit IncreaseObservationCardinalityNext(observationCardinalityNextOld, observationCardinalityNextNew);
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              /// @dev not locked because it initializes unlocked
                              function initialize(uint160 sqrtPriceX96) external override {
                                  require(slot0.sqrtPriceX96 == 0, 'AI');
                                  int24 tick = TickMath.getTickAtSqrtRatio(sqrtPriceX96);
                                  (uint16 cardinality, uint16 cardinalityNext) = observations.initialize(_blockTimestamp());
                                  slot0 = Slot0({
                                      sqrtPriceX96: sqrtPriceX96,
                                      tick: tick,
                                      observationIndex: 0,
                                      observationCardinality: cardinality,
                                      observationCardinalityNext: cardinalityNext,
                                      feeProtocol: 0,
                                      unlocked: true
                                  });
                                  emit Initialize(sqrtPriceX96, tick);
                              }
                              struct ModifyPositionParams {
                                  // the address that owns the position
                                  address owner;
                                  // the lower and upper tick of the position
                                  int24 tickLower;
                                  int24 tickUpper;
                                  // any change in liquidity
                                  int128 liquidityDelta;
                              }
                              /// @dev Effect some changes to a position
                              /// @param params the position details and the change to the position's liquidity to effect
                              /// @return position a storage pointer referencing the position with the given owner and tick range
                              /// @return amount0 the amount of token0 owed to the pool, negative if the pool should pay the recipient
                              /// @return amount1 the amount of token1 owed to the pool, negative if the pool should pay the recipient
                              function _modifyPosition(ModifyPositionParams memory params)
                                  private
                                  noDelegateCall
                                  returns (
                                      Position.Info storage position,
                                      int256 amount0,
                                      int256 amount1
                                  )
                              {
                                  checkTicks(params.tickLower, params.tickUpper);
                                  Slot0 memory _slot0 = slot0; // SLOAD for gas optimization
                                  position = _updatePosition(
                                      params.owner,
                                      params.tickLower,
                                      params.tickUpper,
                                      params.liquidityDelta,
                                      _slot0.tick
                                  );
                                  if (params.liquidityDelta != 0) {
                                      if (_slot0.tick < params.tickLower) {
                                          // current tick is below the passed range; liquidity can only become in range by crossing from left to
                                          // right, when we'll need _more_ token0 (it's becoming more valuable) so user must provide it
                                          amount0 = SqrtPriceMath.getAmount0Delta(
                                              TickMath.getSqrtRatioAtTick(params.tickLower),
                                              TickMath.getSqrtRatioAtTick(params.tickUpper),
                                              params.liquidityDelta
                                          );
                                      } else if (_slot0.tick < params.tickUpper) {
                                          // current tick is inside the passed range
                                          uint128 liquidityBefore = liquidity; // SLOAD for gas optimization
                                          // write an oracle entry
                                          (slot0.observationIndex, slot0.observationCardinality) = observations.write(
                                              _slot0.observationIndex,
                                              _blockTimestamp(),
                                              _slot0.tick,
                                              liquidityBefore,
                                              _slot0.observationCardinality,
                                              _slot0.observationCardinalityNext
                                          );
                                          amount0 = SqrtPriceMath.getAmount0Delta(
                                              _slot0.sqrtPriceX96,
                                              TickMath.getSqrtRatioAtTick(params.tickUpper),
                                              params.liquidityDelta
                                          );
                                          amount1 = SqrtPriceMath.getAmount1Delta(
                                              TickMath.getSqrtRatioAtTick(params.tickLower),
                                              _slot0.sqrtPriceX96,
                                              params.liquidityDelta
                                          );
                                          liquidity = LiquidityMath.addDelta(liquidityBefore, params.liquidityDelta);
                                      } else {
                                          // current tick is above the passed range; liquidity can only become in range by crossing from right to
                                          // left, when we'll need _more_ token1 (it's becoming more valuable) so user must provide it
                                          amount1 = SqrtPriceMath.getAmount1Delta(
                                              TickMath.getSqrtRatioAtTick(params.tickLower),
                                              TickMath.getSqrtRatioAtTick(params.tickUpper),
                                              params.liquidityDelta
                                          );
                                      }
                                  }
                              }
                              /// @dev Gets and updates a position with the given liquidity delta
                              /// @param owner the owner of the position
                              /// @param tickLower the lower tick of the position's tick range
                              /// @param tickUpper the upper tick of the position's tick range
                              /// @param tick the current tick, passed to avoid sloads
                              function _updatePosition(
                                  address owner,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  int128 liquidityDelta,
                                  int24 tick
                              ) private returns (Position.Info storage position) {
                                  position = positions.get(owner, tickLower, tickUpper);
                                  uint256 _feeGrowthGlobal0X128 = feeGrowthGlobal0X128; // SLOAD for gas optimization
                                  uint256 _feeGrowthGlobal1X128 = feeGrowthGlobal1X128; // SLOAD for gas optimization
                                  // if we need to update the ticks, do it
                                  bool flippedLower;
                                  bool flippedUpper;
                                  if (liquidityDelta != 0) {
                                      uint32 time = _blockTimestamp();
                                      (int56 tickCumulative, uint160 secondsPerLiquidityCumulativeX128) =
                                          observations.observeSingle(
                                              time,
                                              0,
                                              slot0.tick,
                                              slot0.observationIndex,
                                              liquidity,
                                              slot0.observationCardinality
                                          );
                                      flippedLower = ticks.update(
                                          tickLower,
                                          tick,
                                          liquidityDelta,
                                          _feeGrowthGlobal0X128,
                                          _feeGrowthGlobal1X128,
                                          secondsPerLiquidityCumulativeX128,
                                          tickCumulative,
                                          time,
                                          false,
                                          maxLiquidityPerTick
                                      );
                                      flippedUpper = ticks.update(
                                          tickUpper,
                                          tick,
                                          liquidityDelta,
                                          _feeGrowthGlobal0X128,
                                          _feeGrowthGlobal1X128,
                                          secondsPerLiquidityCumulativeX128,
                                          tickCumulative,
                                          time,
                                          true,
                                          maxLiquidityPerTick
                                      );
                                      if (flippedLower) {
                                          tickBitmap.flipTick(tickLower, tickSpacing);
                                      }
                                      if (flippedUpper) {
                                          tickBitmap.flipTick(tickUpper, tickSpacing);
                                      }
                                  }
                                  (uint256 feeGrowthInside0X128, uint256 feeGrowthInside1X128) =
                                      ticks.getFeeGrowthInside(tickLower, tickUpper, tick, _feeGrowthGlobal0X128, _feeGrowthGlobal1X128);
                                  position.update(liquidityDelta, feeGrowthInside0X128, feeGrowthInside1X128);
                                  // clear any tick data that is no longer needed
                                  if (liquidityDelta < 0) {
                                      if (flippedLower) {
                                          ticks.clear(tickLower);
                                      }
                                      if (flippedUpper) {
                                          ticks.clear(tickUpper);
                                      }
                                  }
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              /// @dev noDelegateCall is applied indirectly via _modifyPosition
                              function mint(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount,
                                  bytes calldata data
                              ) external override lock returns (uint256 amount0, uint256 amount1) {
                                  require(amount > 0);
                                  (, int256 amount0Int, int256 amount1Int) =
                                      _modifyPosition(
                                          ModifyPositionParams({
                                              owner: recipient,
                                              tickLower: tickLower,
                                              tickUpper: tickUpper,
                                              liquidityDelta: int256(amount).toInt128()
                                          })
                                      );
                                  amount0 = uint256(amount0Int);
                                  amount1 = uint256(amount1Int);
                                  uint256 balance0Before;
                                  uint256 balance1Before;
                                  if (amount0 > 0) balance0Before = balance0();
                                  if (amount1 > 0) balance1Before = balance1();
                                  IUniswapV3MintCallback(msg.sender).uniswapV3MintCallback(amount0, amount1, data);
                                  if (amount0 > 0) require(balance0Before.add(amount0) <= balance0(), 'M0');
                                  if (amount1 > 0) require(balance1Before.add(amount1) <= balance1(), 'M1');
                                  emit Mint(msg.sender, recipient, tickLower, tickUpper, amount, amount0, amount1);
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function collect(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external override lock returns (uint128 amount0, uint128 amount1) {
                                  // we don't need to checkTicks here, because invalid positions will never have non-zero tokensOwed{0,1}
                                  Position.Info storage position = positions.get(msg.sender, tickLower, tickUpper);
                                  amount0 = amount0Requested > position.tokensOwed0 ? position.tokensOwed0 : amount0Requested;
                                  amount1 = amount1Requested > position.tokensOwed1 ? position.tokensOwed1 : amount1Requested;
                                  if (amount0 > 0) {
                                      position.tokensOwed0 -= amount0;
                                      TransferHelper.safeTransfer(token0, recipient, amount0);
                                  }
                                  if (amount1 > 0) {
                                      position.tokensOwed1 -= amount1;
                                      TransferHelper.safeTransfer(token1, recipient, amount1);
                                  }
                                  emit Collect(msg.sender, recipient, tickLower, tickUpper, amount0, amount1);
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              /// @dev noDelegateCall is applied indirectly via _modifyPosition
                              function burn(
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount
                              ) external override lock returns (uint256 amount0, uint256 amount1) {
                                  (Position.Info storage position, int256 amount0Int, int256 amount1Int) =
                                      _modifyPosition(
                                          ModifyPositionParams({
                                              owner: msg.sender,
                                              tickLower: tickLower,
                                              tickUpper: tickUpper,
                                              liquidityDelta: -int256(amount).toInt128()
                                          })
                                      );
                                  amount0 = uint256(-amount0Int);
                                  amount1 = uint256(-amount1Int);
                                  if (amount0 > 0 || amount1 > 0) {
                                      (position.tokensOwed0, position.tokensOwed1) = (
                                          position.tokensOwed0 + uint128(amount0),
                                          position.tokensOwed1 + uint128(amount1)
                                      );
                                  }
                                  emit Burn(msg.sender, tickLower, tickUpper, amount, amount0, amount1);
                              }
                              struct SwapCache {
                                  // the protocol fee for the input token
                                  uint8 feeProtocol;
                                  // liquidity at the beginning of the swap
                                  uint128 liquidityStart;
                                  // the timestamp of the current block
                                  uint32 blockTimestamp;
                                  // the current value of the tick accumulator, computed only if we cross an initialized tick
                                  int56 tickCumulative;
                                  // the current value of seconds per liquidity accumulator, computed only if we cross an initialized tick
                                  uint160 secondsPerLiquidityCumulativeX128;
                                  // whether we've computed and cached the above two accumulators
                                  bool computedLatestObservation;
                              }
                              // the top level state of the swap, the results of which are recorded in storage at the end
                              struct SwapState {
                                  // the amount remaining to be swapped in/out of the input/output asset
                                  int256 amountSpecifiedRemaining;
                                  // the amount already swapped out/in of the output/input asset
                                  int256 amountCalculated;
                                  // current sqrt(price)
                                  uint160 sqrtPriceX96;
                                  // the tick associated with the current price
                                  int24 tick;
                                  // the global fee growth of the input token
                                  uint256 feeGrowthGlobalX128;
                                  // amount of input token paid as protocol fee
                                  uint128 protocolFee;
                                  // the current liquidity in range
                                  uint128 liquidity;
                              }
                              struct StepComputations {
                                  // the price at the beginning of the step
                                  uint160 sqrtPriceStartX96;
                                  // the next tick to swap to from the current tick in the swap direction
                                  int24 tickNext;
                                  // whether tickNext is initialized or not
                                  bool initialized;
                                  // sqrt(price) for the next tick (1/0)
                                  uint160 sqrtPriceNextX96;
                                  // how much is being swapped in in this step
                                  uint256 amountIn;
                                  // how much is being swapped out
                                  uint256 amountOut;
                                  // how much fee is being paid in
                                  uint256 feeAmount;
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function swap(
                                  address recipient,
                                  bool zeroForOne,
                                  int256 amountSpecified,
                                  uint160 sqrtPriceLimitX96,
                                  bytes calldata data
                              ) external override noDelegateCall returns (int256 amount0, int256 amount1) {
                                  require(amountSpecified != 0, 'AS');
                                  Slot0 memory slot0Start = slot0;
                                  require(slot0Start.unlocked, 'LOK');
                                  require(
                                      zeroForOne
                                          ? sqrtPriceLimitX96 < slot0Start.sqrtPriceX96 && sqrtPriceLimitX96 > TickMath.MIN_SQRT_RATIO
                                          : sqrtPriceLimitX96 > slot0Start.sqrtPriceX96 && sqrtPriceLimitX96 < TickMath.MAX_SQRT_RATIO,
                                      'SPL'
                                  );
                                  slot0.unlocked = false;
                                  SwapCache memory cache =
                                      SwapCache({
                                          liquidityStart: liquidity,
                                          blockTimestamp: _blockTimestamp(),
                                          feeProtocol: zeroForOne ? (slot0Start.feeProtocol % 16) : (slot0Start.feeProtocol >> 4),
                                          secondsPerLiquidityCumulativeX128: 0,
                                          tickCumulative: 0,
                                          computedLatestObservation: false
                                      });
                                  bool exactInput = amountSpecified > 0;
                                  SwapState memory state =
                                      SwapState({
                                          amountSpecifiedRemaining: amountSpecified,
                                          amountCalculated: 0,
                                          sqrtPriceX96: slot0Start.sqrtPriceX96,
                                          tick: slot0Start.tick,
                                          feeGrowthGlobalX128: zeroForOne ? feeGrowthGlobal0X128 : feeGrowthGlobal1X128,
                                          protocolFee: 0,
                                          liquidity: cache.liquidityStart
                                      });
                                  // continue swapping as long as we haven't used the entire input/output and haven't reached the price limit
                                  while (state.amountSpecifiedRemaining != 0 && state.sqrtPriceX96 != sqrtPriceLimitX96) {
                                      StepComputations memory step;
                                      step.sqrtPriceStartX96 = state.sqrtPriceX96;
                                      (step.tickNext, step.initialized) = tickBitmap.nextInitializedTickWithinOneWord(
                                          state.tick,
                                          tickSpacing,
                                          zeroForOne
                                      );
                                      // ensure that we do not overshoot the min/max tick, as the tick bitmap is not aware of these bounds
                                      if (step.tickNext < TickMath.MIN_TICK) {
                                          step.tickNext = TickMath.MIN_TICK;
                                      } else if (step.tickNext > TickMath.MAX_TICK) {
                                          step.tickNext = TickMath.MAX_TICK;
                                      }
                                      // get the price for the next tick
                                      step.sqrtPriceNextX96 = TickMath.getSqrtRatioAtTick(step.tickNext);
                                      // compute values to swap to the target tick, price limit, or point where input/output amount is exhausted
                                      (state.sqrtPriceX96, step.amountIn, step.amountOut, step.feeAmount) = SwapMath.computeSwapStep(
                                          state.sqrtPriceX96,
                                          (zeroForOne ? step.sqrtPriceNextX96 < sqrtPriceLimitX96 : step.sqrtPriceNextX96 > sqrtPriceLimitX96)
                                              ? sqrtPriceLimitX96
                                              : step.sqrtPriceNextX96,
                                          state.liquidity,
                                          state.amountSpecifiedRemaining,
                                          fee
                                      );
                                      if (exactInput) {
                                          state.amountSpecifiedRemaining -= (step.amountIn + step.feeAmount).toInt256();
                                          state.amountCalculated = state.amountCalculated.sub(step.amountOut.toInt256());
                                      } else {
                                          state.amountSpecifiedRemaining += step.amountOut.toInt256();
                                          state.amountCalculated = state.amountCalculated.add((step.amountIn + step.feeAmount).toInt256());
                                      }
                                      // if the protocol fee is on, calculate how much is owed, decrement feeAmount, and increment protocolFee
                                      if (cache.feeProtocol > 0) {
                                          uint256 delta = step.feeAmount / cache.feeProtocol;
                                          step.feeAmount -= delta;
                                          state.protocolFee += uint128(delta);
                                      }
                                      // update global fee tracker
                                      if (state.liquidity > 0)
                                          state.feeGrowthGlobalX128 += FullMath.mulDiv(step.feeAmount, FixedPoint128.Q128, state.liquidity);
                                      // shift tick if we reached the next price
                                      if (state.sqrtPriceX96 == step.sqrtPriceNextX96) {
                                          // if the tick is initialized, run the tick transition
                                          if (step.initialized) {
                                              // check for the placeholder value, which we replace with the actual value the first time the swap
                                              // crosses an initialized tick
                                              if (!cache.computedLatestObservation) {
                                                  (cache.tickCumulative, cache.secondsPerLiquidityCumulativeX128) = observations.observeSingle(
                                                      cache.blockTimestamp,
                                                      0,
                                                      slot0Start.tick,
                                                      slot0Start.observationIndex,
                                                      cache.liquidityStart,
                                                      slot0Start.observationCardinality
                                                  );
                                                  cache.computedLatestObservation = true;
                                              }
                                              int128 liquidityNet =
                                                  ticks.cross(
                                                      step.tickNext,
                                                      (zeroForOne ? state.feeGrowthGlobalX128 : feeGrowthGlobal0X128),
                                                      (zeroForOne ? feeGrowthGlobal1X128 : state.feeGrowthGlobalX128),
                                                      cache.secondsPerLiquidityCumulativeX128,
                                                      cache.tickCumulative,
                                                      cache.blockTimestamp
                                                  );
                                              // if we're moving leftward, we interpret liquidityNet as the opposite sign
                                              // safe because liquidityNet cannot be type(int128).min
                                              if (zeroForOne) liquidityNet = -liquidityNet;
                                              state.liquidity = LiquidityMath.addDelta(state.liquidity, liquidityNet);
                                          }
                                          state.tick = zeroForOne ? step.tickNext - 1 : step.tickNext;
                                      } else if (state.sqrtPriceX96 != step.sqrtPriceStartX96) {
                                          // recompute unless we're on a lower tick boundary (i.e. already transitioned ticks), and haven't moved
                                          state.tick = TickMath.getTickAtSqrtRatio(state.sqrtPriceX96);
                                      }
                                  }
                                  // update tick and write an oracle entry if the tick change
                                  if (state.tick != slot0Start.tick) {
                                      (uint16 observationIndex, uint16 observationCardinality) =
                                          observations.write(
                                              slot0Start.observationIndex,
                                              cache.blockTimestamp,
                                              slot0Start.tick,
                                              cache.liquidityStart,
                                              slot0Start.observationCardinality,
                                              slot0Start.observationCardinalityNext
                                          );
                                      (slot0.sqrtPriceX96, slot0.tick, slot0.observationIndex, slot0.observationCardinality) = (
                                          state.sqrtPriceX96,
                                          state.tick,
                                          observationIndex,
                                          observationCardinality
                                      );
                                  } else {
                                      // otherwise just update the price
                                      slot0.sqrtPriceX96 = state.sqrtPriceX96;
                                  }
                                  // update liquidity if it changed
                                  if (cache.liquidityStart != state.liquidity) liquidity = state.liquidity;
                                  // update fee growth global and, if necessary, protocol fees
                                  // overflow is acceptable, protocol has to withdraw before it hits type(uint128).max fees
                                  if (zeroForOne) {
                                      feeGrowthGlobal0X128 = state.feeGrowthGlobalX128;
                                      if (state.protocolFee > 0) protocolFees.token0 += state.protocolFee;
                                  } else {
                                      feeGrowthGlobal1X128 = state.feeGrowthGlobalX128;
                                      if (state.protocolFee > 0) protocolFees.token1 += state.protocolFee;
                                  }
                                  (amount0, amount1) = zeroForOne == exactInput
                                      ? (amountSpecified - state.amountSpecifiedRemaining, state.amountCalculated)
                                      : (state.amountCalculated, amountSpecified - state.amountSpecifiedRemaining);
                                  // do the transfers and collect payment
                                  if (zeroForOne) {
                                      if (amount1 < 0) TransferHelper.safeTransfer(token1, recipient, uint256(-amount1));
                                      uint256 balance0Before = balance0();
                                      IUniswapV3SwapCallback(msg.sender).uniswapV3SwapCallback(amount0, amount1, data);
                                      require(balance0Before.add(uint256(amount0)) <= balance0(), 'IIA');
                                  } else {
                                      if (amount0 < 0) TransferHelper.safeTransfer(token0, recipient, uint256(-amount0));
                                      uint256 balance1Before = balance1();
                                      IUniswapV3SwapCallback(msg.sender).uniswapV3SwapCallback(amount0, amount1, data);
                                      require(balance1Before.add(uint256(amount1)) <= balance1(), 'IIA');
                                  }
                                  emit Swap(msg.sender, recipient, amount0, amount1, state.sqrtPriceX96, state.liquidity, state.tick);
                                  slot0.unlocked = true;
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function flash(
                                  address recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  bytes calldata data
                              ) external override lock noDelegateCall {
                                  uint128 _liquidity = liquidity;
                                  require(_liquidity > 0, 'L');
                                  uint256 fee0 = FullMath.mulDivRoundingUp(amount0, fee, 1e6);
                                  uint256 fee1 = FullMath.mulDivRoundingUp(amount1, fee, 1e6);
                                  uint256 balance0Before = balance0();
                                  uint256 balance1Before = balance1();
                                  if (amount0 > 0) TransferHelper.safeTransfer(token0, recipient, amount0);
                                  if (amount1 > 0) TransferHelper.safeTransfer(token1, recipient, amount1);
                                  IUniswapV3FlashCallback(msg.sender).uniswapV3FlashCallback(fee0, fee1, data);
                                  uint256 balance0After = balance0();
                                  uint256 balance1After = balance1();
                                  require(balance0Before.add(fee0) <= balance0After, 'F0');
                                  require(balance1Before.add(fee1) <= balance1After, 'F1');
                                  // sub is safe because we know balanceAfter is gt balanceBefore by at least fee
                                  uint256 paid0 = balance0After - balance0Before;
                                  uint256 paid1 = balance1After - balance1Before;
                                  if (paid0 > 0) {
                                      uint8 feeProtocol0 = slot0.feeProtocol % 16;
                                      uint256 fees0 = feeProtocol0 == 0 ? 0 : paid0 / feeProtocol0;
                                      if (uint128(fees0) > 0) protocolFees.token0 += uint128(fees0);
                                      feeGrowthGlobal0X128 += FullMath.mulDiv(paid0 - fees0, FixedPoint128.Q128, _liquidity);
                                  }
                                  if (paid1 > 0) {
                                      uint8 feeProtocol1 = slot0.feeProtocol >> 4;
                                      uint256 fees1 = feeProtocol1 == 0 ? 0 : paid1 / feeProtocol1;
                                      if (uint128(fees1) > 0) protocolFees.token1 += uint128(fees1);
                                      feeGrowthGlobal1X128 += FullMath.mulDiv(paid1 - fees1, FixedPoint128.Q128, _liquidity);
                                  }
                                  emit Flash(msg.sender, recipient, amount0, amount1, paid0, paid1);
                              }
                              /// @inheritdoc IUniswapV3PoolOwnerActions
                              function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external override lock onlyFactoryOwner {
                                  require(
                                      (feeProtocol0 == 0 || (feeProtocol0 >= 4 && feeProtocol0 <= 10)) &&
                                          (feeProtocol1 == 0 || (feeProtocol1 >= 4 && feeProtocol1 <= 10))
                                  );
                                  uint8 feeProtocolOld = slot0.feeProtocol;
                                  slot0.feeProtocol = feeProtocol0 + (feeProtocol1 << 4);
                                  emit SetFeeProtocol(feeProtocolOld % 16, feeProtocolOld >> 4, feeProtocol0, feeProtocol1);
                              }
                              /// @inheritdoc IUniswapV3PoolOwnerActions
                              function collectProtocol(
                                  address recipient,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external override lock onlyFactoryOwner returns (uint128 amount0, uint128 amount1) {
                                  amount0 = amount0Requested > protocolFees.token0 ? protocolFees.token0 : amount0Requested;
                                  amount1 = amount1Requested > protocolFees.token1 ? protocolFees.token1 : amount1Requested;
                                  if (amount0 > 0) {
                                      if (amount0 == protocolFees.token0) amount0--; // ensure that the slot is not cleared, for gas savings
                                      protocolFees.token0 -= amount0;
                                      TransferHelper.safeTransfer(token0, recipient, amount0);
                                  }
                                  if (amount1 > 0) {
                                      if (amount1 == protocolFees.token1) amount1--; // ensure that the slot is not cleared, for gas savings
                                      protocolFees.token1 -= amount1;
                                      TransferHelper.safeTransfer(token1, recipient, amount1);
                                  }
                                  emit CollectProtocol(msg.sender, recipient, amount0, amount1);
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          import './pool/IUniswapV3PoolImmutables.sol';
                          import './pool/IUniswapV3PoolState.sol';
                          import './pool/IUniswapV3PoolDerivedState.sol';
                          import './pool/IUniswapV3PoolActions.sol';
                          import './pool/IUniswapV3PoolOwnerActions.sol';
                          import './pool/IUniswapV3PoolEvents.sol';
                          /// @title The interface for a Uniswap V3 Pool
                          /// @notice A Uniswap pool facilitates swapping and automated market making between any two assets that strictly conform
                          /// to the ERC20 specification
                          /// @dev The pool interface is broken up into many smaller pieces
                          interface IUniswapV3Pool is
                              IUniswapV3PoolImmutables,
                              IUniswapV3PoolState,
                              IUniswapV3PoolDerivedState,
                              IUniswapV3PoolActions,
                              IUniswapV3PoolOwnerActions,
                              IUniswapV3PoolEvents
                          {
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity =0.7.6;
                          /// @title Prevents delegatecall to a contract
                          /// @notice Base contract that provides a modifier for preventing delegatecall to methods in a child contract
                          abstract contract NoDelegateCall {
                              /// @dev The original address of this contract
                              address private immutable original;
                              constructor() {
                                  // Immutables are computed in the init code of the contract, and then inlined into the deployed bytecode.
                                  // In other words, this variable won't change when it's checked at runtime.
                                  original = address(this);
                              }
                              /// @dev Private method is used instead of inlining into modifier because modifiers are copied into each method,
                              ///     and the use of immutable means the address bytes are copied in every place the modifier is used.
                              function checkNotDelegateCall() private view {
                                  require(address(this) == original);
                              }
                              /// @notice Prevents delegatecall into the modified method
                              modifier noDelegateCall() {
                                  checkNotDelegateCall();
                                  _;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.0;
                          /// @title Optimized overflow and underflow safe math operations
                          /// @notice Contains methods for doing math operations that revert on overflow or underflow for minimal gas cost
                          library LowGasSafeMath {
                              /// @notice Returns x + y, reverts if sum overflows uint256
                              /// @param x The augend
                              /// @param y The addend
                              /// @return z The sum of x and y
                              function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require((z = x + y) >= x);
                              }
                              /// @notice Returns x - y, reverts if underflows
                              /// @param x The minuend
                              /// @param y The subtrahend
                              /// @return z The difference of x and y
                              function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require((z = x - y) <= x);
                              }
                              /// @notice Returns x * y, reverts if overflows
                              /// @param x The multiplicand
                              /// @param y The multiplier
                              /// @return z The product of x and y
                              function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require(x == 0 || (z = x * y) / x == y);
                              }
                              /// @notice Returns x + y, reverts if overflows or underflows
                              /// @param x The augend
                              /// @param y The addend
                              /// @return z The sum of x and y
                              function add(int256 x, int256 y) internal pure returns (int256 z) {
                                  require((z = x + y) >= x == (y >= 0));
                              }
                              /// @notice Returns x - y, reverts if overflows or underflows
                              /// @param x The minuend
                              /// @param y The subtrahend
                              /// @return z The difference of x and y
                              function sub(int256 x, int256 y) internal pure returns (int256 z) {
                                  require((z = x - y) <= x == (y >= 0));
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Safe casting methods
                          /// @notice Contains methods for safely casting between types
                          library SafeCast {
                              /// @notice Cast a uint256 to a uint160, revert on overflow
                              /// @param y The uint256 to be downcasted
                              /// @return z The downcasted integer, now type uint160
                              function toUint160(uint256 y) internal pure returns (uint160 z) {
                                  require((z = uint160(y)) == y);
                              }
                              /// @notice Cast a int256 to a int128, revert on overflow or underflow
                              /// @param y The int256 to be downcasted
                              /// @return z The downcasted integer, now type int128
                              function toInt128(int256 y) internal pure returns (int128 z) {
                                  require((z = int128(y)) == y);
                              }
                              /// @notice Cast a uint256 to a int256, revert on overflow
                              /// @param y The uint256 to be casted
                              /// @return z The casted integer, now type int256
                              function toInt256(uint256 y) internal pure returns (int256 z) {
                                  require(y < 2**255);
                                  z = int256(y);
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './LowGasSafeMath.sol';
                          import './SafeCast.sol';
                          import './TickMath.sol';
                          import './LiquidityMath.sol';
                          /// @title Tick
                          /// @notice Contains functions for managing tick processes and relevant calculations
                          library Tick {
                              using LowGasSafeMath for int256;
                              using SafeCast for int256;
                              // info stored for each initialized individual tick
                              struct Info {
                                  // the total position liquidity that references this tick
                                  uint128 liquidityGross;
                                  // amount of net liquidity added (subtracted) when tick is crossed from left to right (right to left),
                                  int128 liquidityNet;
                                  // fee growth per unit of liquidity on the _other_ side of this tick (relative to the current tick)
                                  // only has relative meaning, not absolute — the value depends on when the tick is initialized
                                  uint256 feeGrowthOutside0X128;
                                  uint256 feeGrowthOutside1X128;
                                  // the cumulative tick value on the other side of the tick
                                  int56 tickCumulativeOutside;
                                  // the seconds per unit of liquidity on the _other_ side of this tick (relative to the current tick)
                                  // only has relative meaning, not absolute — the value depends on when the tick is initialized
                                  uint160 secondsPerLiquidityOutsideX128;
                                  // the seconds spent on the other side of the tick (relative to the current tick)
                                  // only has relative meaning, not absolute — the value depends on when the tick is initialized
                                  uint32 secondsOutside;
                                  // true iff the tick is initialized, i.e. the value is exactly equivalent to the expression liquidityGross != 0
                                  // these 8 bits are set to prevent fresh sstores when crossing newly initialized ticks
                                  bool initialized;
                              }
                              /// @notice Derives max liquidity per tick from given tick spacing
                              /// @dev Executed within the pool constructor
                              /// @param tickSpacing The amount of required tick separation, realized in multiples of `tickSpacing`
                              ///     e.g., a tickSpacing of 3 requires ticks to be initialized every 3rd tick i.e., ..., -6, -3, 0, 3, 6, ...
                              /// @return The max liquidity per tick
                              function tickSpacingToMaxLiquidityPerTick(int24 tickSpacing) internal pure returns (uint128) {
                                  int24 minTick = (TickMath.MIN_TICK / tickSpacing) * tickSpacing;
                                  int24 maxTick = (TickMath.MAX_TICK / tickSpacing) * tickSpacing;
                                  uint24 numTicks = uint24((maxTick - minTick) / tickSpacing) + 1;
                                  return type(uint128).max / numTicks;
                              }
                              /// @notice Retrieves fee growth data
                              /// @param self The mapping containing all tick information for initialized ticks
                              /// @param tickLower The lower tick boundary of the position
                              /// @param tickUpper The upper tick boundary of the position
                              /// @param tickCurrent The current tick
                              /// @param feeGrowthGlobal0X128 The all-time global fee growth, per unit of liquidity, in token0
                              /// @param feeGrowthGlobal1X128 The all-time global fee growth, per unit of liquidity, in token1
                              /// @return feeGrowthInside0X128 The all-time fee growth in token0, per unit of liquidity, inside the position's tick boundaries
                              /// @return feeGrowthInside1X128 The all-time fee growth in token1, per unit of liquidity, inside the position's tick boundaries
                              function getFeeGrowthInside(
                                  mapping(int24 => Tick.Info) storage self,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  int24 tickCurrent,
                                  uint256 feeGrowthGlobal0X128,
                                  uint256 feeGrowthGlobal1X128
                              ) internal view returns (uint256 feeGrowthInside0X128, uint256 feeGrowthInside1X128) {
                                  Info storage lower = self[tickLower];
                                  Info storage upper = self[tickUpper];
                                  // calculate fee growth below
                                  uint256 feeGrowthBelow0X128;
                                  uint256 feeGrowthBelow1X128;
                                  if (tickCurrent >= tickLower) {
                                      feeGrowthBelow0X128 = lower.feeGrowthOutside0X128;
                                      feeGrowthBelow1X128 = lower.feeGrowthOutside1X128;
                                  } else {
                                      feeGrowthBelow0X128 = feeGrowthGlobal0X128 - lower.feeGrowthOutside0X128;
                                      feeGrowthBelow1X128 = feeGrowthGlobal1X128 - lower.feeGrowthOutside1X128;
                                  }
                                  // calculate fee growth above
                                  uint256 feeGrowthAbove0X128;
                                  uint256 feeGrowthAbove1X128;
                                  if (tickCurrent < tickUpper) {
                                      feeGrowthAbove0X128 = upper.feeGrowthOutside0X128;
                                      feeGrowthAbove1X128 = upper.feeGrowthOutside1X128;
                                  } else {
                                      feeGrowthAbove0X128 = feeGrowthGlobal0X128 - upper.feeGrowthOutside0X128;
                                      feeGrowthAbove1X128 = feeGrowthGlobal1X128 - upper.feeGrowthOutside1X128;
                                  }
                                  feeGrowthInside0X128 = feeGrowthGlobal0X128 - feeGrowthBelow0X128 - feeGrowthAbove0X128;
                                  feeGrowthInside1X128 = feeGrowthGlobal1X128 - feeGrowthBelow1X128 - feeGrowthAbove1X128;
                              }
                              /// @notice Updates a tick and returns true if the tick was flipped from initialized to uninitialized, or vice versa
                              /// @param self The mapping containing all tick information for initialized ticks
                              /// @param tick The tick that will be updated
                              /// @param tickCurrent The current tick
                              /// @param liquidityDelta A new amount of liquidity to be added (subtracted) when tick is crossed from left to right (right to left)
                              /// @param feeGrowthGlobal0X128 The all-time global fee growth, per unit of liquidity, in token0
                              /// @param feeGrowthGlobal1X128 The all-time global fee growth, per unit of liquidity, in token1
                              /// @param secondsPerLiquidityCumulativeX128 The all-time seconds per max(1, liquidity) of the pool
                              /// @param time The current block timestamp cast to a uint32
                              /// @param upper true for updating a position's upper tick, or false for updating a position's lower tick
                              /// @param maxLiquidity The maximum liquidity allocation for a single tick
                              /// @return flipped Whether the tick was flipped from initialized to uninitialized, or vice versa
                              function update(
                                  mapping(int24 => Tick.Info) storage self,
                                  int24 tick,
                                  int24 tickCurrent,
                                  int128 liquidityDelta,
                                  uint256 feeGrowthGlobal0X128,
                                  uint256 feeGrowthGlobal1X128,
                                  uint160 secondsPerLiquidityCumulativeX128,
                                  int56 tickCumulative,
                                  uint32 time,
                                  bool upper,
                                  uint128 maxLiquidity
                              ) internal returns (bool flipped) {
                                  Tick.Info storage info = self[tick];
                                  uint128 liquidityGrossBefore = info.liquidityGross;
                                  uint128 liquidityGrossAfter = LiquidityMath.addDelta(liquidityGrossBefore, liquidityDelta);
                                  require(liquidityGrossAfter <= maxLiquidity, 'LO');
                                  flipped = (liquidityGrossAfter == 0) != (liquidityGrossBefore == 0);
                                  if (liquidityGrossBefore == 0) {
                                      // by convention, we assume that all growth before a tick was initialized happened _below_ the tick
                                      if (tick <= tickCurrent) {
                                          info.feeGrowthOutside0X128 = feeGrowthGlobal0X128;
                                          info.feeGrowthOutside1X128 = feeGrowthGlobal1X128;
                                          info.secondsPerLiquidityOutsideX128 = secondsPerLiquidityCumulativeX128;
                                          info.tickCumulativeOutside = tickCumulative;
                                          info.secondsOutside = time;
                                      }
                                      info.initialized = true;
                                  }
                                  info.liquidityGross = liquidityGrossAfter;
                                  // when the lower (upper) tick is crossed left to right (right to left), liquidity must be added (removed)
                                  info.liquidityNet = upper
                                      ? int256(info.liquidityNet).sub(liquidityDelta).toInt128()
                                      : int256(info.liquidityNet).add(liquidityDelta).toInt128();
                              }
                              /// @notice Clears tick data
                              /// @param self The mapping containing all initialized tick information for initialized ticks
                              /// @param tick The tick that will be cleared
                              function clear(mapping(int24 => Tick.Info) storage self, int24 tick) internal {
                                  delete self[tick];
                              }
                              /// @notice Transitions to next tick as needed by price movement
                              /// @param self The mapping containing all tick information for initialized ticks
                              /// @param tick The destination tick of the transition
                              /// @param feeGrowthGlobal0X128 The all-time global fee growth, per unit of liquidity, in token0
                              /// @param feeGrowthGlobal1X128 The all-time global fee growth, per unit of liquidity, in token1
                              /// @param secondsPerLiquidityCumulativeX128 The current seconds per liquidity
                              /// @param time The current block.timestamp
                              /// @return liquidityNet The amount of liquidity added (subtracted) when tick is crossed from left to right (right to left)
                              function cross(
                                  mapping(int24 => Tick.Info) storage self,
                                  int24 tick,
                                  uint256 feeGrowthGlobal0X128,
                                  uint256 feeGrowthGlobal1X128,
                                  uint160 secondsPerLiquidityCumulativeX128,
                                  int56 tickCumulative,
                                  uint32 time
                              ) internal returns (int128 liquidityNet) {
                                  Tick.Info storage info = self[tick];
                                  info.feeGrowthOutside0X128 = feeGrowthGlobal0X128 - info.feeGrowthOutside0X128;
                                  info.feeGrowthOutside1X128 = feeGrowthGlobal1X128 - info.feeGrowthOutside1X128;
                                  info.secondsPerLiquidityOutsideX128 = secondsPerLiquidityCumulativeX128 - info.secondsPerLiquidityOutsideX128;
                                  info.tickCumulativeOutside = tickCumulative - info.tickCumulativeOutside;
                                  info.secondsOutside = time - info.secondsOutside;
                                  liquidityNet = info.liquidityNet;
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './BitMath.sol';
                          /// @title Packed tick initialized state library
                          /// @notice Stores a packed mapping of tick index to its initialized state
                          /// @dev The mapping uses int16 for keys since ticks are represented as int24 and there are 256 (2^8) values per word.
                          library TickBitmap {
                              /// @notice Computes the position in the mapping where the initialized bit for a tick lives
                              /// @param tick The tick for which to compute the position
                              /// @return wordPos The key in the mapping containing the word in which the bit is stored
                              /// @return bitPos The bit position in the word where the flag is stored
                              function position(int24 tick) private pure returns (int16 wordPos, uint8 bitPos) {
                                  wordPos = int16(tick >> 8);
                                  bitPos = uint8(tick % 256);
                              }
                              /// @notice Flips the initialized state for a given tick from false to true, or vice versa
                              /// @param self The mapping in which to flip the tick
                              /// @param tick The tick to flip
                              /// @param tickSpacing The spacing between usable ticks
                              function flipTick(
                                  mapping(int16 => uint256) storage self,
                                  int24 tick,
                                  int24 tickSpacing
                              ) internal {
                                  require(tick % tickSpacing == 0); // ensure that the tick is spaced
                                  (int16 wordPos, uint8 bitPos) = position(tick / tickSpacing);
                                  uint256 mask = 1 << bitPos;
                                  self[wordPos] ^= mask;
                              }
                              /// @notice Returns the next initialized tick contained in the same word (or adjacent word) as the tick that is either
                              /// to the left (less than or equal to) or right (greater than) of the given tick
                              /// @param self The mapping in which to compute the next initialized tick
                              /// @param tick The starting tick
                              /// @param tickSpacing The spacing between usable ticks
                              /// @param lte Whether to search for the next initialized tick to the left (less than or equal to the starting tick)
                              /// @return next The next initialized or uninitialized tick up to 256 ticks away from the current tick
                              /// @return initialized Whether the next tick is initialized, as the function only searches within up to 256 ticks
                              function nextInitializedTickWithinOneWord(
                                  mapping(int16 => uint256) storage self,
                                  int24 tick,
                                  int24 tickSpacing,
                                  bool lte
                              ) internal view returns (int24 next, bool initialized) {
                                  int24 compressed = tick / tickSpacing;
                                  if (tick < 0 && tick % tickSpacing != 0) compressed--; // round towards negative infinity
                                  if (lte) {
                                      (int16 wordPos, uint8 bitPos) = position(compressed);
                                      // all the 1s at or to the right of the current bitPos
                                      uint256 mask = (1 << bitPos) - 1 + (1 << bitPos);
                                      uint256 masked = self[wordPos] & mask;
                                      // if there are no initialized ticks to the right of or at the current tick, return rightmost in the word
                                      initialized = masked != 0;
                                      // overflow/underflow is possible, but prevented externally by limiting both tickSpacing and tick
                                      next = initialized
                                          ? (compressed - int24(bitPos - BitMath.mostSignificantBit(masked))) * tickSpacing
                                          : (compressed - int24(bitPos)) * tickSpacing;
                                  } else {
                                      // start from the word of the next tick, since the current tick state doesn't matter
                                      (int16 wordPos, uint8 bitPos) = position(compressed + 1);
                                      // all the 1s at or to the left of the bitPos
                                      uint256 mask = ~((1 << bitPos) - 1);
                                      uint256 masked = self[wordPos] & mask;
                                      // if there are no initialized ticks to the left of the current tick, return leftmost in the word
                                      initialized = masked != 0;
                                      // overflow/underflow is possible, but prevented externally by limiting both tickSpacing and tick
                                      next = initialized
                                          ? (compressed + 1 + int24(BitMath.leastSignificantBit(masked) - bitPos)) * tickSpacing
                                          : (compressed + 1 + int24(type(uint8).max - bitPos)) * tickSpacing;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './FullMath.sol';
                          import './FixedPoint128.sol';
                          import './LiquidityMath.sol';
                          /// @title Position
                          /// @notice Positions represent an owner address' liquidity between a lower and upper tick boundary
                          /// @dev Positions store additional state for tracking fees owed to the position
                          library Position {
                              // info stored for each user's position
                              struct Info {
                                  // the amount of liquidity owned by this position
                                  uint128 liquidity;
                                  // fee growth per unit of liquidity as of the last update to liquidity or fees owed
                                  uint256 feeGrowthInside0LastX128;
                                  uint256 feeGrowthInside1LastX128;
                                  // the fees owed to the position owner in token0/token1
                                  uint128 tokensOwed0;
                                  uint128 tokensOwed1;
                              }
                              /// @notice Returns the Info struct of a position, given an owner and position boundaries
                              /// @param self The mapping containing all user positions
                              /// @param owner The address of the position owner
                              /// @param tickLower The lower tick boundary of the position
                              /// @param tickUpper The upper tick boundary of the position
                              /// @return position The position info struct of the given owners' position
                              function get(
                                  mapping(bytes32 => Info) storage self,
                                  address owner,
                                  int24 tickLower,
                                  int24 tickUpper
                              ) internal view returns (Position.Info storage position) {
                                  position = self[keccak256(abi.encodePacked(owner, tickLower, tickUpper))];
                              }
                              /// @notice Credits accumulated fees to a user's position
                              /// @param self The individual position to update
                              /// @param liquidityDelta The change in pool liquidity as a result of the position update
                              /// @param feeGrowthInside0X128 The all-time fee growth in token0, per unit of liquidity, inside the position's tick boundaries
                              /// @param feeGrowthInside1X128 The all-time fee growth in token1, per unit of liquidity, inside the position's tick boundaries
                              function update(
                                  Info storage self,
                                  int128 liquidityDelta,
                                  uint256 feeGrowthInside0X128,
                                  uint256 feeGrowthInside1X128
                              ) internal {
                                  Info memory _self = self;
                                  uint128 liquidityNext;
                                  if (liquidityDelta == 0) {
                                      require(_self.liquidity > 0, 'NP'); // disallow pokes for 0 liquidity positions
                                      liquidityNext = _self.liquidity;
                                  } else {
                                      liquidityNext = LiquidityMath.addDelta(_self.liquidity, liquidityDelta);
                                  }
                                  // calculate accumulated fees
                                  uint128 tokensOwed0 =
                                      uint128(
                                          FullMath.mulDiv(
                                              feeGrowthInside0X128 - _self.feeGrowthInside0LastX128,
                                              _self.liquidity,
                                              FixedPoint128.Q128
                                          )
                                      );
                                  uint128 tokensOwed1 =
                                      uint128(
                                          FullMath.mulDiv(
                                              feeGrowthInside1X128 - _self.feeGrowthInside1LastX128,
                                              _self.liquidity,
                                              FixedPoint128.Q128
                                          )
                                      );
                                  // update the position
                                  if (liquidityDelta != 0) self.liquidity = liquidityNext;
                                  self.feeGrowthInside0LastX128 = feeGrowthInside0X128;
                                  self.feeGrowthInside1LastX128 = feeGrowthInside1X128;
                                  if (tokensOwed0 > 0 || tokensOwed1 > 0) {
                                      // overflow is acceptable, have to withdraw before you hit type(uint128).max fees
                                      self.tokensOwed0 += tokensOwed0;
                                      self.tokensOwed1 += tokensOwed1;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          /// @title Oracle
                          /// @notice Provides price and liquidity data useful for a wide variety of system designs
                          /// @dev Instances of stored oracle data, "observations", are collected in the oracle array
                          /// Every pool is initialized with an oracle array length of 1. Anyone can pay the SSTOREs to increase the
                          /// maximum length of the oracle array. New slots will be added when the array is fully populated.
                          /// Observations are overwritten when the full length of the oracle array is populated.
                          /// The most recent observation is available, independent of the length of the oracle array, by passing 0 to observe()
                          library Oracle {
                              struct Observation {
                                  // the block timestamp of the observation
                                  uint32 blockTimestamp;
                                  // the tick accumulator, i.e. tick * time elapsed since the pool was first initialized
                                  int56 tickCumulative;
                                  // the seconds per liquidity, i.e. seconds elapsed / max(1, liquidity) since the pool was first initialized
                                  uint160 secondsPerLiquidityCumulativeX128;
                                  // whether or not the observation is initialized
                                  bool initialized;
                              }
                              /// @notice Transforms a previous observation into a new observation, given the passage of time and the current tick and liquidity values
                              /// @dev blockTimestamp _must_ be chronologically equal to or greater than last.blockTimestamp, safe for 0 or 1 overflows
                              /// @param last The specified observation to be transformed
                              /// @param blockTimestamp The timestamp of the new observation
                              /// @param tick The active tick at the time of the new observation
                              /// @param liquidity The total in-range liquidity at the time of the new observation
                              /// @return Observation The newly populated observation
                              function transform(
                                  Observation memory last,
                                  uint32 blockTimestamp,
                                  int24 tick,
                                  uint128 liquidity
                              ) private pure returns (Observation memory) {
                                  uint32 delta = blockTimestamp - last.blockTimestamp;
                                  return
                                      Observation({
                                          blockTimestamp: blockTimestamp,
                                          tickCumulative: last.tickCumulative + int56(tick) * delta,
                                          secondsPerLiquidityCumulativeX128: last.secondsPerLiquidityCumulativeX128 +
                                              ((uint160(delta) << 128) / (liquidity > 0 ? liquidity : 1)),
                                          initialized: true
                                      });
                              }
                              /// @notice Initialize the oracle array by writing the first slot. Called once for the lifecycle of the observations array
                              /// @param self The stored oracle array
                              /// @param time The time of the oracle initialization, via block.timestamp truncated to uint32
                              /// @return cardinality The number of populated elements in the oracle array
                              /// @return cardinalityNext The new length of the oracle array, independent of population
                              function initialize(Observation[65535] storage self, uint32 time)
                                  internal
                                  returns (uint16 cardinality, uint16 cardinalityNext)
                              {
                                  self[0] = Observation({
                                      blockTimestamp: time,
                                      tickCumulative: 0,
                                      secondsPerLiquidityCumulativeX128: 0,
                                      initialized: true
                                  });
                                  return (1, 1);
                              }
                              /// @notice Writes an oracle observation to the array
                              /// @dev Writable at most once per block. Index represents the most recently written element. cardinality and index must be tracked externally.
                              /// If the index is at the end of the allowable array length (according to cardinality), and the next cardinality
                              /// is greater than the current one, cardinality may be increased. This restriction is created to preserve ordering.
                              /// @param self The stored oracle array
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param blockTimestamp The timestamp of the new observation
                              /// @param tick The active tick at the time of the new observation
                              /// @param liquidity The total in-range liquidity at the time of the new observation
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @param cardinalityNext The new length of the oracle array, independent of population
                              /// @return indexUpdated The new index of the most recently written element in the oracle array
                              /// @return cardinalityUpdated The new cardinality of the oracle array
                              function write(
                                  Observation[65535] storage self,
                                  uint16 index,
                                  uint32 blockTimestamp,
                                  int24 tick,
                                  uint128 liquidity,
                                  uint16 cardinality,
                                  uint16 cardinalityNext
                              ) internal returns (uint16 indexUpdated, uint16 cardinalityUpdated) {
                                  Observation memory last = self[index];
                                  // early return if we've already written an observation this block
                                  if (last.blockTimestamp == blockTimestamp) return (index, cardinality);
                                  // if the conditions are right, we can bump the cardinality
                                  if (cardinalityNext > cardinality && index == (cardinality - 1)) {
                                      cardinalityUpdated = cardinalityNext;
                                  } else {
                                      cardinalityUpdated = cardinality;
                                  }
                                  indexUpdated = (index + 1) % cardinalityUpdated;
                                  self[indexUpdated] = transform(last, blockTimestamp, tick, liquidity);
                              }
                              /// @notice Prepares the oracle array to store up to `next` observations
                              /// @param self The stored oracle array
                              /// @param current The current next cardinality of the oracle array
                              /// @param next The proposed next cardinality which will be populated in the oracle array
                              /// @return next The next cardinality which will be populated in the oracle array
                              function grow(
                                  Observation[65535] storage self,
                                  uint16 current,
                                  uint16 next
                              ) internal returns (uint16) {
                                  require(current > 0, 'I');
                                  // no-op if the passed next value isn't greater than the current next value
                                  if (next <= current) return current;
                                  // store in each slot to prevent fresh SSTOREs in swaps
                                  // this data will not be used because the initialized boolean is still false
                                  for (uint16 i = current; i < next; i++) self[i].blockTimestamp = 1;
                                  return next;
                              }
                              /// @notice comparator for 32-bit timestamps
                              /// @dev safe for 0 or 1 overflows, a and b _must_ be chronologically before or equal to time
                              /// @param time A timestamp truncated to 32 bits
                              /// @param a A comparison timestamp from which to determine the relative position of `time`
                              /// @param b From which to determine the relative position of `time`
                              /// @return bool Whether `a` is chronologically <= `b`
                              function lte(
                                  uint32 time,
                                  uint32 a,
                                  uint32 b
                              ) private pure returns (bool) {
                                  // if there hasn't been overflow, no need to adjust
                                  if (a <= time && b <= time) return a <= b;
                                  uint256 aAdjusted = a > time ? a : a + 2**32;
                                  uint256 bAdjusted = b > time ? b : b + 2**32;
                                  return aAdjusted <= bAdjusted;
                              }
                              /// @notice Fetches the observations beforeOrAt and atOrAfter a target, i.e. where [beforeOrAt, atOrAfter] is satisfied.
                              /// The result may be the same observation, or adjacent observations.
                              /// @dev The answer must be contained in the array, used when the target is located within the stored observation
                              /// boundaries: older than the most recent observation and younger, or the same age as, the oldest observation
                              /// @param self The stored oracle array
                              /// @param time The current block.timestamp
                              /// @param target The timestamp at which the reserved observation should be for
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return beforeOrAt The observation recorded before, or at, the target
                              /// @return atOrAfter The observation recorded at, or after, the target
                              function binarySearch(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32 target,
                                  uint16 index,
                                  uint16 cardinality
                              ) private view returns (Observation memory beforeOrAt, Observation memory atOrAfter) {
                                  uint256 l = (index + 1) % cardinality; // oldest observation
                                  uint256 r = l + cardinality - 1; // newest observation
                                  uint256 i;
                                  while (true) {
                                      i = (l + r) / 2;
                                      beforeOrAt = self[i % cardinality];
                                      // we've landed on an uninitialized tick, keep searching higher (more recently)
                                      if (!beforeOrAt.initialized) {
                                          l = i + 1;
                                          continue;
                                      }
                                      atOrAfter = self[(i + 1) % cardinality];
                                      bool targetAtOrAfter = lte(time, beforeOrAt.blockTimestamp, target);
                                      // check if we've found the answer!
                                      if (targetAtOrAfter && lte(time, target, atOrAfter.blockTimestamp)) break;
                                      if (!targetAtOrAfter) r = i - 1;
                                      else l = i + 1;
                                  }
                              }
                              /// @notice Fetches the observations beforeOrAt and atOrAfter a given target, i.e. where [beforeOrAt, atOrAfter] is satisfied
                              /// @dev Assumes there is at least 1 initialized observation.
                              /// Used by observeSingle() to compute the counterfactual accumulator values as of a given block timestamp.
                              /// @param self The stored oracle array
                              /// @param time The current block.timestamp
                              /// @param target The timestamp at which the reserved observation should be for
                              /// @param tick The active tick at the time of the returned or simulated observation
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param liquidity The total pool liquidity at the time of the call
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return beforeOrAt The observation which occurred at, or before, the given timestamp
                              /// @return atOrAfter The observation which occurred at, or after, the given timestamp
                              function getSurroundingObservations(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32 target,
                                  int24 tick,
                                  uint16 index,
                                  uint128 liquidity,
                                  uint16 cardinality
                              ) private view returns (Observation memory beforeOrAt, Observation memory atOrAfter) {
                                  // optimistically set before to the newest observation
                                  beforeOrAt = self[index];
                                  // if the target is chronologically at or after the newest observation, we can early return
                                  if (lte(time, beforeOrAt.blockTimestamp, target)) {
                                      if (beforeOrAt.blockTimestamp == target) {
                                          // if newest observation equals target, we're in the same block, so we can ignore atOrAfter
                                          return (beforeOrAt, atOrAfter);
                                      } else {
                                          // otherwise, we need to transform
                                          return (beforeOrAt, transform(beforeOrAt, target, tick, liquidity));
                                      }
                                  }
                                  // now, set before to the oldest observation
                                  beforeOrAt = self[(index + 1) % cardinality];
                                  if (!beforeOrAt.initialized) beforeOrAt = self[0];
                                  // ensure that the target is chronologically at or after the oldest observation
                                  require(lte(time, beforeOrAt.blockTimestamp, target), 'OLD');
                                  // if we've reached this point, we have to binary search
                                  return binarySearch(self, time, target, index, cardinality);
                              }
                              /// @dev Reverts if an observation at or before the desired observation timestamp does not exist.
                              /// 0 may be passed as `secondsAgo' to return the current cumulative values.
                              /// If called with a timestamp falling between two observations, returns the counterfactual accumulator values
                              /// at exactly the timestamp between the two observations.
                              /// @param self The stored oracle array
                              /// @param time The current block timestamp
                              /// @param secondsAgo The amount of time to look back, in seconds, at which point to return an observation
                              /// @param tick The current tick
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param liquidity The current in-range pool liquidity
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return tickCumulative The tick * time elapsed since the pool was first initialized, as of `secondsAgo`
                              /// @return secondsPerLiquidityCumulativeX128 The time elapsed / max(1, liquidity) since the pool was first initialized, as of `secondsAgo`
                              function observeSingle(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32 secondsAgo,
                                  int24 tick,
                                  uint16 index,
                                  uint128 liquidity,
                                  uint16 cardinality
                              ) internal view returns (int56 tickCumulative, uint160 secondsPerLiquidityCumulativeX128) {
                                  if (secondsAgo == 0) {
                                      Observation memory last = self[index];
                                      if (last.blockTimestamp != time) last = transform(last, time, tick, liquidity);
                                      return (last.tickCumulative, last.secondsPerLiquidityCumulativeX128);
                                  }
                                  uint32 target = time - secondsAgo;
                                  (Observation memory beforeOrAt, Observation memory atOrAfter) =
                                      getSurroundingObservations(self, time, target, tick, index, liquidity, cardinality);
                                  if (target == beforeOrAt.blockTimestamp) {
                                      // we're at the left boundary
                                      return (beforeOrAt.tickCumulative, beforeOrAt.secondsPerLiquidityCumulativeX128);
                                  } else if (target == atOrAfter.blockTimestamp) {
                                      // we're at the right boundary
                                      return (atOrAfter.tickCumulative, atOrAfter.secondsPerLiquidityCumulativeX128);
                                  } else {
                                      // we're in the middle
                                      uint32 observationTimeDelta = atOrAfter.blockTimestamp - beforeOrAt.blockTimestamp;
                                      uint32 targetDelta = target - beforeOrAt.blockTimestamp;
                                      return (
                                          beforeOrAt.tickCumulative +
                                              ((atOrAfter.tickCumulative - beforeOrAt.tickCumulative) / observationTimeDelta) *
                                              targetDelta,
                                          beforeOrAt.secondsPerLiquidityCumulativeX128 +
                                              uint160(
                                                  (uint256(
                                                      atOrAfter.secondsPerLiquidityCumulativeX128 - beforeOrAt.secondsPerLiquidityCumulativeX128
                                                  ) * targetDelta) / observationTimeDelta
                                              )
                                      );
                                  }
                              }
                              /// @notice Returns the accumulator values as of each time seconds ago from the given time in the array of `secondsAgos`
                              /// @dev Reverts if `secondsAgos` > oldest observation
                              /// @param self The stored oracle array
                              /// @param time The current block.timestamp
                              /// @param secondsAgos Each amount of time to look back, in seconds, at which point to return an observation
                              /// @param tick The current tick
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param liquidity The current in-range pool liquidity
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return tickCumulatives The tick * time elapsed since the pool was first initialized, as of each `secondsAgo`
                              /// @return secondsPerLiquidityCumulativeX128s The cumulative seconds / max(1, liquidity) since the pool was first initialized, as of each `secondsAgo`
                              function observe(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32[] memory secondsAgos,
                                  int24 tick,
                                  uint16 index,
                                  uint128 liquidity,
                                  uint16 cardinality
                              ) internal view returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s) {
                                  require(cardinality > 0, 'I');
                                  tickCumulatives = new int56[](secondsAgos.length);
                                  secondsPerLiquidityCumulativeX128s = new uint160[](secondsAgos.length);
                                  for (uint256 i = 0; i < secondsAgos.length; i++) {
                                      (tickCumulatives[i], secondsPerLiquidityCumulativeX128s[i]) = observeSingle(
                                          self,
                                          time,
                                          secondsAgos[i],
                                          tick,
                                          index,
                                          liquidity,
                                          cardinality
                                      );
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.4.0;
                          /// @title Contains 512-bit math functions
                          /// @notice Facilitates multiplication and division that can have overflow of an intermediate value without any loss of precision
                          /// @dev Handles "phantom overflow" i.e., allows multiplication and division where an intermediate value overflows 256 bits
                          library FullMath {
                              /// @notice Calculates floor(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
                              /// @param a The multiplicand
                              /// @param b The multiplier
                              /// @param denominator The divisor
                              /// @return result The 256-bit result
                              /// @dev Credit to Remco Bloemen under MIT license https://xn--2-umb.com/21/muldiv
                              function mulDiv(
                                  uint256 a,
                                  uint256 b,
                                  uint256 denominator
                              ) internal pure returns (uint256 result) {
                                  // 512-bit multiply [prod1 prod0] = a * b
                                  // Compute the product mod 2**256 and mod 2**256 - 1
                                  // then use the Chinese Remainder Theorem to reconstruct
                                  // the 512 bit result. The result is stored in two 256
                                  // variables such that product = prod1 * 2**256 + prod0
                                  uint256 prod0; // Least significant 256 bits of the product
                                  uint256 prod1; // Most significant 256 bits of the product
                                  assembly {
                                      let mm := mulmod(a, b, not(0))
                                      prod0 := mul(a, b)
                                      prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                                  }
                                  // Handle non-overflow cases, 256 by 256 division
                                  if (prod1 == 0) {
                                      require(denominator > 0);
                                      assembly {
                                          result := div(prod0, denominator)
                                      }
                                      return result;
                                  }
                                  // Make sure the result is less than 2**256.
                                  // Also prevents denominator == 0
                                  require(denominator > prod1);
                                  ///////////////////////////////////////////////
                                  // 512 by 256 division.
                                  ///////////////////////////////////////////////
                                  // Make division exact by subtracting the remainder from [prod1 prod0]
                                  // Compute remainder using mulmod
                                  uint256 remainder;
                                  assembly {
                                      remainder := mulmod(a, b, denominator)
                                  }
                                  // Subtract 256 bit number from 512 bit number
                                  assembly {
                                      prod1 := sub(prod1, gt(remainder, prod0))
                                      prod0 := sub(prod0, remainder)
                                  }
                                  // Factor powers of two out of denominator
                                  // Compute largest power of two divisor of denominator.
                                  // Always >= 1.
                                  uint256 twos = -denominator & denominator;
                                  // Divide denominator by power of two
                                  assembly {
                                      denominator := div(denominator, twos)
                                  }
                                  // Divide [prod1 prod0] by the factors of two
                                  assembly {
                                      prod0 := div(prod0, twos)
                                  }
                                  // Shift in bits from prod1 into prod0. For this we need
                                  // to flip `twos` such that it is 2**256 / twos.
                                  // If twos is zero, then it becomes one
                                  assembly {
                                      twos := add(div(sub(0, twos), twos), 1)
                                  }
                                  prod0 |= prod1 * twos;
                                  // Invert denominator mod 2**256
                                  // Now that denominator is an odd number, it has an inverse
                                  // modulo 2**256 such that denominator * inv = 1 mod 2**256.
                                  // Compute the inverse by starting with a seed that is correct
                                  // correct for four bits. That is, denominator * inv = 1 mod 2**4
                                  uint256 inv = (3 * denominator) ^ 2;
                                  // Now use Newton-Raphson iteration to improve the precision.
                                  // Thanks to Hensel's lifting lemma, this also works in modular
                                  // arithmetic, doubling the correct bits in each step.
                                  inv *= 2 - denominator * inv; // inverse mod 2**8
                                  inv *= 2 - denominator * inv; // inverse mod 2**16
                                  inv *= 2 - denominator * inv; // inverse mod 2**32
                                  inv *= 2 - denominator * inv; // inverse mod 2**64
                                  inv *= 2 - denominator * inv; // inverse mod 2**128
                                  inv *= 2 - denominator * inv; // inverse mod 2**256
                                  // Because the division is now exact we can divide by multiplying
                                  // with the modular inverse of denominator. This will give us the
                                  // correct result modulo 2**256. Since the precoditions guarantee
                                  // that the outcome is less than 2**256, this is the final result.
                                  // We don't need to compute the high bits of the result and prod1
                                  // is no longer required.
                                  result = prod0 * inv;
                                  return result;
                              }
                              /// @notice Calculates ceil(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
                              /// @param a The multiplicand
                              /// @param b The multiplier
                              /// @param denominator The divisor
                              /// @return result The 256-bit result
                              function mulDivRoundingUp(
                                  uint256 a,
                                  uint256 b,
                                  uint256 denominator
                              ) internal pure returns (uint256 result) {
                                  result = mulDiv(a, b, denominator);
                                  if (mulmod(a, b, denominator) > 0) {
                                      require(result < type(uint256).max);
                                      result++;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.4.0;
                          /// @title FixedPoint128
                          /// @notice A library for handling binary fixed point numbers, see https://en.wikipedia.org/wiki/Q_(number_format)
                          library FixedPoint128 {
                              uint256 internal constant Q128 = 0x100000000000000000000000000000000;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.6.0;
                          import '../interfaces/IERC20Minimal.sol';
                          /// @title TransferHelper
                          /// @notice Contains helper methods for interacting with ERC20 tokens that do not consistently return true/false
                          library TransferHelper {
                              /// @notice Transfers tokens from msg.sender to a recipient
                              /// @dev Calls transfer on token contract, errors with TF if transfer fails
                              /// @param token The contract address of the token which will be transferred
                              /// @param to The recipient of the transfer
                              /// @param value The value of the transfer
                              function safeTransfer(
                                  address token,
                                  address to,
                                  uint256 value
                              ) internal {
                                  (bool success, bytes memory data) =
                                      token.call(abi.encodeWithSelector(IERC20Minimal.transfer.selector, to, value));
                                  require(success && (data.length == 0 || abi.decode(data, (bool))), 'TF');
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math library for computing sqrt prices from ticks and vice versa
                          /// @notice Computes sqrt price for ticks of size 1.0001, i.e. sqrt(1.0001^tick) as fixed point Q64.96 numbers. Supports
                          /// prices between 2**-128 and 2**128
                          library TickMath {
                              /// @dev The minimum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**-128
                              int24 internal constant MIN_TICK = -887272;
                              /// @dev The maximum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**128
                              int24 internal constant MAX_TICK = -MIN_TICK;
                              /// @dev The minimum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MIN_TICK)
                              uint160 internal constant MIN_SQRT_RATIO = 4295128739;
                              /// @dev The maximum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MAX_TICK)
                              uint160 internal constant MAX_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
                              /// @notice Calculates sqrt(1.0001^tick) * 2^96
                              /// @dev Throws if |tick| > max tick
                              /// @param tick The input tick for the above formula
                              /// @return sqrtPriceX96 A Fixed point Q64.96 number representing the sqrt of the ratio of the two assets (token1/token0)
                              /// at the given tick
                              function getSqrtRatioAtTick(int24 tick) internal pure returns (uint160 sqrtPriceX96) {
                                  uint256 absTick = tick < 0 ? uint256(-int256(tick)) : uint256(int256(tick));
                                  require(absTick <= uint256(MAX_TICK), 'T');
                                  uint256 ratio = absTick & 0x1 != 0 ? 0xfffcb933bd6fad37aa2d162d1a594001 : 0x100000000000000000000000000000000;
                                  if (absTick & 0x2 != 0) ratio = (ratio * 0xfff97272373d413259a46990580e213a) >> 128;
                                  if (absTick & 0x4 != 0) ratio = (ratio * 0xfff2e50f5f656932ef12357cf3c7fdcc) >> 128;
                                  if (absTick & 0x8 != 0) ratio = (ratio * 0xffe5caca7e10e4e61c3624eaa0941cd0) >> 128;
                                  if (absTick & 0x10 != 0) ratio = (ratio * 0xffcb9843d60f6159c9db58835c926644) >> 128;
                                  if (absTick & 0x20 != 0) ratio = (ratio * 0xff973b41fa98c081472e6896dfb254c0) >> 128;
                                  if (absTick & 0x40 != 0) ratio = (ratio * 0xff2ea16466c96a3843ec78b326b52861) >> 128;
                                  if (absTick & 0x80 != 0) ratio = (ratio * 0xfe5dee046a99a2a811c461f1969c3053) >> 128;
                                  if (absTick & 0x100 != 0) ratio = (ratio * 0xfcbe86c7900a88aedcffc83b479aa3a4) >> 128;
                                  if (absTick & 0x200 != 0) ratio = (ratio * 0xf987a7253ac413176f2b074cf7815e54) >> 128;
                                  if (absTick & 0x400 != 0) ratio = (ratio * 0xf3392b0822b70005940c7a398e4b70f3) >> 128;
                                  if (absTick & 0x800 != 0) ratio = (ratio * 0xe7159475a2c29b7443b29c7fa6e889d9) >> 128;
                                  if (absTick & 0x1000 != 0) ratio = (ratio * 0xd097f3bdfd2022b8845ad8f792aa5825) >> 128;
                                  if (absTick & 0x2000 != 0) ratio = (ratio * 0xa9f746462d870fdf8a65dc1f90e061e5) >> 128;
                                  if (absTick & 0x4000 != 0) ratio = (ratio * 0x70d869a156d2a1b890bb3df62baf32f7) >> 128;
                                  if (absTick & 0x8000 != 0) ratio = (ratio * 0x31be135f97d08fd981231505542fcfa6) >> 128;
                                  if (absTick & 0x10000 != 0) ratio = (ratio * 0x9aa508b5b7a84e1c677de54f3e99bc9) >> 128;
                                  if (absTick & 0x20000 != 0) ratio = (ratio * 0x5d6af8dedb81196699c329225ee604) >> 128;
                                  if (absTick & 0x40000 != 0) ratio = (ratio * 0x2216e584f5fa1ea926041bedfe98) >> 128;
                                  if (absTick & 0x80000 != 0) ratio = (ratio * 0x48a170391f7dc42444e8fa2) >> 128;
                                  if (tick > 0) ratio = type(uint256).max / ratio;
                                  // this divides by 1<<32 rounding up to go from a Q128.128 to a Q128.96.
                                  // we then downcast because we know the result always fits within 160 bits due to our tick input constraint
                                  // we round up in the division so getTickAtSqrtRatio of the output price is always consistent
                                  sqrtPriceX96 = uint160((ratio >> 32) + (ratio % (1 << 32) == 0 ? 0 : 1));
                              }
                              /// @notice Calculates the greatest tick value such that getRatioAtTick(tick) <= ratio
                              /// @dev Throws in case sqrtPriceX96 < MIN_SQRT_RATIO, as MIN_SQRT_RATIO is the lowest value getRatioAtTick may
                              /// ever return.
                              /// @param sqrtPriceX96 The sqrt ratio for which to compute the tick as a Q64.96
                              /// @return tick The greatest tick for which the ratio is less than or equal to the input ratio
                              function getTickAtSqrtRatio(uint160 sqrtPriceX96) internal pure returns (int24 tick) {
                                  // second inequality must be < because the price can never reach the price at the max tick
                                  require(sqrtPriceX96 >= MIN_SQRT_RATIO && sqrtPriceX96 < MAX_SQRT_RATIO, 'R');
                                  uint256 ratio = uint256(sqrtPriceX96) << 32;
                                  uint256 r = ratio;
                                  uint256 msb = 0;
                                  assembly {
                                      let f := shl(7, gt(r, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(6, gt(r, 0xFFFFFFFFFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(5, gt(r, 0xFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(4, gt(r, 0xFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(3, gt(r, 0xFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(2, gt(r, 0xF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(1, gt(r, 0x3))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := gt(r, 0x1)
                                      msb := or(msb, f)
                                  }
                                  if (msb >= 128) r = ratio >> (msb - 127);
                                  else r = ratio << (127 - msb);
                                  int256 log_2 = (int256(msb) - 128) << 64;
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(63, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(62, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(61, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(60, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(59, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(58, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(57, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(56, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(55, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(54, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(53, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(52, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(51, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(50, f))
                                  }
                                  int256 log_sqrt10001 = log_2 * 255738958999603826347141; // 128.128 number
                                  int24 tickLow = int24((log_sqrt10001 - 3402992956809132418596140100660247210) >> 128);
                                  int24 tickHi = int24((log_sqrt10001 + 291339464771989622907027621153398088495) >> 128);
                                  tick = tickLow == tickHi ? tickLow : getSqrtRatioAtTick(tickHi) <= sqrtPriceX96 ? tickHi : tickLow;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math library for liquidity
                          library LiquidityMath {
                              /// @notice Add a signed liquidity delta to liquidity and revert if it overflows or underflows
                              /// @param x The liquidity before change
                              /// @param y The delta by which liquidity should be changed
                              /// @return z The liquidity delta
                              function addDelta(uint128 x, int128 y) internal pure returns (uint128 z) {
                                  if (y < 0) {
                                      require((z = x - uint128(-y)) < x, 'LS');
                                  } else {
                                      require((z = x + uint128(y)) >= x, 'LA');
                                  }
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './LowGasSafeMath.sol';
                          import './SafeCast.sol';
                          import './FullMath.sol';
                          import './UnsafeMath.sol';
                          import './FixedPoint96.sol';
                          /// @title Functions based on Q64.96 sqrt price and liquidity
                          /// @notice Contains the math that uses square root of price as a Q64.96 and liquidity to compute deltas
                          library SqrtPriceMath {
                              using LowGasSafeMath for uint256;
                              using SafeCast for uint256;
                              /// @notice Gets the next sqrt price given a delta of token0
                              /// @dev Always rounds up, because in the exact output case (increasing price) we need to move the price at least
                              /// far enough to get the desired output amount, and in the exact input case (decreasing price) we need to move the
                              /// price less in order to not send too much output.
                              /// The most precise formula for this is liquidity * sqrtPX96 / (liquidity +- amount * sqrtPX96),
                              /// if this is impossible because of overflow, we calculate liquidity / (liquidity / sqrtPX96 +- amount).
                              /// @param sqrtPX96 The starting price, i.e. before accounting for the token0 delta
                              /// @param liquidity The amount of usable liquidity
                              /// @param amount How much of token0 to add or remove from virtual reserves
                              /// @param add Whether to add or remove the amount of token0
                              /// @return The price after adding or removing amount, depending on add
                              function getNextSqrtPriceFromAmount0RoundingUp(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amount,
                                  bool add
                              ) internal pure returns (uint160) {
                                  // we short circuit amount == 0 because the result is otherwise not guaranteed to equal the input price
                                  if (amount == 0) return sqrtPX96;
                                  uint256 numerator1 = uint256(liquidity) << FixedPoint96.RESOLUTION;
                                  if (add) {
                                      uint256 product;
                                      if ((product = amount * sqrtPX96) / amount == sqrtPX96) {
                                          uint256 denominator = numerator1 + product;
                                          if (denominator >= numerator1)
                                              // always fits in 160 bits
                                              return uint160(FullMath.mulDivRoundingUp(numerator1, sqrtPX96, denominator));
                                      }
                                      return uint160(UnsafeMath.divRoundingUp(numerator1, (numerator1 / sqrtPX96).add(amount)));
                                  } else {
                                      uint256 product;
                                      // if the product overflows, we know the denominator underflows
                                      // in addition, we must check that the denominator does not underflow
                                      require((product = amount * sqrtPX96) / amount == sqrtPX96 && numerator1 > product);
                                      uint256 denominator = numerator1 - product;
                                      return FullMath.mulDivRoundingUp(numerator1, sqrtPX96, denominator).toUint160();
                                  }
                              }
                              /// @notice Gets the next sqrt price given a delta of token1
                              /// @dev Always rounds down, because in the exact output case (decreasing price) we need to move the price at least
                              /// far enough to get the desired output amount, and in the exact input case (increasing price) we need to move the
                              /// price less in order to not send too much output.
                              /// The formula we compute is within <1 wei of the lossless version: sqrtPX96 +- amount / liquidity
                              /// @param sqrtPX96 The starting price, i.e., before accounting for the token1 delta
                              /// @param liquidity The amount of usable liquidity
                              /// @param amount How much of token1 to add, or remove, from virtual reserves
                              /// @param add Whether to add, or remove, the amount of token1
                              /// @return The price after adding or removing `amount`
                              function getNextSqrtPriceFromAmount1RoundingDown(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amount,
                                  bool add
                              ) internal pure returns (uint160) {
                                  // if we're adding (subtracting), rounding down requires rounding the quotient down (up)
                                  // in both cases, avoid a mulDiv for most inputs
                                  if (add) {
                                      uint256 quotient =
                                          (
                                              amount <= type(uint160).max
                                                  ? (amount << FixedPoint96.RESOLUTION) / liquidity
                                                  : FullMath.mulDiv(amount, FixedPoint96.Q96, liquidity)
                                          );
                                      return uint256(sqrtPX96).add(quotient).toUint160();
                                  } else {
                                      uint256 quotient =
                                          (
                                              amount <= type(uint160).max
                                                  ? UnsafeMath.divRoundingUp(amount << FixedPoint96.RESOLUTION, liquidity)
                                                  : FullMath.mulDivRoundingUp(amount, FixedPoint96.Q96, liquidity)
                                          );
                                      require(sqrtPX96 > quotient);
                                      // always fits 160 bits
                                      return uint160(sqrtPX96 - quotient);
                                  }
                              }
                              /// @notice Gets the next sqrt price given an input amount of token0 or token1
                              /// @dev Throws if price or liquidity are 0, or if the next price is out of bounds
                              /// @param sqrtPX96 The starting price, i.e., before accounting for the input amount
                              /// @param liquidity The amount of usable liquidity
                              /// @param amountIn How much of token0, or token1, is being swapped in
                              /// @param zeroForOne Whether the amount in is token0 or token1
                              /// @return sqrtQX96 The price after adding the input amount to token0 or token1
                              function getNextSqrtPriceFromInput(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amountIn,
                                  bool zeroForOne
                              ) internal pure returns (uint160 sqrtQX96) {
                                  require(sqrtPX96 > 0);
                                  require(liquidity > 0);
                                  // round to make sure that we don't pass the target price
                                  return
                                      zeroForOne
                                          ? getNextSqrtPriceFromAmount0RoundingUp(sqrtPX96, liquidity, amountIn, true)
                                          : getNextSqrtPriceFromAmount1RoundingDown(sqrtPX96, liquidity, amountIn, true);
                              }
                              /// @notice Gets the next sqrt price given an output amount of token0 or token1
                              /// @dev Throws if price or liquidity are 0 or the next price is out of bounds
                              /// @param sqrtPX96 The starting price before accounting for the output amount
                              /// @param liquidity The amount of usable liquidity
                              /// @param amountOut How much of token0, or token1, is being swapped out
                              /// @param zeroForOne Whether the amount out is token0 or token1
                              /// @return sqrtQX96 The price after removing the output amount of token0 or token1
                              function getNextSqrtPriceFromOutput(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amountOut,
                                  bool zeroForOne
                              ) internal pure returns (uint160 sqrtQX96) {
                                  require(sqrtPX96 > 0);
                                  require(liquidity > 0);
                                  // round to make sure that we pass the target price
                                  return
                                      zeroForOne
                                          ? getNextSqrtPriceFromAmount1RoundingDown(sqrtPX96, liquidity, amountOut, false)
                                          : getNextSqrtPriceFromAmount0RoundingUp(sqrtPX96, liquidity, amountOut, false);
                              }
                              /// @notice Gets the amount0 delta between two prices
                              /// @dev Calculates liquidity / sqrt(lower) - liquidity / sqrt(upper),
                              /// i.e. liquidity * (sqrt(upper) - sqrt(lower)) / (sqrt(upper) * sqrt(lower))
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The amount of usable liquidity
                              /// @param roundUp Whether to round the amount up or down
                              /// @return amount0 Amount of token0 required to cover a position of size liquidity between the two passed prices
                              function getAmount0Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  uint128 liquidity,
                                  bool roundUp
                              ) internal pure returns (uint256 amount0) {
                                  if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
                                  uint256 numerator1 = uint256(liquidity) << FixedPoint96.RESOLUTION;
                                  uint256 numerator2 = sqrtRatioBX96 - sqrtRatioAX96;
                                  require(sqrtRatioAX96 > 0);
                                  return
                                      roundUp
                                          ? UnsafeMath.divRoundingUp(
                                              FullMath.mulDivRoundingUp(numerator1, numerator2, sqrtRatioBX96),
                                              sqrtRatioAX96
                                          )
                                          : FullMath.mulDiv(numerator1, numerator2, sqrtRatioBX96) / sqrtRatioAX96;
                              }
                              /// @notice Gets the amount1 delta between two prices
                              /// @dev Calculates liquidity * (sqrt(upper) - sqrt(lower))
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The amount of usable liquidity
                              /// @param roundUp Whether to round the amount up, or down
                              /// @return amount1 Amount of token1 required to cover a position of size liquidity between the two passed prices
                              function getAmount1Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  uint128 liquidity,
                                  bool roundUp
                              ) internal pure returns (uint256 amount1) {
                                  if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
                                  return
                                      roundUp
                                          ? FullMath.mulDivRoundingUp(liquidity, sqrtRatioBX96 - sqrtRatioAX96, FixedPoint96.Q96)
                                          : FullMath.mulDiv(liquidity, sqrtRatioBX96 - sqrtRatioAX96, FixedPoint96.Q96);
                              }
                              /// @notice Helper that gets signed token0 delta
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The change in liquidity for which to compute the amount0 delta
                              /// @return amount0 Amount of token0 corresponding to the passed liquidityDelta between the two prices
                              function getAmount0Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  int128 liquidity
                              ) internal pure returns (int256 amount0) {
                                  return
                                      liquidity < 0
                                          ? -getAmount0Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(-liquidity), false).toInt256()
                                          : getAmount0Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(liquidity), true).toInt256();
                              }
                              /// @notice Helper that gets signed token1 delta
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The change in liquidity for which to compute the amount1 delta
                              /// @return amount1 Amount of token1 corresponding to the passed liquidityDelta between the two prices
                              function getAmount1Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  int128 liquidity
                              ) internal pure returns (int256 amount1) {
                                  return
                                      liquidity < 0
                                          ? -getAmount1Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(-liquidity), false).toInt256()
                                          : getAmount1Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(liquidity), true).toInt256();
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './FullMath.sol';
                          import './SqrtPriceMath.sol';
                          /// @title Computes the result of a swap within ticks
                          /// @notice Contains methods for computing the result of a swap within a single tick price range, i.e., a single tick.
                          library SwapMath {
                              /// @notice Computes the result of swapping some amount in, or amount out, given the parameters of the swap
                              /// @dev The fee, plus the amount in, will never exceed the amount remaining if the swap's `amountSpecified` is positive
                              /// @param sqrtRatioCurrentX96 The current sqrt price of the pool
                              /// @param sqrtRatioTargetX96 The price that cannot be exceeded, from which the direction of the swap is inferred
                              /// @param liquidity The usable liquidity
                              /// @param amountRemaining How much input or output amount is remaining to be swapped in/out
                              /// @param feePips The fee taken from the input amount, expressed in hundredths of a bip
                              /// @return sqrtRatioNextX96 The price after swapping the amount in/out, not to exceed the price target
                              /// @return amountIn The amount to be swapped in, of either token0 or token1, based on the direction of the swap
                              /// @return amountOut The amount to be received, of either token0 or token1, based on the direction of the swap
                              /// @return feeAmount The amount of input that will be taken as a fee
                              function computeSwapStep(
                                  uint160 sqrtRatioCurrentX96,
                                  uint160 sqrtRatioTargetX96,
                                  uint128 liquidity,
                                  int256 amountRemaining,
                                  uint24 feePips
                              )
                                  internal
                                  pure
                                  returns (
                                      uint160 sqrtRatioNextX96,
                                      uint256 amountIn,
                                      uint256 amountOut,
                                      uint256 feeAmount
                                  )
                              {
                                  bool zeroForOne = sqrtRatioCurrentX96 >= sqrtRatioTargetX96;
                                  bool exactIn = amountRemaining >= 0;
                                  if (exactIn) {
                                      uint256 amountRemainingLessFee = FullMath.mulDiv(uint256(amountRemaining), 1e6 - feePips, 1e6);
                                      amountIn = zeroForOne
                                          ? SqrtPriceMath.getAmount0Delta(sqrtRatioTargetX96, sqrtRatioCurrentX96, liquidity, true)
                                          : SqrtPriceMath.getAmount1Delta(sqrtRatioCurrentX96, sqrtRatioTargetX96, liquidity, true);
                                      if (amountRemainingLessFee >= amountIn) sqrtRatioNextX96 = sqrtRatioTargetX96;
                                      else
                                          sqrtRatioNextX96 = SqrtPriceMath.getNextSqrtPriceFromInput(
                                              sqrtRatioCurrentX96,
                                              liquidity,
                                              amountRemainingLessFee,
                                              zeroForOne
                                          );
                                  } else {
                                      amountOut = zeroForOne
                                          ? SqrtPriceMath.getAmount1Delta(sqrtRatioTargetX96, sqrtRatioCurrentX96, liquidity, false)
                                          : SqrtPriceMath.getAmount0Delta(sqrtRatioCurrentX96, sqrtRatioTargetX96, liquidity, false);
                                      if (uint256(-amountRemaining) >= amountOut) sqrtRatioNextX96 = sqrtRatioTargetX96;
                                      else
                                          sqrtRatioNextX96 = SqrtPriceMath.getNextSqrtPriceFromOutput(
                                              sqrtRatioCurrentX96,
                                              liquidity,
                                              uint256(-amountRemaining),
                                              zeroForOne
                                          );
                                  }
                                  bool max = sqrtRatioTargetX96 == sqrtRatioNextX96;
                                  // get the input/output amounts
                                  if (zeroForOne) {
                                      amountIn = max && exactIn
                                          ? amountIn
                                          : SqrtPriceMath.getAmount0Delta(sqrtRatioNextX96, sqrtRatioCurrentX96, liquidity, true);
                                      amountOut = max && !exactIn
                                          ? amountOut
                                          : SqrtPriceMath.getAmount1Delta(sqrtRatioNextX96, sqrtRatioCurrentX96, liquidity, false);
                                  } else {
                                      amountIn = max && exactIn
                                          ? amountIn
                                          : SqrtPriceMath.getAmount1Delta(sqrtRatioCurrentX96, sqrtRatioNextX96, liquidity, true);
                                      amountOut = max && !exactIn
                                          ? amountOut
                                          : SqrtPriceMath.getAmount0Delta(sqrtRatioCurrentX96, sqrtRatioNextX96, liquidity, false);
                                  }
                                  // cap the output amount to not exceed the remaining output amount
                                  if (!exactIn && amountOut > uint256(-amountRemaining)) {
                                      amountOut = uint256(-amountRemaining);
                                  }
                                  if (exactIn && sqrtRatioNextX96 != sqrtRatioTargetX96) {
                                      // we didn't reach the target, so take the remainder of the maximum input as fee
                                      feeAmount = uint256(amountRemaining) - amountIn;
                                  } else {
                                      feeAmount = FullMath.mulDivRoundingUp(amountIn, feePips, 1e6 - feePips);
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title An interface for a contract that is capable of deploying Uniswap V3 Pools
                          /// @notice A contract that constructs a pool must implement this to pass arguments to the pool
                          /// @dev This is used to avoid having constructor arguments in the pool contract, which results in the init code hash
                          /// of the pool being constant allowing the CREATE2 address of the pool to be cheaply computed on-chain
                          interface IUniswapV3PoolDeployer {
                              /// @notice Get the parameters to be used in constructing the pool, set transiently during pool creation.
                              /// @dev Called by the pool constructor to fetch the parameters of the pool
                              /// Returns factory The factory address
                              /// Returns token0 The first token of the pool by address sort order
                              /// Returns token1 The second token of the pool by address sort order
                              /// Returns fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// Returns tickSpacing The minimum number of ticks between initialized ticks
                              function parameters()
                                  external
                                  view
                                  returns (
                                      address factory,
                                      address token0,
                                      address token1,
                                      uint24 fee,
                                      int24 tickSpacing
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title The interface for the Uniswap V3 Factory
                          /// @notice The Uniswap V3 Factory facilitates creation of Uniswap V3 pools and control over the protocol fees
                          interface IUniswapV3Factory {
                              /// @notice Emitted when the owner of the factory is changed
                              /// @param oldOwner The owner before the owner was changed
                              /// @param newOwner The owner after the owner was changed
                              event OwnerChanged(address indexed oldOwner, address indexed newOwner);
                              /// @notice Emitted when a pool is created
                              /// @param token0 The first token of the pool by address sort order
                              /// @param token1 The second token of the pool by address sort order
                              /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// @param tickSpacing The minimum number of ticks between initialized ticks
                              /// @param pool The address of the created pool
                              event PoolCreated(
                                  address indexed token0,
                                  address indexed token1,
                                  uint24 indexed fee,
                                  int24 tickSpacing,
                                  address pool
                              );
                              /// @notice Emitted when a new fee amount is enabled for pool creation via the factory
                              /// @param fee The enabled fee, denominated in hundredths of a bip
                              /// @param tickSpacing The minimum number of ticks between initialized ticks for pools created with the given fee
                              event FeeAmountEnabled(uint24 indexed fee, int24 indexed tickSpacing);
                              /// @notice Returns the current owner of the factory
                              /// @dev Can be changed by the current owner via setOwner
                              /// @return The address of the factory owner
                              function owner() external view returns (address);
                              /// @notice Returns the tick spacing for a given fee amount, if enabled, or 0 if not enabled
                              /// @dev A fee amount can never be removed, so this value should be hard coded or cached in the calling context
                              /// @param fee The enabled fee, denominated in hundredths of a bip. Returns 0 in case of unenabled fee
                              /// @return The tick spacing
                              function feeAmountTickSpacing(uint24 fee) external view returns (int24);
                              /// @notice Returns the pool address for a given pair of tokens and a fee, or address 0 if it does not exist
                              /// @dev tokenA and tokenB may be passed in either token0/token1 or token1/token0 order
                              /// @param tokenA The contract address of either token0 or token1
                              /// @param tokenB The contract address of the other token
                              /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// @return pool The pool address
                              function getPool(
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) external view returns (address pool);
                              /// @notice Creates a pool for the given two tokens and fee
                              /// @param tokenA One of the two tokens in the desired pool
                              /// @param tokenB The other of the two tokens in the desired pool
                              /// @param fee The desired fee for the pool
                              /// @dev tokenA and tokenB may be passed in either order: token0/token1 or token1/token0. tickSpacing is retrieved
                              /// from the fee. The call will revert if the pool already exists, the fee is invalid, or the token arguments
                              /// are invalid.
                              /// @return pool The address of the newly created pool
                              function createPool(
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) external returns (address pool);
                              /// @notice Updates the owner of the factory
                              /// @dev Must be called by the current owner
                              /// @param _owner The new owner of the factory
                              function setOwner(address _owner) external;
                              /// @notice Enables a fee amount with the given tickSpacing
                              /// @dev Fee amounts may never be removed once enabled
                              /// @param fee The fee amount to enable, denominated in hundredths of a bip (i.e. 1e-6)
                              /// @param tickSpacing The spacing between ticks to be enforced for all pools created with the given fee amount
                              function enableFeeAmount(uint24 fee, int24 tickSpacing) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Minimal ERC20 interface for Uniswap
                          /// @notice Contains a subset of the full ERC20 interface that is used in Uniswap V3
                          interface IERC20Minimal {
                              /// @notice Returns the balance of a token
                              /// @param account The account for which to look up the number of tokens it has, i.e. its balance
                              /// @return The number of tokens held by the account
                              function balanceOf(address account) external view returns (uint256);
                              /// @notice Transfers the amount of token from the `msg.sender` to the recipient
                              /// @param recipient The account that will receive the amount transferred
                              /// @param amount The number of tokens to send from the sender to the recipient
                              /// @return Returns true for a successful transfer, false for an unsuccessful transfer
                              function transfer(address recipient, uint256 amount) external returns (bool);
                              /// @notice Returns the current allowance given to a spender by an owner
                              /// @param owner The account of the token owner
                              /// @param spender The account of the token spender
                              /// @return The current allowance granted by `owner` to `spender`
                              function allowance(address owner, address spender) external view returns (uint256);
                              /// @notice Sets the allowance of a spender from the `msg.sender` to the value `amount`
                              /// @param spender The account which will be allowed to spend a given amount of the owners tokens
                              /// @param amount The amount of tokens allowed to be used by `spender`
                              /// @return Returns true for a successful approval, false for unsuccessful
                              function approve(address spender, uint256 amount) external returns (bool);
                              /// @notice Transfers `amount` tokens from `sender` to `recipient` up to the allowance given to the `msg.sender`
                              /// @param sender The account from which the transfer will be initiated
                              /// @param recipient The recipient of the transfer
                              /// @param amount The amount of the transfer
                              /// @return Returns true for a successful transfer, false for unsuccessful
                              function transferFrom(
                                  address sender,
                                  address recipient,
                                  uint256 amount
                              ) external returns (bool);
                              /// @notice Event emitted when tokens are transferred from one address to another, either via `#transfer` or `#transferFrom`.
                              /// @param from The account from which the tokens were sent, i.e. the balance decreased
                              /// @param to The account to which the tokens were sent, i.e. the balance increased
                              /// @param value The amount of tokens that were transferred
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              /// @notice Event emitted when the approval amount for the spender of a given owner's tokens changes.
                              /// @param owner The account that approved spending of its tokens
                              /// @param spender The account for which the spending allowance was modified
                              /// @param value The new allowance from the owner to the spender
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#mint
                          /// @notice Any contract that calls IUniswapV3PoolActions#mint must implement this interface
                          interface IUniswapV3MintCallback {
                              /// @notice Called to `msg.sender` after minting liquidity to a position from IUniswapV3Pool#mint.
                              /// @dev In the implementation you must pay the pool tokens owed for the minted liquidity.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// @param amount0Owed The amount of token0 due to the pool for the minted liquidity
                              /// @param amount1Owed The amount of token1 due to the pool for the minted liquidity
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#mint call
                              function uniswapV3MintCallback(
                                  uint256 amount0Owed,
                                  uint256 amount1Owed,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#swap
                          /// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
                          interface IUniswapV3SwapCallback {
                              /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
                              /// @dev In the implementation you must pay the pool tokens owed for the swap.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
                              /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
                              /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
                              function uniswapV3SwapCallback(
                                  int256 amount0Delta,
                                  int256 amount1Delta,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#flash
                          /// @notice Any contract that calls IUniswapV3PoolActions#flash must implement this interface
                          interface IUniswapV3FlashCallback {
                              /// @notice Called to `msg.sender` after transferring to the recipient from IUniswapV3Pool#flash.
                              /// @dev In the implementation you must repay the pool the tokens sent by flash plus the computed fee amounts.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// @param fee0 The fee amount in token0 due to the pool by the end of the flash
                              /// @param fee1 The fee amount in token1 due to the pool by the end of the flash
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#flash call
                              function uniswapV3FlashCallback(
                                  uint256 fee0,
                                  uint256 fee1,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that never changes
                          /// @notice These parameters are fixed for a pool forever, i.e., the methods will always return the same values
                          interface IUniswapV3PoolImmutables {
                              /// @notice The contract that deployed the pool, which must adhere to the IUniswapV3Factory interface
                              /// @return The contract address
                              function factory() external view returns (address);
                              /// @notice The first of the two tokens of the pool, sorted by address
                              /// @return The token contract address
                              function token0() external view returns (address);
                              /// @notice The second of the two tokens of the pool, sorted by address
                              /// @return The token contract address
                              function token1() external view returns (address);
                              /// @notice The pool's fee in hundredths of a bip, i.e. 1e-6
                              /// @return The fee
                              function fee() external view returns (uint24);
                              /// @notice The pool tick spacing
                              /// @dev Ticks can only be used at multiples of this value, minimum of 1 and always positive
                              /// e.g.: a tickSpacing of 3 means ticks can be initialized every 3rd tick, i.e., ..., -6, -3, 0, 3, 6, ...
                              /// This value is an int24 to avoid casting even though it is always positive.
                              /// @return The tick spacing
                              function tickSpacing() external view returns (int24);
                              /// @notice The maximum amount of position liquidity that can use any tick in the range
                              /// @dev This parameter is enforced per tick to prevent liquidity from overflowing a uint128 at any point, and
                              /// also prevents out-of-range liquidity from being used to prevent adding in-range liquidity to a pool
                              /// @return The max amount of liquidity per tick
                              function maxLiquidityPerTick() external view returns (uint128);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that can change
                          /// @notice These methods compose the pool's state, and can change with any frequency including multiple times
                          /// per transaction
                          interface IUniswapV3PoolState {
                              /// @notice The 0th storage slot in the pool stores many values, and is exposed as a single method to save gas
                              /// when accessed externally.
                              /// @return sqrtPriceX96 The current price of the pool as a sqrt(token1/token0) Q64.96 value
                              /// tick The current tick of the pool, i.e. according to the last tick transition that was run.
                              /// This value may not always be equal to SqrtTickMath.getTickAtSqrtRatio(sqrtPriceX96) if the price is on a tick
                              /// boundary.
                              /// observationIndex The index of the last oracle observation that was written,
                              /// observationCardinality The current maximum number of observations stored in the pool,
                              /// observationCardinalityNext The next maximum number of observations, to be updated when the observation.
                              /// feeProtocol The protocol fee for both tokens of the pool.
                              /// Encoded as two 4 bit values, where the protocol fee of token1 is shifted 4 bits and the protocol fee of token0
                              /// is the lower 4 bits. Used as the denominator of a fraction of the swap fee, e.g. 4 means 1/4th of the swap fee.
                              /// unlocked Whether the pool is currently locked to reentrancy
                              function slot0()
                                  external
                                  view
                                  returns (
                                      uint160 sqrtPriceX96,
                                      int24 tick,
                                      uint16 observationIndex,
                                      uint16 observationCardinality,
                                      uint16 observationCardinalityNext,
                                      uint8 feeProtocol,
                                      bool unlocked
                                  );
                              /// @notice The fee growth as a Q128.128 fees of token0 collected per unit of liquidity for the entire life of the pool
                              /// @dev This value can overflow the uint256
                              function feeGrowthGlobal0X128() external view returns (uint256);
                              /// @notice The fee growth as a Q128.128 fees of token1 collected per unit of liquidity for the entire life of the pool
                              /// @dev This value can overflow the uint256
                              function feeGrowthGlobal1X128() external view returns (uint256);
                              /// @notice The amounts of token0 and token1 that are owed to the protocol
                              /// @dev Protocol fees will never exceed uint128 max in either token
                              function protocolFees() external view returns (uint128 token0, uint128 token1);
                              /// @notice The currently in range liquidity available to the pool
                              /// @dev This value has no relationship to the total liquidity across all ticks
                              function liquidity() external view returns (uint128);
                              /// @notice Look up information about a specific tick in the pool
                              /// @param tick The tick to look up
                              /// @return liquidityGross the total amount of position liquidity that uses the pool either as tick lower or
                              /// tick upper,
                              /// liquidityNet how much liquidity changes when the pool price crosses the tick,
                              /// feeGrowthOutside0X128 the fee growth on the other side of the tick from the current tick in token0,
                              /// feeGrowthOutside1X128 the fee growth on the other side of the tick from the current tick in token1,
                              /// tickCumulativeOutside the cumulative tick value on the other side of the tick from the current tick
                              /// secondsPerLiquidityOutsideX128 the seconds spent per liquidity on the other side of the tick from the current tick,
                              /// secondsOutside the seconds spent on the other side of the tick from the current tick,
                              /// initialized Set to true if the tick is initialized, i.e. liquidityGross is greater than 0, otherwise equal to false.
                              /// Outside values can only be used if the tick is initialized, i.e. if liquidityGross is greater than 0.
                              /// In addition, these values are only relative and must be used only in comparison to previous snapshots for
                              /// a specific position.
                              function ticks(int24 tick)
                                  external
                                  view
                                  returns (
                                      uint128 liquidityGross,
                                      int128 liquidityNet,
                                      uint256 feeGrowthOutside0X128,
                                      uint256 feeGrowthOutside1X128,
                                      int56 tickCumulativeOutside,
                                      uint160 secondsPerLiquidityOutsideX128,
                                      uint32 secondsOutside,
                                      bool initialized
                                  );
                              /// @notice Returns 256 packed tick initialized boolean values. See TickBitmap for more information
                              function tickBitmap(int16 wordPosition) external view returns (uint256);
                              /// @notice Returns the information about a position by the position's key
                              /// @param key The position's key is a hash of a preimage composed by the owner, tickLower and tickUpper
                              /// @return _liquidity The amount of liquidity in the position,
                              /// Returns feeGrowthInside0LastX128 fee growth of token0 inside the tick range as of the last mint/burn/poke,
                              /// Returns feeGrowthInside1LastX128 fee growth of token1 inside the tick range as of the last mint/burn/poke,
                              /// Returns tokensOwed0 the computed amount of token0 owed to the position as of the last mint/burn/poke,
                              /// Returns tokensOwed1 the computed amount of token1 owed to the position as of the last mint/burn/poke
                              function positions(bytes32 key)
                                  external
                                  view
                                  returns (
                                      uint128 _liquidity,
                                      uint256 feeGrowthInside0LastX128,
                                      uint256 feeGrowthInside1LastX128,
                                      uint128 tokensOwed0,
                                      uint128 tokensOwed1
                                  );
                              /// @notice Returns data about a specific observation index
                              /// @param index The element of the observations array to fetch
                              /// @dev You most likely want to use #observe() instead of this method to get an observation as of some amount of time
                              /// ago, rather than at a specific index in the array.
                              /// @return blockTimestamp The timestamp of the observation,
                              /// Returns tickCumulative the tick multiplied by seconds elapsed for the life of the pool as of the observation timestamp,
                              /// Returns secondsPerLiquidityCumulativeX128 the seconds per in range liquidity for the life of the pool as of the observation timestamp,
                              /// Returns initialized whether the observation has been initialized and the values are safe to use
                              function observations(uint256 index)
                                  external
                                  view
                                  returns (
                                      uint32 blockTimestamp,
                                      int56 tickCumulative,
                                      uint160 secondsPerLiquidityCumulativeX128,
                                      bool initialized
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that is not stored
                          /// @notice Contains view functions to provide information about the pool that is computed rather than stored on the
                          /// blockchain. The functions here may have variable gas costs.
                          interface IUniswapV3PoolDerivedState {
                              /// @notice Returns the cumulative tick and liquidity as of each timestamp `secondsAgo` from the current block timestamp
                              /// @dev To get a time weighted average tick or liquidity-in-range, you must call this with two values, one representing
                              /// the beginning of the period and another for the end of the period. E.g., to get the last hour time-weighted average tick,
                              /// you must call it with secondsAgos = [3600, 0].
                              /// @dev The time weighted average tick represents the geometric time weighted average price of the pool, in
                              /// log base sqrt(1.0001) of token1 / token0. The TickMath library can be used to go from a tick value to a ratio.
                              /// @param secondsAgos From how long ago each cumulative tick and liquidity value should be returned
                              /// @return tickCumulatives Cumulative tick values as of each `secondsAgos` from the current block timestamp
                              /// @return secondsPerLiquidityCumulativeX128s Cumulative seconds per liquidity-in-range value as of each `secondsAgos` from the current block
                              /// timestamp
                              function observe(uint32[] calldata secondsAgos)
                                  external
                                  view
                                  returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s);
                              /// @notice Returns a snapshot of the tick cumulative, seconds per liquidity and seconds inside a tick range
                              /// @dev Snapshots must only be compared to other snapshots, taken over a period for which a position existed.
                              /// I.e., snapshots cannot be compared if a position is not held for the entire period between when the first
                              /// snapshot is taken and the second snapshot is taken.
                              /// @param tickLower The lower tick of the range
                              /// @param tickUpper The upper tick of the range
                              /// @return tickCumulativeInside The snapshot of the tick accumulator for the range
                              /// @return secondsPerLiquidityInsideX128 The snapshot of seconds per liquidity for the range
                              /// @return secondsInside The snapshot of seconds per liquidity for the range
                              function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
                                  external
                                  view
                                  returns (
                                      int56 tickCumulativeInside,
                                      uint160 secondsPerLiquidityInsideX128,
                                      uint32 secondsInside
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Permissionless pool actions
                          /// @notice Contains pool methods that can be called by anyone
                          interface IUniswapV3PoolActions {
                              /// @notice Sets the initial price for the pool
                              /// @dev Price is represented as a sqrt(amountToken1/amountToken0) Q64.96 value
                              /// @param sqrtPriceX96 the initial sqrt price of the pool as a Q64.96
                              function initialize(uint160 sqrtPriceX96) external;
                              /// @notice Adds liquidity for the given recipient/tickLower/tickUpper position
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3MintCallback#uniswapV3MintCallback
                              /// in which they must pay any token0 or token1 owed for the liquidity. The amount of token0/token1 due depends
                              /// on tickLower, tickUpper, the amount of liquidity, and the current price.
                              /// @param recipient The address for which the liquidity will be created
                              /// @param tickLower The lower tick of the position in which to add liquidity
                              /// @param tickUpper The upper tick of the position in which to add liquidity
                              /// @param amount The amount of liquidity to mint
                              /// @param data Any data that should be passed through to the callback
                              /// @return amount0 The amount of token0 that was paid to mint the given amount of liquidity. Matches the value in the callback
                              /// @return amount1 The amount of token1 that was paid to mint the given amount of liquidity. Matches the value in the callback
                              function mint(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount,
                                  bytes calldata data
                              ) external returns (uint256 amount0, uint256 amount1);
                              /// @notice Collects tokens owed to a position
                              /// @dev Does not recompute fees earned, which must be done either via mint or burn of any amount of liquidity.
                              /// Collect must be called by the position owner. To withdraw only token0 or only token1, amount0Requested or
                              /// amount1Requested may be set to zero. To withdraw all tokens owed, caller may pass any value greater than the
                              /// actual tokens owed, e.g. type(uint128).max. Tokens owed may be from accumulated swap fees or burned liquidity.
                              /// @param recipient The address which should receive the fees collected
                              /// @param tickLower The lower tick of the position for which to collect fees
                              /// @param tickUpper The upper tick of the position for which to collect fees
                              /// @param amount0Requested How much token0 should be withdrawn from the fees owed
                              /// @param amount1Requested How much token1 should be withdrawn from the fees owed
                              /// @return amount0 The amount of fees collected in token0
                              /// @return amount1 The amount of fees collected in token1
                              function collect(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external returns (uint128 amount0, uint128 amount1);
                              /// @notice Burn liquidity from the sender and account tokens owed for the liquidity to the position
                              /// @dev Can be used to trigger a recalculation of fees owed to a position by calling with an amount of 0
                              /// @dev Fees must be collected separately via a call to #collect
                              /// @param tickLower The lower tick of the position for which to burn liquidity
                              /// @param tickUpper The upper tick of the position for which to burn liquidity
                              /// @param amount How much liquidity to burn
                              /// @return amount0 The amount of token0 sent to the recipient
                              /// @return amount1 The amount of token1 sent to the recipient
                              function burn(
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount
                              ) external returns (uint256 amount0, uint256 amount1);
                              /// @notice Swap token0 for token1, or token1 for token0
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
                              /// @param recipient The address to receive the output of the swap
                              /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
                              /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
                              /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
                              /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
                              /// @param data Any data to be passed through to the callback
                              /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
                              /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
                              function swap(
                                  address recipient,
                                  bool zeroForOne,
                                  int256 amountSpecified,
                                  uint160 sqrtPriceLimitX96,
                                  bytes calldata data
                              ) external returns (int256 amount0, int256 amount1);
                              /// @notice Receive token0 and/or token1 and pay it back, plus a fee, in the callback
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3FlashCallback#uniswapV3FlashCallback
                              /// @dev Can be used to donate underlying tokens pro-rata to currently in-range liquidity providers by calling
                              /// with 0 amount{0,1} and sending the donation amount(s) from the callback
                              /// @param recipient The address which will receive the token0 and token1 amounts
                              /// @param amount0 The amount of token0 to send
                              /// @param amount1 The amount of token1 to send
                              /// @param data Any data to be passed through to the callback
                              function flash(
                                  address recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  bytes calldata data
                              ) external;
                              /// @notice Increase the maximum number of price and liquidity observations that this pool will store
                              /// @dev This method is no-op if the pool already has an observationCardinalityNext greater than or equal to
                              /// the input observationCardinalityNext.
                              /// @param observationCardinalityNext The desired minimum number of observations for the pool to store
                              function increaseObservationCardinalityNext(uint16 observationCardinalityNext) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Permissioned pool actions
                          /// @notice Contains pool methods that may only be called by the factory owner
                          interface IUniswapV3PoolOwnerActions {
                              /// @notice Set the denominator of the protocol's % share of the fees
                              /// @param feeProtocol0 new protocol fee for token0 of the pool
                              /// @param feeProtocol1 new protocol fee for token1 of the pool
                              function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external;
                              /// @notice Collect the protocol fee accrued to the pool
                              /// @param recipient The address to which collected protocol fees should be sent
                              /// @param amount0Requested The maximum amount of token0 to send, can be 0 to collect fees in only token1
                              /// @param amount1Requested The maximum amount of token1 to send, can be 0 to collect fees in only token0
                              /// @return amount0 The protocol fee collected in token0
                              /// @return amount1 The protocol fee collected in token1
                              function collectProtocol(
                                  address recipient,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external returns (uint128 amount0, uint128 amount1);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Events emitted by a pool
                          /// @notice Contains all events emitted by the pool
                          interface IUniswapV3PoolEvents {
                              /// @notice Emitted exactly once by a pool when #initialize is first called on the pool
                              /// @dev Mint/Burn/Swap cannot be emitted by the pool before Initialize
                              /// @param sqrtPriceX96 The initial sqrt price of the pool, as a Q64.96
                              /// @param tick The initial tick of the pool, i.e. log base 1.0001 of the starting price of the pool
                              event Initialize(uint160 sqrtPriceX96, int24 tick);
                              /// @notice Emitted when liquidity is minted for a given position
                              /// @param sender The address that minted the liquidity
                              /// @param owner The owner of the position and recipient of any minted liquidity
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount The amount of liquidity minted to the position range
                              /// @param amount0 How much token0 was required for the minted liquidity
                              /// @param amount1 How much token1 was required for the minted liquidity
                              event Mint(
                                  address sender,
                                  address indexed owner,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount,
                                  uint256 amount0,
                                  uint256 amount1
                              );
                              /// @notice Emitted when fees are collected by the owner of a position
                              /// @dev Collect events may be emitted with zero amount0 and amount1 when the caller chooses not to collect fees
                              /// @param owner The owner of the position for which fees are collected
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount0 The amount of token0 fees collected
                              /// @param amount1 The amount of token1 fees collected
                              event Collect(
                                  address indexed owner,
                                  address recipient,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount0,
                                  uint128 amount1
                              );
                              /// @notice Emitted when a position's liquidity is removed
                              /// @dev Does not withdraw any fees earned by the liquidity position, which must be withdrawn via #collect
                              /// @param owner The owner of the position for which liquidity is removed
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount The amount of liquidity to remove
                              /// @param amount0 The amount of token0 withdrawn
                              /// @param amount1 The amount of token1 withdrawn
                              event Burn(
                                  address indexed owner,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount,
                                  uint256 amount0,
                                  uint256 amount1
                              );
                              /// @notice Emitted by the pool for any swaps between token0 and token1
                              /// @param sender The address that initiated the swap call, and that received the callback
                              /// @param recipient The address that received the output of the swap
                              /// @param amount0 The delta of the token0 balance of the pool
                              /// @param amount1 The delta of the token1 balance of the pool
                              /// @param sqrtPriceX96 The sqrt(price) of the pool after the swap, as a Q64.96
                              /// @param liquidity The liquidity of the pool after the swap
                              /// @param tick The log base 1.0001 of price of the pool after the swap
                              event Swap(
                                  address indexed sender,
                                  address indexed recipient,
                                  int256 amount0,
                                  int256 amount1,
                                  uint160 sqrtPriceX96,
                                  uint128 liquidity,
                                  int24 tick
                              );
                              /// @notice Emitted by the pool for any flashes of token0/token1
                              /// @param sender The address that initiated the swap call, and that received the callback
                              /// @param recipient The address that received the tokens from flash
                              /// @param amount0 The amount of token0 that was flashed
                              /// @param amount1 The amount of token1 that was flashed
                              /// @param paid0 The amount of token0 paid for the flash, which can exceed the amount0 plus the fee
                              /// @param paid1 The amount of token1 paid for the flash, which can exceed the amount1 plus the fee
                              event Flash(
                                  address indexed sender,
                                  address indexed recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  uint256 paid0,
                                  uint256 paid1
                              );
                              /// @notice Emitted by the pool for increases to the number of observations that can be stored
                              /// @dev observationCardinalityNext is not the observation cardinality until an observation is written at the index
                              /// just before a mint/swap/burn.
                              /// @param observationCardinalityNextOld The previous value of the next observation cardinality
                              /// @param observationCardinalityNextNew The updated value of the next observation cardinality
                              event IncreaseObservationCardinalityNext(
                                  uint16 observationCardinalityNextOld,
                                  uint16 observationCardinalityNextNew
                              );
                              /// @notice Emitted when the protocol fee is changed by the pool
                              /// @param feeProtocol0Old The previous value of the token0 protocol fee
                              /// @param feeProtocol1Old The previous value of the token1 protocol fee
                              /// @param feeProtocol0New The updated value of the token0 protocol fee
                              /// @param feeProtocol1New The updated value of the token1 protocol fee
                              event SetFeeProtocol(uint8 feeProtocol0Old, uint8 feeProtocol1Old, uint8 feeProtocol0New, uint8 feeProtocol1New);
                              /// @notice Emitted when the collected protocol fees are withdrawn by the factory owner
                              /// @param sender The address that collects the protocol fees
                              /// @param recipient The address that receives the collected protocol fees
                              /// @param amount0 The amount of token0 protocol fees that is withdrawn
                              /// @param amount0 The amount of token1 protocol fees that is withdrawn
                              event CollectProtocol(address indexed sender, address indexed recipient, uint128 amount0, uint128 amount1);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title BitMath
                          /// @dev This library provides functionality for computing bit properties of an unsigned integer
                          library BitMath {
                              /// @notice Returns the index of the most significant bit of the number,
                              ///     where the least significant bit is at index 0 and the most significant bit is at index 255
                              /// @dev The function satisfies the property:
                              ///     x >= 2**mostSignificantBit(x) and x < 2**(mostSignificantBit(x)+1)
                              /// @param x the value for which to compute the most significant bit, must be greater than 0
                              /// @return r the index of the most significant bit
                              function mostSignificantBit(uint256 x) internal pure returns (uint8 r) {
                                  require(x > 0);
                                  if (x >= 0x100000000000000000000000000000000) {
                                      x >>= 128;
                                      r += 128;
                                  }
                                  if (x >= 0x10000000000000000) {
                                      x >>= 64;
                                      r += 64;
                                  }
                                  if (x >= 0x100000000) {
                                      x >>= 32;
                                      r += 32;
                                  }
                                  if (x >= 0x10000) {
                                      x >>= 16;
                                      r += 16;
                                  }
                                  if (x >= 0x100) {
                                      x >>= 8;
                                      r += 8;
                                  }
                                  if (x >= 0x10) {
                                      x >>= 4;
                                      r += 4;
                                  }
                                  if (x >= 0x4) {
                                      x >>= 2;
                                      r += 2;
                                  }
                                  if (x >= 0x2) r += 1;
                              }
                              /// @notice Returns the index of the least significant bit of the number,
                              ///     where the least significant bit is at index 0 and the most significant bit is at index 255
                              /// @dev The function satisfies the property:
                              ///     (x & 2**leastSignificantBit(x)) != 0 and (x & (2**(leastSignificantBit(x)) - 1)) == 0)
                              /// @param x the value for which to compute the least significant bit, must be greater than 0
                              /// @return r the index of the least significant bit
                              function leastSignificantBit(uint256 x) internal pure returns (uint8 r) {
                                  require(x > 0);
                                  r = 255;
                                  if (x & type(uint128).max > 0) {
                                      r -= 128;
                                  } else {
                                      x >>= 128;
                                  }
                                  if (x & type(uint64).max > 0) {
                                      r -= 64;
                                  } else {
                                      x >>= 64;
                                  }
                                  if (x & type(uint32).max > 0) {
                                      r -= 32;
                                  } else {
                                      x >>= 32;
                                  }
                                  if (x & type(uint16).max > 0) {
                                      r -= 16;
                                  } else {
                                      x >>= 16;
                                  }
                                  if (x & type(uint8).max > 0) {
                                      r -= 8;
                                  } else {
                                      x >>= 8;
                                  }
                                  if (x & 0xf > 0) {
                                      r -= 4;
                                  } else {
                                      x >>= 4;
                                  }
                                  if (x & 0x3 > 0) {
                                      r -= 2;
                                  } else {
                                      x >>= 2;
                                  }
                                  if (x & 0x1 > 0) r -= 1;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math functions that do not check inputs or outputs
                          /// @notice Contains methods that perform common math functions but do not do any overflow or underflow checks
                          library UnsafeMath {
                              /// @notice Returns ceil(x / y)
                              /// @dev division by 0 has unspecified behavior, and must be checked externally
                              /// @param x The dividend
                              /// @param y The divisor
                              /// @return z The quotient, ceil(x / y)
                              function divRoundingUp(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  assembly {
                                      z := add(div(x, y), gt(mod(x, y), 0))
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.4.0;
                          /// @title FixedPoint96
                          /// @notice A library for handling binary fixed point numbers, see https://en.wikipedia.org/wiki/Q_(number_format)
                          /// @dev Used in SqrtPriceMath.sol
                          library FixedPoint96 {
                              uint8 internal constant RESOLUTION = 96;
                              uint256 internal constant Q96 = 0x1000000000000000000000000;
                          }
                          

                          File 5 of 13: SwapRouter
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          pragma abicoder v2;
                          import '@uniswap/v3-core/contracts/libraries/SafeCast.sol';
                          import '@uniswap/v3-core/contracts/libraries/TickMath.sol';
                          import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
                          import './interfaces/ISwapRouter.sol';
                          import './base/PeripheryImmutableState.sol';
                          import './base/PeripheryValidation.sol';
                          import './base/PeripheryPaymentsWithFee.sol';
                          import './base/Multicall.sol';
                          import './base/SelfPermit.sol';
                          import './libraries/Path.sol';
                          import './libraries/PoolAddress.sol';
                          import './libraries/CallbackValidation.sol';
                          import './interfaces/external/IWETH9.sol';
                          /// @title Uniswap V3 Swap Router
                          /// @notice Router for stateless execution of swaps against Uniswap V3
                          contract SwapRouter is
                              ISwapRouter,
                              PeripheryImmutableState,
                              PeripheryValidation,
                              PeripheryPaymentsWithFee,
                              Multicall,
                              SelfPermit
                          {
                              using Path for bytes;
                              using SafeCast for uint256;
                              /// @dev Used as the placeholder value for amountInCached, because the computed amount in for an exact output swap
                              /// can never actually be this value
                              uint256 private constant DEFAULT_AMOUNT_IN_CACHED = type(uint256).max;
                              /// @dev Transient storage variable used for returning the computed amount in for an exact output swap.
                              uint256 private amountInCached = DEFAULT_AMOUNT_IN_CACHED;
                              constructor(address _factory, address _WETH9) PeripheryImmutableState(_factory, _WETH9) {}
                              /// @dev Returns the pool for the given token pair and fee. The pool contract may or may not exist.
                              function getPool(
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) private view returns (IUniswapV3Pool) {
                                  return IUniswapV3Pool(PoolAddress.computeAddress(factory, PoolAddress.getPoolKey(tokenA, tokenB, fee)));
                              }
                              struct SwapCallbackData {
                                  bytes path;
                                  address payer;
                              }
                              /// @inheritdoc IUniswapV3SwapCallback
                              function uniswapV3SwapCallback(
                                  int256 amount0Delta,
                                  int256 amount1Delta,
                                  bytes calldata _data
                              ) external override {
                                  require(amount0Delta > 0 || amount1Delta > 0); // swaps entirely within 0-liquidity regions are not supported
                                  SwapCallbackData memory data = abi.decode(_data, (SwapCallbackData));
                                  (address tokenIn, address tokenOut, uint24 fee) = data.path.decodeFirstPool();
                                  CallbackValidation.verifyCallback(factory, tokenIn, tokenOut, fee);
                                  (bool isExactInput, uint256 amountToPay) =
                                      amount0Delta > 0
                                          ? (tokenIn < tokenOut, uint256(amount0Delta))
                                          : (tokenOut < tokenIn, uint256(amount1Delta));
                                  if (isExactInput) {
                                      pay(tokenIn, data.payer, msg.sender, amountToPay);
                                  } else {
                                      // either initiate the next swap or pay
                                      if (data.path.hasMultiplePools()) {
                                          data.path = data.path.skipToken();
                                          exactOutputInternal(amountToPay, msg.sender, 0, data);
                                      } else {
                                          amountInCached = amountToPay;
                                          tokenIn = tokenOut; // swap in/out because exact output swaps are reversed
                                          pay(tokenIn, data.payer, msg.sender, amountToPay);
                                      }
                                  }
                              }
                              /// @dev Performs a single exact input swap
                              function exactInputInternal(
                                  uint256 amountIn,
                                  address recipient,
                                  uint160 sqrtPriceLimitX96,
                                  SwapCallbackData memory data
                              ) private returns (uint256 amountOut) {
                                  // allow swapping to the router address with address 0
                                  if (recipient == address(0)) recipient = address(this);
                                  (address tokenIn, address tokenOut, uint24 fee) = data.path.decodeFirstPool();
                                  bool zeroForOne = tokenIn < tokenOut;
                                  (int256 amount0, int256 amount1) =
                                      getPool(tokenIn, tokenOut, fee).swap(
                                          recipient,
                                          zeroForOne,
                                          amountIn.toInt256(),
                                          sqrtPriceLimitX96 == 0
                                              ? (zeroForOne ? TickMath.MIN_SQRT_RATIO + 1 : TickMath.MAX_SQRT_RATIO - 1)
                                              : sqrtPriceLimitX96,
                                          abi.encode(data)
                                      );
                                  return uint256(-(zeroForOne ? amount1 : amount0));
                              }
                              /// @inheritdoc ISwapRouter
                              function exactInputSingle(ExactInputSingleParams calldata params)
                                  external
                                  payable
                                  override
                                  checkDeadline(params.deadline)
                                  returns (uint256 amountOut)
                              {
                                  amountOut = exactInputInternal(
                                      params.amountIn,
                                      params.recipient,
                                      params.sqrtPriceLimitX96,
                                      SwapCallbackData({path: abi.encodePacked(params.tokenIn, params.fee, params.tokenOut), payer: msg.sender})
                                  );
                                  require(amountOut >= params.amountOutMinimum, 'Too little received');
                              }
                              /// @inheritdoc ISwapRouter
                              function exactInput(ExactInputParams memory params)
                                  external
                                  payable
                                  override
                                  checkDeadline(params.deadline)
                                  returns (uint256 amountOut)
                              {
                                  address payer = msg.sender; // msg.sender pays for the first hop
                                  while (true) {
                                      bool hasMultiplePools = params.path.hasMultiplePools();
                                      // the outputs of prior swaps become the inputs to subsequent ones
                                      params.amountIn = exactInputInternal(
                                          params.amountIn,
                                          hasMultiplePools ? address(this) : params.recipient, // for intermediate swaps, this contract custodies
                                          0,
                                          SwapCallbackData({
                                              path: params.path.getFirstPool(), // only the first pool in the path is necessary
                                              payer: payer
                                          })
                                      );
                                      // decide whether to continue or terminate
                                      if (hasMultiplePools) {
                                          payer = address(this); // at this point, the caller has paid
                                          params.path = params.path.skipToken();
                                      } else {
                                          amountOut = params.amountIn;
                                          break;
                                      }
                                  }
                                  require(amountOut >= params.amountOutMinimum, 'Too little received');
                              }
                              /// @dev Performs a single exact output swap
                              function exactOutputInternal(
                                  uint256 amountOut,
                                  address recipient,
                                  uint160 sqrtPriceLimitX96,
                                  SwapCallbackData memory data
                              ) private returns (uint256 amountIn) {
                                  // allow swapping to the router address with address 0
                                  if (recipient == address(0)) recipient = address(this);
                                  (address tokenOut, address tokenIn, uint24 fee) = data.path.decodeFirstPool();
                                  bool zeroForOne = tokenIn < tokenOut;
                                  (int256 amount0Delta, int256 amount1Delta) =
                                      getPool(tokenIn, tokenOut, fee).swap(
                                          recipient,
                                          zeroForOne,
                                          -amountOut.toInt256(),
                                          sqrtPriceLimitX96 == 0
                                              ? (zeroForOne ? TickMath.MIN_SQRT_RATIO + 1 : TickMath.MAX_SQRT_RATIO - 1)
                                              : sqrtPriceLimitX96,
                                          abi.encode(data)
                                      );
                                  uint256 amountOutReceived;
                                  (amountIn, amountOutReceived) = zeroForOne
                                      ? (uint256(amount0Delta), uint256(-amount1Delta))
                                      : (uint256(amount1Delta), uint256(-amount0Delta));
                                  // it's technically possible to not receive the full output amount,
                                  // so if no price limit has been specified, require this possibility away
                                  if (sqrtPriceLimitX96 == 0) require(amountOutReceived == amountOut);
                              }
                              /// @inheritdoc ISwapRouter
                              function exactOutputSingle(ExactOutputSingleParams calldata params)
                                  external
                                  payable
                                  override
                                  checkDeadline(params.deadline)
                                  returns (uint256 amountIn)
                              {
                                  // avoid an SLOAD by using the swap return data
                                  amountIn = exactOutputInternal(
                                      params.amountOut,
                                      params.recipient,
                                      params.sqrtPriceLimitX96,
                                      SwapCallbackData({path: abi.encodePacked(params.tokenOut, params.fee, params.tokenIn), payer: msg.sender})
                                  );
                                  require(amountIn <= params.amountInMaximum, 'Too much requested');
                                  // has to be reset even though we don't use it in the single hop case
                                  amountInCached = DEFAULT_AMOUNT_IN_CACHED;
                              }
                              /// @inheritdoc ISwapRouter
                              function exactOutput(ExactOutputParams calldata params)
                                  external
                                  payable
                                  override
                                  checkDeadline(params.deadline)
                                  returns (uint256 amountIn)
                              {
                                  // it's okay that the payer is fixed to msg.sender here, as they're only paying for the "final" exact output
                                  // swap, which happens first, and subsequent swaps are paid for within nested callback frames
                                  exactOutputInternal(
                                      params.amountOut,
                                      params.recipient,
                                      0,
                                      SwapCallbackData({path: params.path, payer: msg.sender})
                                  );
                                  amountIn = amountInCached;
                                  require(amountIn <= params.amountInMaximum, 'Too much requested');
                                  amountInCached = DEFAULT_AMOUNT_IN_CACHED;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Safe casting methods
                          /// @notice Contains methods for safely casting between types
                          library SafeCast {
                              /// @notice Cast a uint256 to a uint160, revert on overflow
                              /// @param y The uint256 to be downcasted
                              /// @return z The downcasted integer, now type uint160
                              function toUint160(uint256 y) internal pure returns (uint160 z) {
                                  require((z = uint160(y)) == y);
                              }
                              /// @notice Cast a int256 to a int128, revert on overflow or underflow
                              /// @param y The int256 to be downcasted
                              /// @return z The downcasted integer, now type int128
                              function toInt128(int256 y) internal pure returns (int128 z) {
                                  require((z = int128(y)) == y);
                              }
                              /// @notice Cast a uint256 to a int256, revert on overflow
                              /// @param y The uint256 to be casted
                              /// @return z The casted integer, now type int256
                              function toInt256(uint256 y) internal pure returns (int256 z) {
                                  require(y < 2**255);
                                  z = int256(y);
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math library for computing sqrt prices from ticks and vice versa
                          /// @notice Computes sqrt price for ticks of size 1.0001, i.e. sqrt(1.0001^tick) as fixed point Q64.96 numbers. Supports
                          /// prices between 2**-128 and 2**128
                          library TickMath {
                              /// @dev The minimum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**-128
                              int24 internal constant MIN_TICK = -887272;
                              /// @dev The maximum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**128
                              int24 internal constant MAX_TICK = -MIN_TICK;
                              /// @dev The minimum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MIN_TICK)
                              uint160 internal constant MIN_SQRT_RATIO = 4295128739;
                              /// @dev The maximum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MAX_TICK)
                              uint160 internal constant MAX_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
                              /// @notice Calculates sqrt(1.0001^tick) * 2^96
                              /// @dev Throws if |tick| > max tick
                              /// @param tick The input tick for the above formula
                              /// @return sqrtPriceX96 A Fixed point Q64.96 number representing the sqrt of the ratio of the two assets (token1/token0)
                              /// at the given tick
                              function getSqrtRatioAtTick(int24 tick) internal pure returns (uint160 sqrtPriceX96) {
                                  uint256 absTick = tick < 0 ? uint256(-int256(tick)) : uint256(int256(tick));
                                  require(absTick <= uint256(MAX_TICK), 'T');
                                  uint256 ratio = absTick & 0x1 != 0 ? 0xfffcb933bd6fad37aa2d162d1a594001 : 0x100000000000000000000000000000000;
                                  if (absTick & 0x2 != 0) ratio = (ratio * 0xfff97272373d413259a46990580e213a) >> 128;
                                  if (absTick & 0x4 != 0) ratio = (ratio * 0xfff2e50f5f656932ef12357cf3c7fdcc) >> 128;
                                  if (absTick & 0x8 != 0) ratio = (ratio * 0xffe5caca7e10e4e61c3624eaa0941cd0) >> 128;
                                  if (absTick & 0x10 != 0) ratio = (ratio * 0xffcb9843d60f6159c9db58835c926644) >> 128;
                                  if (absTick & 0x20 != 0) ratio = (ratio * 0xff973b41fa98c081472e6896dfb254c0) >> 128;
                                  if (absTick & 0x40 != 0) ratio = (ratio * 0xff2ea16466c96a3843ec78b326b52861) >> 128;
                                  if (absTick & 0x80 != 0) ratio = (ratio * 0xfe5dee046a99a2a811c461f1969c3053) >> 128;
                                  if (absTick & 0x100 != 0) ratio = (ratio * 0xfcbe86c7900a88aedcffc83b479aa3a4) >> 128;
                                  if (absTick & 0x200 != 0) ratio = (ratio * 0xf987a7253ac413176f2b074cf7815e54) >> 128;
                                  if (absTick & 0x400 != 0) ratio = (ratio * 0xf3392b0822b70005940c7a398e4b70f3) >> 128;
                                  if (absTick & 0x800 != 0) ratio = (ratio * 0xe7159475a2c29b7443b29c7fa6e889d9) >> 128;
                                  if (absTick & 0x1000 != 0) ratio = (ratio * 0xd097f3bdfd2022b8845ad8f792aa5825) >> 128;
                                  if (absTick & 0x2000 != 0) ratio = (ratio * 0xa9f746462d870fdf8a65dc1f90e061e5) >> 128;
                                  if (absTick & 0x4000 != 0) ratio = (ratio * 0x70d869a156d2a1b890bb3df62baf32f7) >> 128;
                                  if (absTick & 0x8000 != 0) ratio = (ratio * 0x31be135f97d08fd981231505542fcfa6) >> 128;
                                  if (absTick & 0x10000 != 0) ratio = (ratio * 0x9aa508b5b7a84e1c677de54f3e99bc9) >> 128;
                                  if (absTick & 0x20000 != 0) ratio = (ratio * 0x5d6af8dedb81196699c329225ee604) >> 128;
                                  if (absTick & 0x40000 != 0) ratio = (ratio * 0x2216e584f5fa1ea926041bedfe98) >> 128;
                                  if (absTick & 0x80000 != 0) ratio = (ratio * 0x48a170391f7dc42444e8fa2) >> 128;
                                  if (tick > 0) ratio = type(uint256).max / ratio;
                                  // this divides by 1<<32 rounding up to go from a Q128.128 to a Q128.96.
                                  // we then downcast because we know the result always fits within 160 bits due to our tick input constraint
                                  // we round up in the division so getTickAtSqrtRatio of the output price is always consistent
                                  sqrtPriceX96 = uint160((ratio >> 32) + (ratio % (1 << 32) == 0 ? 0 : 1));
                              }
                              /// @notice Calculates the greatest tick value such that getRatioAtTick(tick) <= ratio
                              /// @dev Throws in case sqrtPriceX96 < MIN_SQRT_RATIO, as MIN_SQRT_RATIO is the lowest value getRatioAtTick may
                              /// ever return.
                              /// @param sqrtPriceX96 The sqrt ratio for which to compute the tick as a Q64.96
                              /// @return tick The greatest tick for which the ratio is less than or equal to the input ratio
                              function getTickAtSqrtRatio(uint160 sqrtPriceX96) internal pure returns (int24 tick) {
                                  // second inequality must be < because the price can never reach the price at the max tick
                                  require(sqrtPriceX96 >= MIN_SQRT_RATIO && sqrtPriceX96 < MAX_SQRT_RATIO, 'R');
                                  uint256 ratio = uint256(sqrtPriceX96) << 32;
                                  uint256 r = ratio;
                                  uint256 msb = 0;
                                  assembly {
                                      let f := shl(7, gt(r, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(6, gt(r, 0xFFFFFFFFFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(5, gt(r, 0xFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(4, gt(r, 0xFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(3, gt(r, 0xFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(2, gt(r, 0xF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(1, gt(r, 0x3))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := gt(r, 0x1)
                                      msb := or(msb, f)
                                  }
                                  if (msb >= 128) r = ratio >> (msb - 127);
                                  else r = ratio << (127 - msb);
                                  int256 log_2 = (int256(msb) - 128) << 64;
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(63, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(62, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(61, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(60, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(59, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(58, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(57, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(56, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(55, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(54, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(53, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(52, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(51, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(50, f))
                                  }
                                  int256 log_sqrt10001 = log_2 * 255738958999603826347141; // 128.128 number
                                  int24 tickLow = int24((log_sqrt10001 - 3402992956809132418596140100660247210) >> 128);
                                  int24 tickHi = int24((log_sqrt10001 + 291339464771989622907027621153398088495) >> 128);
                                  tick = tickLow == tickHi ? tickLow : getSqrtRatioAtTick(tickHi) <= sqrtPriceX96 ? tickHi : tickLow;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          import './pool/IUniswapV3PoolImmutables.sol';
                          import './pool/IUniswapV3PoolState.sol';
                          import './pool/IUniswapV3PoolDerivedState.sol';
                          import './pool/IUniswapV3PoolActions.sol';
                          import './pool/IUniswapV3PoolOwnerActions.sol';
                          import './pool/IUniswapV3PoolEvents.sol';
                          /// @title The interface for a Uniswap V3 Pool
                          /// @notice A Uniswap pool facilitates swapping and automated market making between any two assets that strictly conform
                          /// to the ERC20 specification
                          /// @dev The pool interface is broken up into many smaller pieces
                          interface IUniswapV3Pool is
                              IUniswapV3PoolImmutables,
                              IUniswapV3PoolState,
                              IUniswapV3PoolDerivedState,
                              IUniswapV3PoolActions,
                              IUniswapV3PoolOwnerActions,
                              IUniswapV3PoolEvents
                          {
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          pragma abicoder v2;
                          import '@uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol';
                          /// @title Router token swapping functionality
                          /// @notice Functions for swapping tokens via Uniswap V3
                          interface ISwapRouter is IUniswapV3SwapCallback {
                              struct ExactInputSingleParams {
                                  address tokenIn;
                                  address tokenOut;
                                  uint24 fee;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountIn;
                                  uint256 amountOutMinimum;
                                  uint160 sqrtPriceLimitX96;
                              }
                              /// @notice Swaps `amountIn` of one token for as much as possible of another token
                              /// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
                              /// @return amountOut The amount of the received token
                              function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);
                              struct ExactInputParams {
                                  bytes path;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountIn;
                                  uint256 amountOutMinimum;
                              }
                              /// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
                              /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
                              /// @return amountOut The amount of the received token
                              function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);
                              struct ExactOutputSingleParams {
                                  address tokenIn;
                                  address tokenOut;
                                  uint24 fee;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountOut;
                                  uint256 amountInMaximum;
                                  uint160 sqrtPriceLimitX96;
                              }
                              /// @notice Swaps as little as possible of one token for `amountOut` of another token
                              /// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
                              /// @return amountIn The amount of the input token
                              function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);
                              struct ExactOutputParams {
                                  bytes path;
                                  address recipient;
                                  uint256 deadline;
                                  uint256 amountOut;
                                  uint256 amountInMaximum;
                              }
                              /// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
                              /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
                              /// @return amountIn The amount of the input token
                              function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          import '../interfaces/IPeripheryImmutableState.sol';
                          /// @title Immutable state
                          /// @notice Immutable state used by periphery contracts
                          abstract contract PeripheryImmutableState is IPeripheryImmutableState {
                              /// @inheritdoc IPeripheryImmutableState
                              address public immutable override factory;
                              /// @inheritdoc IPeripheryImmutableState
                              address public immutable override WETH9;
                              constructor(address _factory, address _WETH9) {
                                  factory = _factory;
                                  WETH9 = _WETH9;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          import './BlockTimestamp.sol';
                          abstract contract PeripheryValidation is BlockTimestamp {
                              modifier checkDeadline(uint256 deadline) {
                                  require(_blockTimestamp() <= deadline, 'Transaction too old');
                                  _;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
                          import '@uniswap/v3-core/contracts/libraries/LowGasSafeMath.sol';
                          import './PeripheryPayments.sol';
                          import '../interfaces/IPeripheryPaymentsWithFee.sol';
                          import '../interfaces/external/IWETH9.sol';
                          import '../libraries/TransferHelper.sol';
                          abstract contract PeripheryPaymentsWithFee is PeripheryPayments, IPeripheryPaymentsWithFee {
                              using LowGasSafeMath for uint256;
                              /// @inheritdoc IPeripheryPaymentsWithFee
                              function unwrapWETH9WithFee(
                                  uint256 amountMinimum,
                                  address recipient,
                                  uint256 feeBips,
                                  address feeRecipient
                              ) public payable override {
                                  require(feeBips > 0 && feeBips <= 100);
                                  uint256 balanceWETH9 = IWETH9(WETH9).balanceOf(address(this));
                                  require(balanceWETH9 >= amountMinimum, 'Insufficient WETH9');
                                  if (balanceWETH9 > 0) {
                                      IWETH9(WETH9).withdraw(balanceWETH9);
                                      uint256 feeAmount = balanceWETH9.mul(feeBips) / 10_000;
                                      if (feeAmount > 0) TransferHelper.safeTransferETH(feeRecipient, feeAmount);
                                      TransferHelper.safeTransferETH(recipient, balanceWETH9 - feeAmount);
                                  }
                              }
                              /// @inheritdoc IPeripheryPaymentsWithFee
                              function sweepTokenWithFee(
                                  address token,
                                  uint256 amountMinimum,
                                  address recipient,
                                  uint256 feeBips,
                                  address feeRecipient
                              ) public payable override {
                                  require(feeBips > 0 && feeBips <= 100);
                                  uint256 balanceToken = IERC20(token).balanceOf(address(this));
                                  require(balanceToken >= amountMinimum, 'Insufficient token');
                                  if (balanceToken > 0) {
                                      uint256 feeAmount = balanceToken.mul(feeBips) / 10_000;
                                      if (feeAmount > 0) TransferHelper.safeTransfer(token, feeRecipient, feeAmount);
                                      TransferHelper.safeTransfer(token, recipient, balanceToken - feeAmount);
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          pragma abicoder v2;
                          import '../interfaces/IMulticall.sol';
                          /// @title Multicall
                          /// @notice Enables calling multiple methods in a single call to the contract
                          abstract contract Multicall is IMulticall {
                              /// @inheritdoc IMulticall
                              function multicall(bytes[] calldata data) external payable override returns (bytes[] memory results) {
                                  results = new bytes[](data.length);
                                  for (uint256 i = 0; i < data.length; i++) {
                                      (bool success, bytes memory result) = address(this).delegatecall(data[i]);
                                      if (!success) {
                                          // Next 5 lines from https://ethereum.stackexchange.com/a/83577
                                          if (result.length < 68) revert();
                                          assembly {
                                              result := add(result, 0x04)
                                          }
                                          revert(abi.decode(result, (string)));
                                      }
                                      results[i] = result;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
                          import '@openzeppelin/contracts/drafts/IERC20Permit.sol';
                          import '../interfaces/ISelfPermit.sol';
                          import '../interfaces/external/IERC20PermitAllowed.sol';
                          /// @title Self Permit
                          /// @notice Functionality to call permit on any EIP-2612-compliant token for use in the route
                          /// @dev These functions are expected to be embedded in multicalls to allow EOAs to approve a contract and call a function
                          /// that requires an approval in a single transaction.
                          abstract contract SelfPermit is ISelfPermit {
                              /// @inheritdoc ISelfPermit
                              function selfPermit(
                                  address token,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) public payable override {
                                  IERC20Permit(token).permit(msg.sender, address(this), value, deadline, v, r, s);
                              }
                              /// @inheritdoc ISelfPermit
                              function selfPermitIfNecessary(
                                  address token,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external payable override {
                                  if (IERC20(token).allowance(msg.sender, address(this)) < value) selfPermit(token, value, deadline, v, r, s);
                              }
                              /// @inheritdoc ISelfPermit
                              function selfPermitAllowed(
                                  address token,
                                  uint256 nonce,
                                  uint256 expiry,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) public payable override {
                                  IERC20PermitAllowed(token).permit(msg.sender, address(this), nonce, expiry, true, v, r, s);
                              }
                              /// @inheritdoc ISelfPermit
                              function selfPermitAllowedIfNecessary(
                                  address token,
                                  uint256 nonce,
                                  uint256 expiry,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external payable override {
                                  if (IERC20(token).allowance(msg.sender, address(this)) < type(uint256).max)
                                      selfPermitAllowed(token, nonce, expiry, v, r, s);
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.6.0;
                          import './BytesLib.sol';
                          /// @title Functions for manipulating path data for multihop swaps
                          library Path {
                              using BytesLib for bytes;
                              /// @dev The length of the bytes encoded address
                              uint256 private constant ADDR_SIZE = 20;
                              /// @dev The length of the bytes encoded fee
                              uint256 private constant FEE_SIZE = 3;
                              /// @dev The offset of a single token address and pool fee
                              uint256 private constant NEXT_OFFSET = ADDR_SIZE + FEE_SIZE;
                              /// @dev The offset of an encoded pool key
                              uint256 private constant POP_OFFSET = NEXT_OFFSET + ADDR_SIZE;
                              /// @dev The minimum length of an encoding that contains 2 or more pools
                              uint256 private constant MULTIPLE_POOLS_MIN_LENGTH = POP_OFFSET + NEXT_OFFSET;
                              /// @notice Returns true iff the path contains two or more pools
                              /// @param path The encoded swap path
                              /// @return True if path contains two or more pools, otherwise false
                              function hasMultiplePools(bytes memory path) internal pure returns (bool) {
                                  return path.length >= MULTIPLE_POOLS_MIN_LENGTH;
                              }
                              /// @notice Decodes the first pool in path
                              /// @param path The bytes encoded swap path
                              /// @return tokenA The first token of the given pool
                              /// @return tokenB The second token of the given pool
                              /// @return fee The fee level of the pool
                              function decodeFirstPool(bytes memory path)
                                  internal
                                  pure
                                  returns (
                                      address tokenA,
                                      address tokenB,
                                      uint24 fee
                                  )
                              {
                                  tokenA = path.toAddress(0);
                                  fee = path.toUint24(ADDR_SIZE);
                                  tokenB = path.toAddress(NEXT_OFFSET);
                              }
                              /// @notice Gets the segment corresponding to the first pool in the path
                              /// @param path The bytes encoded swap path
                              /// @return The segment containing all data necessary to target the first pool in the path
                              function getFirstPool(bytes memory path) internal pure returns (bytes memory) {
                                  return path.slice(0, POP_OFFSET);
                              }
                              /// @notice Skips a token + fee element from the buffer and returns the remainder
                              /// @param path The swap path
                              /// @return The remaining token + fee elements in the path
                              function skipToken(bytes memory path) internal pure returns (bytes memory) {
                                  return path.slice(NEXT_OFFSET, path.length - NEXT_OFFSET);
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Provides functions for deriving a pool address from the factory, tokens, and the fee
                          library PoolAddress {
                              bytes32 internal constant POOL_INIT_CODE_HASH = 0xe34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54;
                              /// @notice The identifying key of the pool
                              struct PoolKey {
                                  address token0;
                                  address token1;
                                  uint24 fee;
                              }
                              /// @notice Returns PoolKey: the ordered tokens with the matched fee levels
                              /// @param tokenA The first token of a pool, unsorted
                              /// @param tokenB The second token of a pool, unsorted
                              /// @param fee The fee level of the pool
                              /// @return Poolkey The pool details with ordered token0 and token1 assignments
                              function getPoolKey(
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) internal pure returns (PoolKey memory) {
                                  if (tokenA > tokenB) (tokenA, tokenB) = (tokenB, tokenA);
                                  return PoolKey({token0: tokenA, token1: tokenB, fee: fee});
                              }
                              /// @notice Deterministically computes the pool address given the factory and PoolKey
                              /// @param factory The Uniswap V3 factory contract address
                              /// @param key The PoolKey
                              /// @return pool The contract address of the V3 pool
                              function computeAddress(address factory, PoolKey memory key) internal pure returns (address pool) {
                                  require(key.token0 < key.token1);
                                  pool = address(
                                      uint256(
                                          keccak256(
                                              abi.encodePacked(
                                                  hex'ff',
                                                  factory,
                                                  keccak256(abi.encode(key.token0, key.token1, key.fee)),
                                                  POOL_INIT_CODE_HASH
                                              )
                                          )
                                      )
                                  );
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
                          import './PoolAddress.sol';
                          /// @notice Provides validation for callbacks from Uniswap V3 Pools
                          library CallbackValidation {
                              /// @notice Returns the address of a valid Uniswap V3 Pool
                              /// @param factory The contract address of the Uniswap V3 factory
                              /// @param tokenA The contract address of either token0 or token1
                              /// @param tokenB The contract address of the other token
                              /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// @return pool The V3 pool contract address
                              function verifyCallback(
                                  address factory,
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) internal view returns (IUniswapV3Pool pool) {
                                  return verifyCallback(factory, PoolAddress.getPoolKey(tokenA, tokenB, fee));
                              }
                              /// @notice Returns the address of a valid Uniswap V3 Pool
                              /// @param factory The contract address of the Uniswap V3 factory
                              /// @param poolKey The identifying key of the V3 pool
                              /// @return pool The V3 pool contract address
                              function verifyCallback(address factory, PoolAddress.PoolKey memory poolKey)
                                  internal
                                  view
                                  returns (IUniswapV3Pool pool)
                              {
                                  pool = IUniswapV3Pool(PoolAddress.computeAddress(factory, poolKey));
                                  require(msg.sender == address(pool));
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
                          /// @title Interface for WETH9
                          interface IWETH9 is IERC20 {
                              /// @notice Deposit ether to get wrapped ether
                              function deposit() external payable;
                              /// @notice Withdraw wrapped ether to get ether
                              function withdraw(uint256) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that never changes
                          /// @notice These parameters are fixed for a pool forever, i.e., the methods will always return the same values
                          interface IUniswapV3PoolImmutables {
                              /// @notice The contract that deployed the pool, which must adhere to the IUniswapV3Factory interface
                              /// @return The contract address
                              function factory() external view returns (address);
                              /// @notice The first of the two tokens of the pool, sorted by address
                              /// @return The token contract address
                              function token0() external view returns (address);
                              /// @notice The second of the two tokens of the pool, sorted by address
                              /// @return The token contract address
                              function token1() external view returns (address);
                              /// @notice The pool's fee in hundredths of a bip, i.e. 1e-6
                              /// @return The fee
                              function fee() external view returns (uint24);
                              /// @notice The pool tick spacing
                              /// @dev Ticks can only be used at multiples of this value, minimum of 1 and always positive
                              /// e.g.: a tickSpacing of 3 means ticks can be initialized every 3rd tick, i.e., ..., -6, -3, 0, 3, 6, ...
                              /// This value is an int24 to avoid casting even though it is always positive.
                              /// @return The tick spacing
                              function tickSpacing() external view returns (int24);
                              /// @notice The maximum amount of position liquidity that can use any tick in the range
                              /// @dev This parameter is enforced per tick to prevent liquidity from overflowing a uint128 at any point, and
                              /// also prevents out-of-range liquidity from being used to prevent adding in-range liquidity to a pool
                              /// @return The max amount of liquidity per tick
                              function maxLiquidityPerTick() external view returns (uint128);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that can change
                          /// @notice These methods compose the pool's state, and can change with any frequency including multiple times
                          /// per transaction
                          interface IUniswapV3PoolState {
                              /// @notice The 0th storage slot in the pool stores many values, and is exposed as a single method to save gas
                              /// when accessed externally.
                              /// @return sqrtPriceX96 The current price of the pool as a sqrt(token1/token0) Q64.96 value
                              /// tick The current tick of the pool, i.e. according to the last tick transition that was run.
                              /// This value may not always be equal to SqrtTickMath.getTickAtSqrtRatio(sqrtPriceX96) if the price is on a tick
                              /// boundary.
                              /// observationIndex The index of the last oracle observation that was written,
                              /// observationCardinality The current maximum number of observations stored in the pool,
                              /// observationCardinalityNext The next maximum number of observations, to be updated when the observation.
                              /// feeProtocol The protocol fee for both tokens of the pool.
                              /// Encoded as two 4 bit values, where the protocol fee of token1 is shifted 4 bits and the protocol fee of token0
                              /// is the lower 4 bits. Used as the denominator of a fraction of the swap fee, e.g. 4 means 1/4th of the swap fee.
                              /// unlocked Whether the pool is currently locked to reentrancy
                              function slot0()
                                  external
                                  view
                                  returns (
                                      uint160 sqrtPriceX96,
                                      int24 tick,
                                      uint16 observationIndex,
                                      uint16 observationCardinality,
                                      uint16 observationCardinalityNext,
                                      uint8 feeProtocol,
                                      bool unlocked
                                  );
                              /// @notice The fee growth as a Q128.128 fees of token0 collected per unit of liquidity for the entire life of the pool
                              /// @dev This value can overflow the uint256
                              function feeGrowthGlobal0X128() external view returns (uint256);
                              /// @notice The fee growth as a Q128.128 fees of token1 collected per unit of liquidity for the entire life of the pool
                              /// @dev This value can overflow the uint256
                              function feeGrowthGlobal1X128() external view returns (uint256);
                              /// @notice The amounts of token0 and token1 that are owed to the protocol
                              /// @dev Protocol fees will never exceed uint128 max in either token
                              function protocolFees() external view returns (uint128 token0, uint128 token1);
                              /// @notice The currently in range liquidity available to the pool
                              /// @dev This value has no relationship to the total liquidity across all ticks
                              function liquidity() external view returns (uint128);
                              /// @notice Look up information about a specific tick in the pool
                              /// @param tick The tick to look up
                              /// @return liquidityGross the total amount of position liquidity that uses the pool either as tick lower or
                              /// tick upper,
                              /// liquidityNet how much liquidity changes when the pool price crosses the tick,
                              /// feeGrowthOutside0X128 the fee growth on the other side of the tick from the current tick in token0,
                              /// feeGrowthOutside1X128 the fee growth on the other side of the tick from the current tick in token1,
                              /// tickCumulativeOutside the cumulative tick value on the other side of the tick from the current tick
                              /// secondsPerLiquidityOutsideX128 the seconds spent per liquidity on the other side of the tick from the current tick,
                              /// secondsOutside the seconds spent on the other side of the tick from the current tick,
                              /// initialized Set to true if the tick is initialized, i.e. liquidityGross is greater than 0, otherwise equal to false.
                              /// Outside values can only be used if the tick is initialized, i.e. if liquidityGross is greater than 0.
                              /// In addition, these values are only relative and must be used only in comparison to previous snapshots for
                              /// a specific position.
                              function ticks(int24 tick)
                                  external
                                  view
                                  returns (
                                      uint128 liquidityGross,
                                      int128 liquidityNet,
                                      uint256 feeGrowthOutside0X128,
                                      uint256 feeGrowthOutside1X128,
                                      int56 tickCumulativeOutside,
                                      uint160 secondsPerLiquidityOutsideX128,
                                      uint32 secondsOutside,
                                      bool initialized
                                  );
                              /// @notice Returns 256 packed tick initialized boolean values. See TickBitmap for more information
                              function tickBitmap(int16 wordPosition) external view returns (uint256);
                              /// @notice Returns the information about a position by the position's key
                              /// @param key The position's key is a hash of a preimage composed by the owner, tickLower and tickUpper
                              /// @return _liquidity The amount of liquidity in the position,
                              /// Returns feeGrowthInside0LastX128 fee growth of token0 inside the tick range as of the last mint/burn/poke,
                              /// Returns feeGrowthInside1LastX128 fee growth of token1 inside the tick range as of the last mint/burn/poke,
                              /// Returns tokensOwed0 the computed amount of token0 owed to the position as of the last mint/burn/poke,
                              /// Returns tokensOwed1 the computed amount of token1 owed to the position as of the last mint/burn/poke
                              function positions(bytes32 key)
                                  external
                                  view
                                  returns (
                                      uint128 _liquidity,
                                      uint256 feeGrowthInside0LastX128,
                                      uint256 feeGrowthInside1LastX128,
                                      uint128 tokensOwed0,
                                      uint128 tokensOwed1
                                  );
                              /// @notice Returns data about a specific observation index
                              /// @param index The element of the observations array to fetch
                              /// @dev You most likely want to use #observe() instead of this method to get an observation as of some amount of time
                              /// ago, rather than at a specific index in the array.
                              /// @return blockTimestamp The timestamp of the observation,
                              /// Returns tickCumulative the tick multiplied by seconds elapsed for the life of the pool as of the observation timestamp,
                              /// Returns secondsPerLiquidityCumulativeX128 the seconds per in range liquidity for the life of the pool as of the observation timestamp,
                              /// Returns initialized whether the observation has been initialized and the values are safe to use
                              function observations(uint256 index)
                                  external
                                  view
                                  returns (
                                      uint32 blockTimestamp,
                                      int56 tickCumulative,
                                      uint160 secondsPerLiquidityCumulativeX128,
                                      bool initialized
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that is not stored
                          /// @notice Contains view functions to provide information about the pool that is computed rather than stored on the
                          /// blockchain. The functions here may have variable gas costs.
                          interface IUniswapV3PoolDerivedState {
                              /// @notice Returns the cumulative tick and liquidity as of each timestamp `secondsAgo` from the current block timestamp
                              /// @dev To get a time weighted average tick or liquidity-in-range, you must call this with two values, one representing
                              /// the beginning of the period and another for the end of the period. E.g., to get the last hour time-weighted average tick,
                              /// you must call it with secondsAgos = [3600, 0].
                              /// @dev The time weighted average tick represents the geometric time weighted average price of the pool, in
                              /// log base sqrt(1.0001) of token1 / token0. The TickMath library can be used to go from a tick value to a ratio.
                              /// @param secondsAgos From how long ago each cumulative tick and liquidity value should be returned
                              /// @return tickCumulatives Cumulative tick values as of each `secondsAgos` from the current block timestamp
                              /// @return secondsPerLiquidityCumulativeX128s Cumulative seconds per liquidity-in-range value as of each `secondsAgos` from the current block
                              /// timestamp
                              function observe(uint32[] calldata secondsAgos)
                                  external
                                  view
                                  returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s);
                              /// @notice Returns a snapshot of the tick cumulative, seconds per liquidity and seconds inside a tick range
                              /// @dev Snapshots must only be compared to other snapshots, taken over a period for which a position existed.
                              /// I.e., snapshots cannot be compared if a position is not held for the entire period between when the first
                              /// snapshot is taken and the second snapshot is taken.
                              /// @param tickLower The lower tick of the range
                              /// @param tickUpper The upper tick of the range
                              /// @return tickCumulativeInside The snapshot of the tick accumulator for the range
                              /// @return secondsPerLiquidityInsideX128 The snapshot of seconds per liquidity for the range
                              /// @return secondsInside The snapshot of seconds per liquidity for the range
                              function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
                                  external
                                  view
                                  returns (
                                      int56 tickCumulativeInside,
                                      uint160 secondsPerLiquidityInsideX128,
                                      uint32 secondsInside
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Permissionless pool actions
                          /// @notice Contains pool methods that can be called by anyone
                          interface IUniswapV3PoolActions {
                              /// @notice Sets the initial price for the pool
                              /// @dev Price is represented as a sqrt(amountToken1/amountToken0) Q64.96 value
                              /// @param sqrtPriceX96 the initial sqrt price of the pool as a Q64.96
                              function initialize(uint160 sqrtPriceX96) external;
                              /// @notice Adds liquidity for the given recipient/tickLower/tickUpper position
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3MintCallback#uniswapV3MintCallback
                              /// in which they must pay any token0 or token1 owed for the liquidity. The amount of token0/token1 due depends
                              /// on tickLower, tickUpper, the amount of liquidity, and the current price.
                              /// @param recipient The address for which the liquidity will be created
                              /// @param tickLower The lower tick of the position in which to add liquidity
                              /// @param tickUpper The upper tick of the position in which to add liquidity
                              /// @param amount The amount of liquidity to mint
                              /// @param data Any data that should be passed through to the callback
                              /// @return amount0 The amount of token0 that was paid to mint the given amount of liquidity. Matches the value in the callback
                              /// @return amount1 The amount of token1 that was paid to mint the given amount of liquidity. Matches the value in the callback
                              function mint(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount,
                                  bytes calldata data
                              ) external returns (uint256 amount0, uint256 amount1);
                              /// @notice Collects tokens owed to a position
                              /// @dev Does not recompute fees earned, which must be done either via mint or burn of any amount of liquidity.
                              /// Collect must be called by the position owner. To withdraw only token0 or only token1, amount0Requested or
                              /// amount1Requested may be set to zero. To withdraw all tokens owed, caller may pass any value greater than the
                              /// actual tokens owed, e.g. type(uint128).max. Tokens owed may be from accumulated swap fees or burned liquidity.
                              /// @param recipient The address which should receive the fees collected
                              /// @param tickLower The lower tick of the position for which to collect fees
                              /// @param tickUpper The upper tick of the position for which to collect fees
                              /// @param amount0Requested How much token0 should be withdrawn from the fees owed
                              /// @param amount1Requested How much token1 should be withdrawn from the fees owed
                              /// @return amount0 The amount of fees collected in token0
                              /// @return amount1 The amount of fees collected in token1
                              function collect(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external returns (uint128 amount0, uint128 amount1);
                              /// @notice Burn liquidity from the sender and account tokens owed for the liquidity to the position
                              /// @dev Can be used to trigger a recalculation of fees owed to a position by calling with an amount of 0
                              /// @dev Fees must be collected separately via a call to #collect
                              /// @param tickLower The lower tick of the position for which to burn liquidity
                              /// @param tickUpper The upper tick of the position for which to burn liquidity
                              /// @param amount How much liquidity to burn
                              /// @return amount0 The amount of token0 sent to the recipient
                              /// @return amount1 The amount of token1 sent to the recipient
                              function burn(
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount
                              ) external returns (uint256 amount0, uint256 amount1);
                              /// @notice Swap token0 for token1, or token1 for token0
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
                              /// @param recipient The address to receive the output of the swap
                              /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
                              /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
                              /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
                              /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
                              /// @param data Any data to be passed through to the callback
                              /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
                              /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
                              function swap(
                                  address recipient,
                                  bool zeroForOne,
                                  int256 amountSpecified,
                                  uint160 sqrtPriceLimitX96,
                                  bytes calldata data
                              ) external returns (int256 amount0, int256 amount1);
                              /// @notice Receive token0 and/or token1 and pay it back, plus a fee, in the callback
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3FlashCallback#uniswapV3FlashCallback
                              /// @dev Can be used to donate underlying tokens pro-rata to currently in-range liquidity providers by calling
                              /// with 0 amount{0,1} and sending the donation amount(s) from the callback
                              /// @param recipient The address which will receive the token0 and token1 amounts
                              /// @param amount0 The amount of token0 to send
                              /// @param amount1 The amount of token1 to send
                              /// @param data Any data to be passed through to the callback
                              function flash(
                                  address recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  bytes calldata data
                              ) external;
                              /// @notice Increase the maximum number of price and liquidity observations that this pool will store
                              /// @dev This method is no-op if the pool already has an observationCardinalityNext greater than or equal to
                              /// the input observationCardinalityNext.
                              /// @param observationCardinalityNext The desired minimum number of observations for the pool to store
                              function increaseObservationCardinalityNext(uint16 observationCardinalityNext) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Permissioned pool actions
                          /// @notice Contains pool methods that may only be called by the factory owner
                          interface IUniswapV3PoolOwnerActions {
                              /// @notice Set the denominator of the protocol's % share of the fees
                              /// @param feeProtocol0 new protocol fee for token0 of the pool
                              /// @param feeProtocol1 new protocol fee for token1 of the pool
                              function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external;
                              /// @notice Collect the protocol fee accrued to the pool
                              /// @param recipient The address to which collected protocol fees should be sent
                              /// @param amount0Requested The maximum amount of token0 to send, can be 0 to collect fees in only token1
                              /// @param amount1Requested The maximum amount of token1 to send, can be 0 to collect fees in only token0
                              /// @return amount0 The protocol fee collected in token0
                              /// @return amount1 The protocol fee collected in token1
                              function collectProtocol(
                                  address recipient,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external returns (uint128 amount0, uint128 amount1);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Events emitted by a pool
                          /// @notice Contains all events emitted by the pool
                          interface IUniswapV3PoolEvents {
                              /// @notice Emitted exactly once by a pool when #initialize is first called on the pool
                              /// @dev Mint/Burn/Swap cannot be emitted by the pool before Initialize
                              /// @param sqrtPriceX96 The initial sqrt price of the pool, as a Q64.96
                              /// @param tick The initial tick of the pool, i.e. log base 1.0001 of the starting price of the pool
                              event Initialize(uint160 sqrtPriceX96, int24 tick);
                              /// @notice Emitted when liquidity is minted for a given position
                              /// @param sender The address that minted the liquidity
                              /// @param owner The owner of the position and recipient of any minted liquidity
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount The amount of liquidity minted to the position range
                              /// @param amount0 How much token0 was required for the minted liquidity
                              /// @param amount1 How much token1 was required for the minted liquidity
                              event Mint(
                                  address sender,
                                  address indexed owner,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount,
                                  uint256 amount0,
                                  uint256 amount1
                              );
                              /// @notice Emitted when fees are collected by the owner of a position
                              /// @dev Collect events may be emitted with zero amount0 and amount1 when the caller chooses not to collect fees
                              /// @param owner The owner of the position for which fees are collected
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount0 The amount of token0 fees collected
                              /// @param amount1 The amount of token1 fees collected
                              event Collect(
                                  address indexed owner,
                                  address recipient,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount0,
                                  uint128 amount1
                              );
                              /// @notice Emitted when a position's liquidity is removed
                              /// @dev Does not withdraw any fees earned by the liquidity position, which must be withdrawn via #collect
                              /// @param owner The owner of the position for which liquidity is removed
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount The amount of liquidity to remove
                              /// @param amount0 The amount of token0 withdrawn
                              /// @param amount1 The amount of token1 withdrawn
                              event Burn(
                                  address indexed owner,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount,
                                  uint256 amount0,
                                  uint256 amount1
                              );
                              /// @notice Emitted by the pool for any swaps between token0 and token1
                              /// @param sender The address that initiated the swap call, and that received the callback
                              /// @param recipient The address that received the output of the swap
                              /// @param amount0 The delta of the token0 balance of the pool
                              /// @param amount1 The delta of the token1 balance of the pool
                              /// @param sqrtPriceX96 The sqrt(price) of the pool after the swap, as a Q64.96
                              /// @param liquidity The liquidity of the pool after the swap
                              /// @param tick The log base 1.0001 of price of the pool after the swap
                              event Swap(
                                  address indexed sender,
                                  address indexed recipient,
                                  int256 amount0,
                                  int256 amount1,
                                  uint160 sqrtPriceX96,
                                  uint128 liquidity,
                                  int24 tick
                              );
                              /// @notice Emitted by the pool for any flashes of token0/token1
                              /// @param sender The address that initiated the swap call, and that received the callback
                              /// @param recipient The address that received the tokens from flash
                              /// @param amount0 The amount of token0 that was flashed
                              /// @param amount1 The amount of token1 that was flashed
                              /// @param paid0 The amount of token0 paid for the flash, which can exceed the amount0 plus the fee
                              /// @param paid1 The amount of token1 paid for the flash, which can exceed the amount1 plus the fee
                              event Flash(
                                  address indexed sender,
                                  address indexed recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  uint256 paid0,
                                  uint256 paid1
                              );
                              /// @notice Emitted by the pool for increases to the number of observations that can be stored
                              /// @dev observationCardinalityNext is not the observation cardinality until an observation is written at the index
                              /// just before a mint/swap/burn.
                              /// @param observationCardinalityNextOld The previous value of the next observation cardinality
                              /// @param observationCardinalityNextNew The updated value of the next observation cardinality
                              event IncreaseObservationCardinalityNext(
                                  uint16 observationCardinalityNextOld,
                                  uint16 observationCardinalityNextNew
                              );
                              /// @notice Emitted when the protocol fee is changed by the pool
                              /// @param feeProtocol0Old The previous value of the token0 protocol fee
                              /// @param feeProtocol1Old The previous value of the token1 protocol fee
                              /// @param feeProtocol0New The updated value of the token0 protocol fee
                              /// @param feeProtocol1New The updated value of the token1 protocol fee
                              event SetFeeProtocol(uint8 feeProtocol0Old, uint8 feeProtocol1Old, uint8 feeProtocol0New, uint8 feeProtocol1New);
                              /// @notice Emitted when the collected protocol fees are withdrawn by the factory owner
                              /// @param sender The address that collects the protocol fees
                              /// @param recipient The address that receives the collected protocol fees
                              /// @param amount0 The amount of token0 protocol fees that is withdrawn
                              /// @param amount0 The amount of token1 protocol fees that is withdrawn
                              event CollectProtocol(address indexed sender, address indexed recipient, uint128 amount0, uint128 amount1);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#swap
                          /// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
                          interface IUniswapV3SwapCallback {
                              /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
                              /// @dev In the implementation you must pay the pool tokens owed for the swap.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
                              /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
                              /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
                              function uniswapV3SwapCallback(
                                  int256 amount0Delta,
                                  int256 amount1Delta,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Immutable state
                          /// @notice Functions that return immutable state of the router
                          interface IPeripheryImmutableState {
                              /// @return Returns the address of the Uniswap V3 factory
                              function factory() external view returns (address);
                              /// @return Returns the address of WETH9
                              function WETH9() external view returns (address);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity =0.7.6;
                          /// @title Function for getting block timestamp
                          /// @dev Base contract that is overridden for tests
                          abstract contract BlockTimestamp {
                              /// @dev Method that exists purely to be overridden for tests
                              /// @return The current block timestamp
                              function _blockTimestamp() internal view virtual returns (uint256) {
                                  return block.timestamp;
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.7.0;
                          /**
                           * @dev Interface of the ERC20 standard as defined in the EIP.
                           */
                          interface IERC20 {
                              /**
                               * @dev Returns the amount of tokens in existence.
                               */
                              function totalSupply() external view returns (uint256);
                              /**
                               * @dev Returns the amount of tokens owned by `account`.
                               */
                              function balanceOf(address account) external view returns (uint256);
                              /**
                               * @dev Moves `amount` tokens from the caller's account to `recipient`.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transfer(address recipient, uint256 amount) external returns (bool);
                              /**
                               * @dev Returns the remaining number of tokens that `spender` will be
                               * allowed to spend on behalf of `owner` through {transferFrom}. This is
                               * zero by default.
                               *
                               * This value changes when {approve} or {transferFrom} are called.
                               */
                              function allowance(address owner, address spender) external view returns (uint256);
                              /**
                               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * IMPORTANT: Beware that changing an allowance with this method brings the risk
                               * that someone may use both the old and the new allowance by unfortunate
                               * transaction ordering. One possible solution to mitigate this race
                               * condition is to first reduce the spender's allowance to 0 and set the
                               * desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               *
                               * Emits an {Approval} event.
                               */
                              function approve(address spender, uint256 amount) external returns (bool);
                              /**
                               * @dev Moves `amount` tokens from `sender` to `recipient` using the
                               * allowance mechanism. `amount` is then deducted from the caller's
                               * allowance.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                              /**
                               * @dev Emitted when `value` tokens are moved from one account (`from`) to
                               * another (`to`).
                               *
                               * Note that `value` may be zero.
                               */
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              /**
                               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                               * a call to {approve}. `value` is the new allowance.
                               */
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.0;
                          /// @title Optimized overflow and underflow safe math operations
                          /// @notice Contains methods for doing math operations that revert on overflow or underflow for minimal gas cost
                          library LowGasSafeMath {
                              /// @notice Returns x + y, reverts if sum overflows uint256
                              /// @param x The augend
                              /// @param y The addend
                              /// @return z The sum of x and y
                              function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require((z = x + y) >= x);
                              }
                              /// @notice Returns x - y, reverts if underflows
                              /// @param x The minuend
                              /// @param y The subtrahend
                              /// @return z The difference of x and y
                              function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require((z = x - y) <= x);
                              }
                              /// @notice Returns x * y, reverts if overflows
                              /// @param x The multiplicand
                              /// @param y The multiplier
                              /// @return z The product of x and y
                              function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require(x == 0 || (z = x * y) / x == y);
                              }
                              /// @notice Returns x + y, reverts if overflows or underflows
                              /// @param x The augend
                              /// @param y The addend
                              /// @return z The sum of x and y
                              function add(int256 x, int256 y) internal pure returns (int256 z) {
                                  require((z = x + y) >= x == (y >= 0));
                              }
                              /// @notice Returns x - y, reverts if overflows or underflows
                              /// @param x The minuend
                              /// @param y The subtrahend
                              /// @return z The difference of x and y
                              function sub(int256 x, int256 y) internal pure returns (int256 z) {
                                  require((z = x - y) <= x == (y >= 0));
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
                          import '../interfaces/IPeripheryPayments.sol';
                          import '../interfaces/external/IWETH9.sol';
                          import '../libraries/TransferHelper.sol';
                          import './PeripheryImmutableState.sol';
                          abstract contract PeripheryPayments is IPeripheryPayments, PeripheryImmutableState {
                              receive() external payable {
                                  require(msg.sender == WETH9, 'Not WETH9');
                              }
                              /// @inheritdoc IPeripheryPayments
                              function unwrapWETH9(uint256 amountMinimum, address recipient) external payable override {
                                  uint256 balanceWETH9 = IWETH9(WETH9).balanceOf(address(this));
                                  require(balanceWETH9 >= amountMinimum, 'Insufficient WETH9');
                                  if (balanceWETH9 > 0) {
                                      IWETH9(WETH9).withdraw(balanceWETH9);
                                      TransferHelper.safeTransferETH(recipient, balanceWETH9);
                                  }
                              }
                              /// @inheritdoc IPeripheryPayments
                              function sweepToken(
                                  address token,
                                  uint256 amountMinimum,
                                  address recipient
                              ) external payable override {
                                  uint256 balanceToken = IERC20(token).balanceOf(address(this));
                                  require(balanceToken >= amountMinimum, 'Insufficient token');
                                  if (balanceToken > 0) {
                                      TransferHelper.safeTransfer(token, recipient, balanceToken);
                                  }
                              }
                              /// @inheritdoc IPeripheryPayments
                              function refundETH() external payable override {
                                  if (address(this).balance > 0) TransferHelper.safeTransferETH(msg.sender, address(this).balance);
                              }
                              /// @param token The token to pay
                              /// @param payer The entity that must pay
                              /// @param recipient The entity that will receive payment
                              /// @param value The amount to pay
                              function pay(
                                  address token,
                                  address payer,
                                  address recipient,
                                  uint256 value
                              ) internal {
                                  if (token == WETH9 && address(this).balance >= value) {
                                      // pay with WETH9
                                      IWETH9(WETH9).deposit{value: value}(); // wrap only what is needed to pay
                                      IWETH9(WETH9).transfer(recipient, value);
                                  } else if (payer == address(this)) {
                                      // pay with tokens already in the contract (for the exact input multihop case)
                                      TransferHelper.safeTransfer(token, recipient, value);
                                  } else {
                                      // pull payment
                                      TransferHelper.safeTransferFrom(token, payer, recipient, value);
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          import './IPeripheryPayments.sol';
                          /// @title Periphery Payments
                          /// @notice Functions to ease deposits and withdrawals of ETH
                          interface IPeripheryPaymentsWithFee is IPeripheryPayments {
                              /// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH, with a percentage between
                              /// 0 (exclusive), and 1 (inclusive) going to feeRecipient
                              /// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
                              function unwrapWETH9WithFee(
                                  uint256 amountMinimum,
                                  address recipient,
                                  uint256 feeBips,
                                  address feeRecipient
                              ) external payable;
                              /// @notice Transfers the full amount of a token held by this contract to recipient, with a percentage between
                              /// 0 (exclusive) and 1 (inclusive) going to feeRecipient
                              /// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
                              function sweepTokenWithFee(
                                  address token,
                                  uint256 amountMinimum,
                                  address recipient,
                                  uint256 feeBips,
                                  address feeRecipient
                              ) external payable;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.6.0;
                          import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
                          library TransferHelper {
                              /// @notice Transfers tokens from the targeted address to the given destination
                              /// @notice Errors with 'STF' if transfer fails
                              /// @param token The contract address of the token to be transferred
                              /// @param from The originating address from which the tokens will be transferred
                              /// @param to The destination address of the transfer
                              /// @param value The amount to be transferred
                              function safeTransferFrom(
                                  address token,
                                  address from,
                                  address to,
                                  uint256 value
                              ) internal {
                                  (bool success, bytes memory data) =
                                      token.call(abi.encodeWithSelector(IERC20.transferFrom.selector, from, to, value));
                                  require(success && (data.length == 0 || abi.decode(data, (bool))), 'STF');
                              }
                              /// @notice Transfers tokens from msg.sender to a recipient
                              /// @dev Errors with ST if transfer fails
                              /// @param token The contract address of the token which will be transferred
                              /// @param to The recipient of the transfer
                              /// @param value The value of the transfer
                              function safeTransfer(
                                  address token,
                                  address to,
                                  uint256 value
                              ) internal {
                                  (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
                                  require(success && (data.length == 0 || abi.decode(data, (bool))), 'ST');
                              }
                              /// @notice Approves the stipulated contract to spend the given allowance in the given token
                              /// @dev Errors with 'SA' if transfer fails
                              /// @param token The contract address of the token to be approved
                              /// @param to The target of the approval
                              /// @param value The amount of the given token the target will be allowed to spend
                              function safeApprove(
                                  address token,
                                  address to,
                                  uint256 value
                              ) internal {
                                  (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.approve.selector, to, value));
                                  require(success && (data.length == 0 || abi.decode(data, (bool))), 'SA');
                              }
                              /// @notice Transfers ETH to the recipient address
                              /// @dev Fails with `STE`
                              /// @param to The destination of the transfer
                              /// @param value The value to be transferred
                              function safeTransferETH(address to, uint256 value) internal {
                                  (bool success, ) = to.call{value: value}(new bytes(0));
                                  require(success, 'STE');
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          /// @title Periphery Payments
                          /// @notice Functions to ease deposits and withdrawals of ETH
                          interface IPeripheryPayments {
                              /// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH.
                              /// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
                              /// @param amountMinimum The minimum amount of WETH9 to unwrap
                              /// @param recipient The address receiving ETH
                              function unwrapWETH9(uint256 amountMinimum, address recipient) external payable;
                              /// @notice Refunds any ETH balance held by this contract to the `msg.sender`
                              /// @dev Useful for bundling with mint or increase liquidity that uses ether, or exact output swaps
                              /// that use ether for the input amount
                              function refundETH() external payable;
                              /// @notice Transfers the full amount of a token held by this contract to recipient
                              /// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
                              /// @param token The contract address of the token which will be transferred to `recipient`
                              /// @param amountMinimum The minimum amount of token required for a transfer
                              /// @param recipient The destination address of the token
                              function sweepToken(
                                  address token,
                                  uint256 amountMinimum,
                                  address recipient
                              ) external payable;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          pragma abicoder v2;
                          /// @title Multicall interface
                          /// @notice Enables calling multiple methods in a single call to the contract
                          interface IMulticall {
                              /// @notice Call multiple functions in the current contract and return the data from all of them if they all succeed
                              /// @dev The `msg.value` should not be trusted for any method callable from multicall.
                              /// @param data The encoded function data for each of the calls to make to this contract
                              /// @return results The results from each of the calls passed in via data
                              function multicall(bytes[] calldata data) external payable returns (bytes[] memory results);
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.6.0 <0.8.0;
                          /**
                           * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
                           * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
                           *
                           * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
                           * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
                           * need to send a transaction, and thus is not required to hold Ether at all.
                           */
                          interface IERC20Permit {
                              /**
                               * @dev Sets `value` as the allowance of `spender` over `owner`'s tokens,
                               * given `owner`'s signed approval.
                               *
                               * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                               * ordering also apply here.
                               *
                               * Emits an {Approval} event.
                               *
                               * Requirements:
                               *
                               * - `spender` cannot be the zero address.
                               * - `deadline` must be a timestamp in the future.
                               * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                               * over the EIP712-formatted function arguments.
                               * - the signature must use ``owner``'s current nonce (see {nonces}).
                               *
                               * For more information on the signature format, see the
                               * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                               * section].
                               */
                              function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;
                              /**
                               * @dev Returns the current nonce for `owner`. This value must be
                               * included whenever a signature is generated for {permit}.
                               *
                               * Every successful call to {permit} increases ``owner``'s nonce by one. This
                               * prevents a signature from being used multiple times.
                               */
                              function nonces(address owner) external view returns (uint256);
                              /**
                               * @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
                               */
                              // solhint-disable-next-line func-name-mixedcase
                              function DOMAIN_SEPARATOR() external view returns (bytes32);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.5;
                          /// @title Self Permit
                          /// @notice Functionality to call permit on any EIP-2612-compliant token for use in the route
                          interface ISelfPermit {
                              /// @notice Permits this contract to spend a given token from `msg.sender`
                              /// @dev The `owner` is always msg.sender and the `spender` is always address(this).
                              /// @param token The address of the token spent
                              /// @param value The amount that can be spent of token
                              /// @param deadline A timestamp, the current blocktime must be less than or equal to this timestamp
                              /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                              /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                              /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                              function selfPermit(
                                  address token,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external payable;
                              /// @notice Permits this contract to spend a given token from `msg.sender`
                              /// @dev The `owner` is always msg.sender and the `spender` is always address(this).
                              /// Can be used instead of #selfPermit to prevent calls from failing due to a frontrun of a call to #selfPermit
                              /// @param token The address of the token spent
                              /// @param value The amount that can be spent of token
                              /// @param deadline A timestamp, the current blocktime must be less than or equal to this timestamp
                              /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                              /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                              /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                              function selfPermitIfNecessary(
                                  address token,
                                  uint256 value,
                                  uint256 deadline,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external payable;
                              /// @notice Permits this contract to spend the sender's tokens for permit signatures that have the `allowed` parameter
                              /// @dev The `owner` is always msg.sender and the `spender` is always address(this)
                              /// @param token The address of the token spent
                              /// @param nonce The current nonce of the owner
                              /// @param expiry The timestamp at which the permit is no longer valid
                              /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                              /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                              /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                              function selfPermitAllowed(
                                  address token,
                                  uint256 nonce,
                                  uint256 expiry,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external payable;
                              /// @notice Permits this contract to spend the sender's tokens for permit signatures that have the `allowed` parameter
                              /// @dev The `owner` is always msg.sender and the `spender` is always address(this)
                              /// Can be used instead of #selfPermitAllowed to prevent calls from failing due to a frontrun of a call to #selfPermitAllowed.
                              /// @param token The address of the token spent
                              /// @param nonce The current nonce of the owner
                              /// @param expiry The timestamp at which the permit is no longer valid
                              /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                              /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                              /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                              function selfPermitAllowedIfNecessary(
                                  address token,
                                  uint256 nonce,
                                  uint256 expiry,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external payable;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Interface for permit
                          /// @notice Interface used by DAI/CHAI for permit
                          interface IERC20PermitAllowed {
                              /// @notice Approve the spender to spend some tokens via the holder signature
                              /// @dev This is the permit interface used by DAI and CHAI
                              /// @param holder The address of the token holder, the token owner
                              /// @param spender The address of the token spender
                              /// @param nonce The holder's nonce, increases at each call to permit
                              /// @param expiry The timestamp at which the permit is no longer valid
                              /// @param allowed Boolean that sets approval amount, true for type(uint256).max and false for 0
                              /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                              /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                              /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                              function permit(
                                  address holder,
                                  address spender,
                                  uint256 nonce,
                                  uint256 expiry,
                                  bool allowed,
                                  uint8 v,
                                  bytes32 r,
                                  bytes32 s
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          /*
                           * @title Solidity Bytes Arrays Utils
                           * @author Gonçalo Sá <[email protected]>
                           *
                           * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
                           *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
                           */
                          pragma solidity >=0.5.0 <0.8.0;
                          library BytesLib {
                              function slice(
                                  bytes memory _bytes,
                                  uint256 _start,
                                  uint256 _length
                              ) internal pure returns (bytes memory) {
                                  require(_length + 31 >= _length, 'slice_overflow');
                                  require(_start + _length >= _start, 'slice_overflow');
                                  require(_bytes.length >= _start + _length, 'slice_outOfBounds');
                                  bytes memory tempBytes;
                                  assembly {
                                      switch iszero(_length)
                                          case 0 {
                                              // Get a location of some free memory and store it in tempBytes as
                                              // Solidity does for memory variables.
                                              tempBytes := mload(0x40)
                                              // The first word of the slice result is potentially a partial
                                              // word read from the original array. To read it, we calculate
                                              // the length of that partial word and start copying that many
                                              // bytes into the array. The first word we copy will start with
                                              // data we don't care about, but the last `lengthmod` bytes will
                                              // land at the beginning of the contents of the new array. When
                                              // we're done copying, we overwrite the full first word with
                                              // the actual length of the slice.
                                              let lengthmod := and(_length, 31)
                                              // The multiplication in the next line is necessary
                                              // because when slicing multiples of 32 bytes (lengthmod == 0)
                                              // the following copy loop was copying the origin's length
                                              // and then ending prematurely not copying everything it should.
                                              let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                                              let end := add(mc, _length)
                                              for {
                                                  // The multiplication in the next line has the same exact purpose
                                                  // as the one above.
                                                  let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                                              } lt(mc, end) {
                                                  mc := add(mc, 0x20)
                                                  cc := add(cc, 0x20)
                                              } {
                                                  mstore(mc, mload(cc))
                                              }
                                              mstore(tempBytes, _length)
                                              //update free-memory pointer
                                              //allocating the array padded to 32 bytes like the compiler does now
                                              mstore(0x40, and(add(mc, 31), not(31)))
                                          }
                                          //if we want a zero-length slice let's just return a zero-length array
                                          default {
                                              tempBytes := mload(0x40)
                                              //zero out the 32 bytes slice we are about to return
                                              //we need to do it because Solidity does not garbage collect
                                              mstore(tempBytes, 0)
                                              mstore(0x40, add(tempBytes, 0x20))
                                          }
                                  }
                                  return tempBytes;
                              }
                              function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                                  require(_start + 20 >= _start, 'toAddress_overflow');
                                  require(_bytes.length >= _start + 20, 'toAddress_outOfBounds');
                                  address tempAddress;
                                  assembly {
                                      tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                                  }
                                  return tempAddress;
                              }
                              function toUint24(bytes memory _bytes, uint256 _start) internal pure returns (uint24) {
                                  require(_start + 3 >= _start, 'toUint24_overflow');
                                  require(_bytes.length >= _start + 3, 'toUint24_outOfBounds');
                                  uint24 tempUint;
                                  assembly {
                                      tempUint := mload(add(add(_bytes, 0x3), _start))
                                  }
                                  return tempUint;
                              }
                          }
                          

                          File 6 of 13: WETH9
                          // Copyright (C) 2015, 2016, 2017 Dapphub
                          
                          // This program is free software: you can redistribute it and/or modify
                          // it under the terms of the GNU General Public License as published by
                          // the Free Software Foundation, either version 3 of the License, or
                          // (at your option) any later version.
                          
                          // This program is distributed in the hope that it will be useful,
                          // but WITHOUT ANY WARRANTY; without even the implied warranty of
                          // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                          // GNU General Public License for more details.
                          
                          // You should have received a copy of the GNU General Public License
                          // along with this program.  If not, see <http://www.gnu.org/licenses/>.
                          
                          pragma solidity ^0.4.18;
                          
                          contract WETH9 {
                              string public name     = "Wrapped Ether";
                              string public symbol   = "WETH";
                              uint8  public decimals = 18;
                          
                              event  Approval(address indexed src, address indexed guy, uint wad);
                              event  Transfer(address indexed src, address indexed dst, uint wad);
                              event  Deposit(address indexed dst, uint wad);
                              event  Withdrawal(address indexed src, uint wad);
                          
                              mapping (address => uint)                       public  balanceOf;
                              mapping (address => mapping (address => uint))  public  allowance;
                          
                              function() public payable {
                                  deposit();
                              }
                              function deposit() public payable {
                                  balanceOf[msg.sender] += msg.value;
                                  Deposit(msg.sender, msg.value);
                              }
                              function withdraw(uint wad) public {
                                  require(balanceOf[msg.sender] >= wad);
                                  balanceOf[msg.sender] -= wad;
                                  msg.sender.transfer(wad);
                                  Withdrawal(msg.sender, wad);
                              }
                          
                              function totalSupply() public view returns (uint) {
                                  return this.balance;
                              }
                          
                              function approve(address guy, uint wad) public returns (bool) {
                                  allowance[msg.sender][guy] = wad;
                                  Approval(msg.sender, guy, wad);
                                  return true;
                              }
                          
                              function transfer(address dst, uint wad) public returns (bool) {
                                  return transferFrom(msg.sender, dst, wad);
                              }
                          
                              function transferFrom(address src, address dst, uint wad)
                                  public
                                  returns (bool)
                              {
                                  require(balanceOf[src] >= wad);
                          
                                  if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
                                      require(allowance[src][msg.sender] >= wad);
                                      allowance[src][msg.sender] -= wad;
                                  }
                          
                                  balanceOf[src] -= wad;
                                  balanceOf[dst] += wad;
                          
                                  Transfer(src, dst, wad);
                          
                                  return true;
                              }
                          }
                          
                          
                          /*
                                              GNU GENERAL PUBLIC LICENSE
                                                 Version 3, 29 June 2007
                          
                           Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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                          File 7 of 13: UniswapV3Pool
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity =0.7.6;
                          import './interfaces/IUniswapV3Pool.sol';
                          import './NoDelegateCall.sol';
                          import './libraries/LowGasSafeMath.sol';
                          import './libraries/SafeCast.sol';
                          import './libraries/Tick.sol';
                          import './libraries/TickBitmap.sol';
                          import './libraries/Position.sol';
                          import './libraries/Oracle.sol';
                          import './libraries/FullMath.sol';
                          import './libraries/FixedPoint128.sol';
                          import './libraries/TransferHelper.sol';
                          import './libraries/TickMath.sol';
                          import './libraries/LiquidityMath.sol';
                          import './libraries/SqrtPriceMath.sol';
                          import './libraries/SwapMath.sol';
                          import './interfaces/IUniswapV3PoolDeployer.sol';
                          import './interfaces/IUniswapV3Factory.sol';
                          import './interfaces/IERC20Minimal.sol';
                          import './interfaces/callback/IUniswapV3MintCallback.sol';
                          import './interfaces/callback/IUniswapV3SwapCallback.sol';
                          import './interfaces/callback/IUniswapV3FlashCallback.sol';
                          contract UniswapV3Pool is IUniswapV3Pool, NoDelegateCall {
                              using LowGasSafeMath for uint256;
                              using LowGasSafeMath for int256;
                              using SafeCast for uint256;
                              using SafeCast for int256;
                              using Tick for mapping(int24 => Tick.Info);
                              using TickBitmap for mapping(int16 => uint256);
                              using Position for mapping(bytes32 => Position.Info);
                              using Position for Position.Info;
                              using Oracle for Oracle.Observation[65535];
                              /// @inheritdoc IUniswapV3PoolImmutables
                              address public immutable override factory;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              address public immutable override token0;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              address public immutable override token1;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              uint24 public immutable override fee;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              int24 public immutable override tickSpacing;
                              /// @inheritdoc IUniswapV3PoolImmutables
                              uint128 public immutable override maxLiquidityPerTick;
                              struct Slot0 {
                                  // the current price
                                  uint160 sqrtPriceX96;
                                  // the current tick
                                  int24 tick;
                                  // the most-recently updated index of the observations array
                                  uint16 observationIndex;
                                  // the current maximum number of observations that are being stored
                                  uint16 observationCardinality;
                                  // the next maximum number of observations to store, triggered in observations.write
                                  uint16 observationCardinalityNext;
                                  // the current protocol fee as a percentage of the swap fee taken on withdrawal
                                  // represented as an integer denominator (1/x)%
                                  uint8 feeProtocol;
                                  // whether the pool is locked
                                  bool unlocked;
                              }
                              /// @inheritdoc IUniswapV3PoolState
                              Slot0 public override slot0;
                              /// @inheritdoc IUniswapV3PoolState
                              uint256 public override feeGrowthGlobal0X128;
                              /// @inheritdoc IUniswapV3PoolState
                              uint256 public override feeGrowthGlobal1X128;
                              // accumulated protocol fees in token0/token1 units
                              struct ProtocolFees {
                                  uint128 token0;
                                  uint128 token1;
                              }
                              /// @inheritdoc IUniswapV3PoolState
                              ProtocolFees public override protocolFees;
                              /// @inheritdoc IUniswapV3PoolState
                              uint128 public override liquidity;
                              /// @inheritdoc IUniswapV3PoolState
                              mapping(int24 => Tick.Info) public override ticks;
                              /// @inheritdoc IUniswapV3PoolState
                              mapping(int16 => uint256) public override tickBitmap;
                              /// @inheritdoc IUniswapV3PoolState
                              mapping(bytes32 => Position.Info) public override positions;
                              /// @inheritdoc IUniswapV3PoolState
                              Oracle.Observation[65535] public override observations;
                              /// @dev Mutually exclusive reentrancy protection into the pool to/from a method. This method also prevents entrance
                              /// to a function before the pool is initialized. The reentrancy guard is required throughout the contract because
                              /// we use balance checks to determine the payment status of interactions such as mint, swap and flash.
                              modifier lock() {
                                  require(slot0.unlocked, 'LOK');
                                  slot0.unlocked = false;
                                  _;
                                  slot0.unlocked = true;
                              }
                              /// @dev Prevents calling a function from anyone except the address returned by IUniswapV3Factory#owner()
                              modifier onlyFactoryOwner() {
                                  require(msg.sender == IUniswapV3Factory(factory).owner());
                                  _;
                              }
                              constructor() {
                                  int24 _tickSpacing;
                                  (factory, token0, token1, fee, _tickSpacing) = IUniswapV3PoolDeployer(msg.sender).parameters();
                                  tickSpacing = _tickSpacing;
                                  maxLiquidityPerTick = Tick.tickSpacingToMaxLiquidityPerTick(_tickSpacing);
                              }
                              /// @dev Common checks for valid tick inputs.
                              function checkTicks(int24 tickLower, int24 tickUpper) private pure {
                                  require(tickLower < tickUpper, 'TLU');
                                  require(tickLower >= TickMath.MIN_TICK, 'TLM');
                                  require(tickUpper <= TickMath.MAX_TICK, 'TUM');
                              }
                              /// @dev Returns the block timestamp truncated to 32 bits, i.e. mod 2**32. This method is overridden in tests.
                              function _blockTimestamp() internal view virtual returns (uint32) {
                                  return uint32(block.timestamp); // truncation is desired
                              }
                              /// @dev Get the pool's balance of token0
                              /// @dev This function is gas optimized to avoid a redundant extcodesize check in addition to the returndatasize
                              /// check
                              function balance0() private view returns (uint256) {
                                  (bool success, bytes memory data) =
                                      token0.staticcall(abi.encodeWithSelector(IERC20Minimal.balanceOf.selector, address(this)));
                                  require(success && data.length >= 32);
                                  return abi.decode(data, (uint256));
                              }
                              /// @dev Get the pool's balance of token1
                              /// @dev This function is gas optimized to avoid a redundant extcodesize check in addition to the returndatasize
                              /// check
                              function balance1() private view returns (uint256) {
                                  (bool success, bytes memory data) =
                                      token1.staticcall(abi.encodeWithSelector(IERC20Minimal.balanceOf.selector, address(this)));
                                  require(success && data.length >= 32);
                                  return abi.decode(data, (uint256));
                              }
                              /// @inheritdoc IUniswapV3PoolDerivedState
                              function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
                                  external
                                  view
                                  override
                                  noDelegateCall
                                  returns (
                                      int56 tickCumulativeInside,
                                      uint160 secondsPerLiquidityInsideX128,
                                      uint32 secondsInside
                                  )
                              {
                                  checkTicks(tickLower, tickUpper);
                                  int56 tickCumulativeLower;
                                  int56 tickCumulativeUpper;
                                  uint160 secondsPerLiquidityOutsideLowerX128;
                                  uint160 secondsPerLiquidityOutsideUpperX128;
                                  uint32 secondsOutsideLower;
                                  uint32 secondsOutsideUpper;
                                  {
                                      Tick.Info storage lower = ticks[tickLower];
                                      Tick.Info storage upper = ticks[tickUpper];
                                      bool initializedLower;
                                      (tickCumulativeLower, secondsPerLiquidityOutsideLowerX128, secondsOutsideLower, initializedLower) = (
                                          lower.tickCumulativeOutside,
                                          lower.secondsPerLiquidityOutsideX128,
                                          lower.secondsOutside,
                                          lower.initialized
                                      );
                                      require(initializedLower);
                                      bool initializedUpper;
                                      (tickCumulativeUpper, secondsPerLiquidityOutsideUpperX128, secondsOutsideUpper, initializedUpper) = (
                                          upper.tickCumulativeOutside,
                                          upper.secondsPerLiquidityOutsideX128,
                                          upper.secondsOutside,
                                          upper.initialized
                                      );
                                      require(initializedUpper);
                                  }
                                  Slot0 memory _slot0 = slot0;
                                  if (_slot0.tick < tickLower) {
                                      return (
                                          tickCumulativeLower - tickCumulativeUpper,
                                          secondsPerLiquidityOutsideLowerX128 - secondsPerLiquidityOutsideUpperX128,
                                          secondsOutsideLower - secondsOutsideUpper
                                      );
                                  } else if (_slot0.tick < tickUpper) {
                                      uint32 time = _blockTimestamp();
                                      (int56 tickCumulative, uint160 secondsPerLiquidityCumulativeX128) =
                                          observations.observeSingle(
                                              time,
                                              0,
                                              _slot0.tick,
                                              _slot0.observationIndex,
                                              liquidity,
                                              _slot0.observationCardinality
                                          );
                                      return (
                                          tickCumulative - tickCumulativeLower - tickCumulativeUpper,
                                          secondsPerLiquidityCumulativeX128 -
                                              secondsPerLiquidityOutsideLowerX128 -
                                              secondsPerLiquidityOutsideUpperX128,
                                          time - secondsOutsideLower - secondsOutsideUpper
                                      );
                                  } else {
                                      return (
                                          tickCumulativeUpper - tickCumulativeLower,
                                          secondsPerLiquidityOutsideUpperX128 - secondsPerLiquidityOutsideLowerX128,
                                          secondsOutsideUpper - secondsOutsideLower
                                      );
                                  }
                              }
                              /// @inheritdoc IUniswapV3PoolDerivedState
                              function observe(uint32[] calldata secondsAgos)
                                  external
                                  view
                                  override
                                  noDelegateCall
                                  returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s)
                              {
                                  return
                                      observations.observe(
                                          _blockTimestamp(),
                                          secondsAgos,
                                          slot0.tick,
                                          slot0.observationIndex,
                                          liquidity,
                                          slot0.observationCardinality
                                      );
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function increaseObservationCardinalityNext(uint16 observationCardinalityNext)
                                  external
                                  override
                                  lock
                                  noDelegateCall
                              {
                                  uint16 observationCardinalityNextOld = slot0.observationCardinalityNext; // for the event
                                  uint16 observationCardinalityNextNew =
                                      observations.grow(observationCardinalityNextOld, observationCardinalityNext);
                                  slot0.observationCardinalityNext = observationCardinalityNextNew;
                                  if (observationCardinalityNextOld != observationCardinalityNextNew)
                                      emit IncreaseObservationCardinalityNext(observationCardinalityNextOld, observationCardinalityNextNew);
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              /// @dev not locked because it initializes unlocked
                              function initialize(uint160 sqrtPriceX96) external override {
                                  require(slot0.sqrtPriceX96 == 0, 'AI');
                                  int24 tick = TickMath.getTickAtSqrtRatio(sqrtPriceX96);
                                  (uint16 cardinality, uint16 cardinalityNext) = observations.initialize(_blockTimestamp());
                                  slot0 = Slot0({
                                      sqrtPriceX96: sqrtPriceX96,
                                      tick: tick,
                                      observationIndex: 0,
                                      observationCardinality: cardinality,
                                      observationCardinalityNext: cardinalityNext,
                                      feeProtocol: 0,
                                      unlocked: true
                                  });
                                  emit Initialize(sqrtPriceX96, tick);
                              }
                              struct ModifyPositionParams {
                                  // the address that owns the position
                                  address owner;
                                  // the lower and upper tick of the position
                                  int24 tickLower;
                                  int24 tickUpper;
                                  // any change in liquidity
                                  int128 liquidityDelta;
                              }
                              /// @dev Effect some changes to a position
                              /// @param params the position details and the change to the position's liquidity to effect
                              /// @return position a storage pointer referencing the position with the given owner and tick range
                              /// @return amount0 the amount of token0 owed to the pool, negative if the pool should pay the recipient
                              /// @return amount1 the amount of token1 owed to the pool, negative if the pool should pay the recipient
                              function _modifyPosition(ModifyPositionParams memory params)
                                  private
                                  noDelegateCall
                                  returns (
                                      Position.Info storage position,
                                      int256 amount0,
                                      int256 amount1
                                  )
                              {
                                  checkTicks(params.tickLower, params.tickUpper);
                                  Slot0 memory _slot0 = slot0; // SLOAD for gas optimization
                                  position = _updatePosition(
                                      params.owner,
                                      params.tickLower,
                                      params.tickUpper,
                                      params.liquidityDelta,
                                      _slot0.tick
                                  );
                                  if (params.liquidityDelta != 0) {
                                      if (_slot0.tick < params.tickLower) {
                                          // current tick is below the passed range; liquidity can only become in range by crossing from left to
                                          // right, when we'll need _more_ token0 (it's becoming more valuable) so user must provide it
                                          amount0 = SqrtPriceMath.getAmount0Delta(
                                              TickMath.getSqrtRatioAtTick(params.tickLower),
                                              TickMath.getSqrtRatioAtTick(params.tickUpper),
                                              params.liquidityDelta
                                          );
                                      } else if (_slot0.tick < params.tickUpper) {
                                          // current tick is inside the passed range
                                          uint128 liquidityBefore = liquidity; // SLOAD for gas optimization
                                          // write an oracle entry
                                          (slot0.observationIndex, slot0.observationCardinality) = observations.write(
                                              _slot0.observationIndex,
                                              _blockTimestamp(),
                                              _slot0.tick,
                                              liquidityBefore,
                                              _slot0.observationCardinality,
                                              _slot0.observationCardinalityNext
                                          );
                                          amount0 = SqrtPriceMath.getAmount0Delta(
                                              _slot0.sqrtPriceX96,
                                              TickMath.getSqrtRatioAtTick(params.tickUpper),
                                              params.liquidityDelta
                                          );
                                          amount1 = SqrtPriceMath.getAmount1Delta(
                                              TickMath.getSqrtRatioAtTick(params.tickLower),
                                              _slot0.sqrtPriceX96,
                                              params.liquidityDelta
                                          );
                                          liquidity = LiquidityMath.addDelta(liquidityBefore, params.liquidityDelta);
                                      } else {
                                          // current tick is above the passed range; liquidity can only become in range by crossing from right to
                                          // left, when we'll need _more_ token1 (it's becoming more valuable) so user must provide it
                                          amount1 = SqrtPriceMath.getAmount1Delta(
                                              TickMath.getSqrtRatioAtTick(params.tickLower),
                                              TickMath.getSqrtRatioAtTick(params.tickUpper),
                                              params.liquidityDelta
                                          );
                                      }
                                  }
                              }
                              /// @dev Gets and updates a position with the given liquidity delta
                              /// @param owner the owner of the position
                              /// @param tickLower the lower tick of the position's tick range
                              /// @param tickUpper the upper tick of the position's tick range
                              /// @param tick the current tick, passed to avoid sloads
                              function _updatePosition(
                                  address owner,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  int128 liquidityDelta,
                                  int24 tick
                              ) private returns (Position.Info storage position) {
                                  position = positions.get(owner, tickLower, tickUpper);
                                  uint256 _feeGrowthGlobal0X128 = feeGrowthGlobal0X128; // SLOAD for gas optimization
                                  uint256 _feeGrowthGlobal1X128 = feeGrowthGlobal1X128; // SLOAD for gas optimization
                                  // if we need to update the ticks, do it
                                  bool flippedLower;
                                  bool flippedUpper;
                                  if (liquidityDelta != 0) {
                                      uint32 time = _blockTimestamp();
                                      (int56 tickCumulative, uint160 secondsPerLiquidityCumulativeX128) =
                                          observations.observeSingle(
                                              time,
                                              0,
                                              slot0.tick,
                                              slot0.observationIndex,
                                              liquidity,
                                              slot0.observationCardinality
                                          );
                                      flippedLower = ticks.update(
                                          tickLower,
                                          tick,
                                          liquidityDelta,
                                          _feeGrowthGlobal0X128,
                                          _feeGrowthGlobal1X128,
                                          secondsPerLiquidityCumulativeX128,
                                          tickCumulative,
                                          time,
                                          false,
                                          maxLiquidityPerTick
                                      );
                                      flippedUpper = ticks.update(
                                          tickUpper,
                                          tick,
                                          liquidityDelta,
                                          _feeGrowthGlobal0X128,
                                          _feeGrowthGlobal1X128,
                                          secondsPerLiquidityCumulativeX128,
                                          tickCumulative,
                                          time,
                                          true,
                                          maxLiquidityPerTick
                                      );
                                      if (flippedLower) {
                                          tickBitmap.flipTick(tickLower, tickSpacing);
                                      }
                                      if (flippedUpper) {
                                          tickBitmap.flipTick(tickUpper, tickSpacing);
                                      }
                                  }
                                  (uint256 feeGrowthInside0X128, uint256 feeGrowthInside1X128) =
                                      ticks.getFeeGrowthInside(tickLower, tickUpper, tick, _feeGrowthGlobal0X128, _feeGrowthGlobal1X128);
                                  position.update(liquidityDelta, feeGrowthInside0X128, feeGrowthInside1X128);
                                  // clear any tick data that is no longer needed
                                  if (liquidityDelta < 0) {
                                      if (flippedLower) {
                                          ticks.clear(tickLower);
                                      }
                                      if (flippedUpper) {
                                          ticks.clear(tickUpper);
                                      }
                                  }
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              /// @dev noDelegateCall is applied indirectly via _modifyPosition
                              function mint(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount,
                                  bytes calldata data
                              ) external override lock returns (uint256 amount0, uint256 amount1) {
                                  require(amount > 0);
                                  (, int256 amount0Int, int256 amount1Int) =
                                      _modifyPosition(
                                          ModifyPositionParams({
                                              owner: recipient,
                                              tickLower: tickLower,
                                              tickUpper: tickUpper,
                                              liquidityDelta: int256(amount).toInt128()
                                          })
                                      );
                                  amount0 = uint256(amount0Int);
                                  amount1 = uint256(amount1Int);
                                  uint256 balance0Before;
                                  uint256 balance1Before;
                                  if (amount0 > 0) balance0Before = balance0();
                                  if (amount1 > 0) balance1Before = balance1();
                                  IUniswapV3MintCallback(msg.sender).uniswapV3MintCallback(amount0, amount1, data);
                                  if (amount0 > 0) require(balance0Before.add(amount0) <= balance0(), 'M0');
                                  if (amount1 > 0) require(balance1Before.add(amount1) <= balance1(), 'M1');
                                  emit Mint(msg.sender, recipient, tickLower, tickUpper, amount, amount0, amount1);
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function collect(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external override lock returns (uint128 amount0, uint128 amount1) {
                                  // we don't need to checkTicks here, because invalid positions will never have non-zero tokensOwed{0,1}
                                  Position.Info storage position = positions.get(msg.sender, tickLower, tickUpper);
                                  amount0 = amount0Requested > position.tokensOwed0 ? position.tokensOwed0 : amount0Requested;
                                  amount1 = amount1Requested > position.tokensOwed1 ? position.tokensOwed1 : amount1Requested;
                                  if (amount0 > 0) {
                                      position.tokensOwed0 -= amount0;
                                      TransferHelper.safeTransfer(token0, recipient, amount0);
                                  }
                                  if (amount1 > 0) {
                                      position.tokensOwed1 -= amount1;
                                      TransferHelper.safeTransfer(token1, recipient, amount1);
                                  }
                                  emit Collect(msg.sender, recipient, tickLower, tickUpper, amount0, amount1);
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              /// @dev noDelegateCall is applied indirectly via _modifyPosition
                              function burn(
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount
                              ) external override lock returns (uint256 amount0, uint256 amount1) {
                                  (Position.Info storage position, int256 amount0Int, int256 amount1Int) =
                                      _modifyPosition(
                                          ModifyPositionParams({
                                              owner: msg.sender,
                                              tickLower: tickLower,
                                              tickUpper: tickUpper,
                                              liquidityDelta: -int256(amount).toInt128()
                                          })
                                      );
                                  amount0 = uint256(-amount0Int);
                                  amount1 = uint256(-amount1Int);
                                  if (amount0 > 0 || amount1 > 0) {
                                      (position.tokensOwed0, position.tokensOwed1) = (
                                          position.tokensOwed0 + uint128(amount0),
                                          position.tokensOwed1 + uint128(amount1)
                                      );
                                  }
                                  emit Burn(msg.sender, tickLower, tickUpper, amount, amount0, amount1);
                              }
                              struct SwapCache {
                                  // the protocol fee for the input token
                                  uint8 feeProtocol;
                                  // liquidity at the beginning of the swap
                                  uint128 liquidityStart;
                                  // the timestamp of the current block
                                  uint32 blockTimestamp;
                                  // the current value of the tick accumulator, computed only if we cross an initialized tick
                                  int56 tickCumulative;
                                  // the current value of seconds per liquidity accumulator, computed only if we cross an initialized tick
                                  uint160 secondsPerLiquidityCumulativeX128;
                                  // whether we've computed and cached the above two accumulators
                                  bool computedLatestObservation;
                              }
                              // the top level state of the swap, the results of which are recorded in storage at the end
                              struct SwapState {
                                  // the amount remaining to be swapped in/out of the input/output asset
                                  int256 amountSpecifiedRemaining;
                                  // the amount already swapped out/in of the output/input asset
                                  int256 amountCalculated;
                                  // current sqrt(price)
                                  uint160 sqrtPriceX96;
                                  // the tick associated with the current price
                                  int24 tick;
                                  // the global fee growth of the input token
                                  uint256 feeGrowthGlobalX128;
                                  // amount of input token paid as protocol fee
                                  uint128 protocolFee;
                                  // the current liquidity in range
                                  uint128 liquidity;
                              }
                              struct StepComputations {
                                  // the price at the beginning of the step
                                  uint160 sqrtPriceStartX96;
                                  // the next tick to swap to from the current tick in the swap direction
                                  int24 tickNext;
                                  // whether tickNext is initialized or not
                                  bool initialized;
                                  // sqrt(price) for the next tick (1/0)
                                  uint160 sqrtPriceNextX96;
                                  // how much is being swapped in in this step
                                  uint256 amountIn;
                                  // how much is being swapped out
                                  uint256 amountOut;
                                  // how much fee is being paid in
                                  uint256 feeAmount;
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function swap(
                                  address recipient,
                                  bool zeroForOne,
                                  int256 amountSpecified,
                                  uint160 sqrtPriceLimitX96,
                                  bytes calldata data
                              ) external override noDelegateCall returns (int256 amount0, int256 amount1) {
                                  require(amountSpecified != 0, 'AS');
                                  Slot0 memory slot0Start = slot0;
                                  require(slot0Start.unlocked, 'LOK');
                                  require(
                                      zeroForOne
                                          ? sqrtPriceLimitX96 < slot0Start.sqrtPriceX96 && sqrtPriceLimitX96 > TickMath.MIN_SQRT_RATIO
                                          : sqrtPriceLimitX96 > slot0Start.sqrtPriceX96 && sqrtPriceLimitX96 < TickMath.MAX_SQRT_RATIO,
                                      'SPL'
                                  );
                                  slot0.unlocked = false;
                                  SwapCache memory cache =
                                      SwapCache({
                                          liquidityStart: liquidity,
                                          blockTimestamp: _blockTimestamp(),
                                          feeProtocol: zeroForOne ? (slot0Start.feeProtocol % 16) : (slot0Start.feeProtocol >> 4),
                                          secondsPerLiquidityCumulativeX128: 0,
                                          tickCumulative: 0,
                                          computedLatestObservation: false
                                      });
                                  bool exactInput = amountSpecified > 0;
                                  SwapState memory state =
                                      SwapState({
                                          amountSpecifiedRemaining: amountSpecified,
                                          amountCalculated: 0,
                                          sqrtPriceX96: slot0Start.sqrtPriceX96,
                                          tick: slot0Start.tick,
                                          feeGrowthGlobalX128: zeroForOne ? feeGrowthGlobal0X128 : feeGrowthGlobal1X128,
                                          protocolFee: 0,
                                          liquidity: cache.liquidityStart
                                      });
                                  // continue swapping as long as we haven't used the entire input/output and haven't reached the price limit
                                  while (state.amountSpecifiedRemaining != 0 && state.sqrtPriceX96 != sqrtPriceLimitX96) {
                                      StepComputations memory step;
                                      step.sqrtPriceStartX96 = state.sqrtPriceX96;
                                      (step.tickNext, step.initialized) = tickBitmap.nextInitializedTickWithinOneWord(
                                          state.tick,
                                          tickSpacing,
                                          zeroForOne
                                      );
                                      // ensure that we do not overshoot the min/max tick, as the tick bitmap is not aware of these bounds
                                      if (step.tickNext < TickMath.MIN_TICK) {
                                          step.tickNext = TickMath.MIN_TICK;
                                      } else if (step.tickNext > TickMath.MAX_TICK) {
                                          step.tickNext = TickMath.MAX_TICK;
                                      }
                                      // get the price for the next tick
                                      step.sqrtPriceNextX96 = TickMath.getSqrtRatioAtTick(step.tickNext);
                                      // compute values to swap to the target tick, price limit, or point where input/output amount is exhausted
                                      (state.sqrtPriceX96, step.amountIn, step.amountOut, step.feeAmount) = SwapMath.computeSwapStep(
                                          state.sqrtPriceX96,
                                          (zeroForOne ? step.sqrtPriceNextX96 < sqrtPriceLimitX96 : step.sqrtPriceNextX96 > sqrtPriceLimitX96)
                                              ? sqrtPriceLimitX96
                                              : step.sqrtPriceNextX96,
                                          state.liquidity,
                                          state.amountSpecifiedRemaining,
                                          fee
                                      );
                                      if (exactInput) {
                                          state.amountSpecifiedRemaining -= (step.amountIn + step.feeAmount).toInt256();
                                          state.amountCalculated = state.amountCalculated.sub(step.amountOut.toInt256());
                                      } else {
                                          state.amountSpecifiedRemaining += step.amountOut.toInt256();
                                          state.amountCalculated = state.amountCalculated.add((step.amountIn + step.feeAmount).toInt256());
                                      }
                                      // if the protocol fee is on, calculate how much is owed, decrement feeAmount, and increment protocolFee
                                      if (cache.feeProtocol > 0) {
                                          uint256 delta = step.feeAmount / cache.feeProtocol;
                                          step.feeAmount -= delta;
                                          state.protocolFee += uint128(delta);
                                      }
                                      // update global fee tracker
                                      if (state.liquidity > 0)
                                          state.feeGrowthGlobalX128 += FullMath.mulDiv(step.feeAmount, FixedPoint128.Q128, state.liquidity);
                                      // shift tick if we reached the next price
                                      if (state.sqrtPriceX96 == step.sqrtPriceNextX96) {
                                          // if the tick is initialized, run the tick transition
                                          if (step.initialized) {
                                              // check for the placeholder value, which we replace with the actual value the first time the swap
                                              // crosses an initialized tick
                                              if (!cache.computedLatestObservation) {
                                                  (cache.tickCumulative, cache.secondsPerLiquidityCumulativeX128) = observations.observeSingle(
                                                      cache.blockTimestamp,
                                                      0,
                                                      slot0Start.tick,
                                                      slot0Start.observationIndex,
                                                      cache.liquidityStart,
                                                      slot0Start.observationCardinality
                                                  );
                                                  cache.computedLatestObservation = true;
                                              }
                                              int128 liquidityNet =
                                                  ticks.cross(
                                                      step.tickNext,
                                                      (zeroForOne ? state.feeGrowthGlobalX128 : feeGrowthGlobal0X128),
                                                      (zeroForOne ? feeGrowthGlobal1X128 : state.feeGrowthGlobalX128),
                                                      cache.secondsPerLiquidityCumulativeX128,
                                                      cache.tickCumulative,
                                                      cache.blockTimestamp
                                                  );
                                              // if we're moving leftward, we interpret liquidityNet as the opposite sign
                                              // safe because liquidityNet cannot be type(int128).min
                                              if (zeroForOne) liquidityNet = -liquidityNet;
                                              state.liquidity = LiquidityMath.addDelta(state.liquidity, liquidityNet);
                                          }
                                          state.tick = zeroForOne ? step.tickNext - 1 : step.tickNext;
                                      } else if (state.sqrtPriceX96 != step.sqrtPriceStartX96) {
                                          // recompute unless we're on a lower tick boundary (i.e. already transitioned ticks), and haven't moved
                                          state.tick = TickMath.getTickAtSqrtRatio(state.sqrtPriceX96);
                                      }
                                  }
                                  // update tick and write an oracle entry if the tick change
                                  if (state.tick != slot0Start.tick) {
                                      (uint16 observationIndex, uint16 observationCardinality) =
                                          observations.write(
                                              slot0Start.observationIndex,
                                              cache.blockTimestamp,
                                              slot0Start.tick,
                                              cache.liquidityStart,
                                              slot0Start.observationCardinality,
                                              slot0Start.observationCardinalityNext
                                          );
                                      (slot0.sqrtPriceX96, slot0.tick, slot0.observationIndex, slot0.observationCardinality) = (
                                          state.sqrtPriceX96,
                                          state.tick,
                                          observationIndex,
                                          observationCardinality
                                      );
                                  } else {
                                      // otherwise just update the price
                                      slot0.sqrtPriceX96 = state.sqrtPriceX96;
                                  }
                                  // update liquidity if it changed
                                  if (cache.liquidityStart != state.liquidity) liquidity = state.liquidity;
                                  // update fee growth global and, if necessary, protocol fees
                                  // overflow is acceptable, protocol has to withdraw before it hits type(uint128).max fees
                                  if (zeroForOne) {
                                      feeGrowthGlobal0X128 = state.feeGrowthGlobalX128;
                                      if (state.protocolFee > 0) protocolFees.token0 += state.protocolFee;
                                  } else {
                                      feeGrowthGlobal1X128 = state.feeGrowthGlobalX128;
                                      if (state.protocolFee > 0) protocolFees.token1 += state.protocolFee;
                                  }
                                  (amount0, amount1) = zeroForOne == exactInput
                                      ? (amountSpecified - state.amountSpecifiedRemaining, state.amountCalculated)
                                      : (state.amountCalculated, amountSpecified - state.amountSpecifiedRemaining);
                                  // do the transfers and collect payment
                                  if (zeroForOne) {
                                      if (amount1 < 0) TransferHelper.safeTransfer(token1, recipient, uint256(-amount1));
                                      uint256 balance0Before = balance0();
                                      IUniswapV3SwapCallback(msg.sender).uniswapV3SwapCallback(amount0, amount1, data);
                                      require(balance0Before.add(uint256(amount0)) <= balance0(), 'IIA');
                                  } else {
                                      if (amount0 < 0) TransferHelper.safeTransfer(token0, recipient, uint256(-amount0));
                                      uint256 balance1Before = balance1();
                                      IUniswapV3SwapCallback(msg.sender).uniswapV3SwapCallback(amount0, amount1, data);
                                      require(balance1Before.add(uint256(amount1)) <= balance1(), 'IIA');
                                  }
                                  emit Swap(msg.sender, recipient, amount0, amount1, state.sqrtPriceX96, state.liquidity, state.tick);
                                  slot0.unlocked = true;
                              }
                              /// @inheritdoc IUniswapV3PoolActions
                              function flash(
                                  address recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  bytes calldata data
                              ) external override lock noDelegateCall {
                                  uint128 _liquidity = liquidity;
                                  require(_liquidity > 0, 'L');
                                  uint256 fee0 = FullMath.mulDivRoundingUp(amount0, fee, 1e6);
                                  uint256 fee1 = FullMath.mulDivRoundingUp(amount1, fee, 1e6);
                                  uint256 balance0Before = balance0();
                                  uint256 balance1Before = balance1();
                                  if (amount0 > 0) TransferHelper.safeTransfer(token0, recipient, amount0);
                                  if (amount1 > 0) TransferHelper.safeTransfer(token1, recipient, amount1);
                                  IUniswapV3FlashCallback(msg.sender).uniswapV3FlashCallback(fee0, fee1, data);
                                  uint256 balance0After = balance0();
                                  uint256 balance1After = balance1();
                                  require(balance0Before.add(fee0) <= balance0After, 'F0');
                                  require(balance1Before.add(fee1) <= balance1After, 'F1');
                                  // sub is safe because we know balanceAfter is gt balanceBefore by at least fee
                                  uint256 paid0 = balance0After - balance0Before;
                                  uint256 paid1 = balance1After - balance1Before;
                                  if (paid0 > 0) {
                                      uint8 feeProtocol0 = slot0.feeProtocol % 16;
                                      uint256 fees0 = feeProtocol0 == 0 ? 0 : paid0 / feeProtocol0;
                                      if (uint128(fees0) > 0) protocolFees.token0 += uint128(fees0);
                                      feeGrowthGlobal0X128 += FullMath.mulDiv(paid0 - fees0, FixedPoint128.Q128, _liquidity);
                                  }
                                  if (paid1 > 0) {
                                      uint8 feeProtocol1 = slot0.feeProtocol >> 4;
                                      uint256 fees1 = feeProtocol1 == 0 ? 0 : paid1 / feeProtocol1;
                                      if (uint128(fees1) > 0) protocolFees.token1 += uint128(fees1);
                                      feeGrowthGlobal1X128 += FullMath.mulDiv(paid1 - fees1, FixedPoint128.Q128, _liquidity);
                                  }
                                  emit Flash(msg.sender, recipient, amount0, amount1, paid0, paid1);
                              }
                              /// @inheritdoc IUniswapV3PoolOwnerActions
                              function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external override lock onlyFactoryOwner {
                                  require(
                                      (feeProtocol0 == 0 || (feeProtocol0 >= 4 && feeProtocol0 <= 10)) &&
                                          (feeProtocol1 == 0 || (feeProtocol1 >= 4 && feeProtocol1 <= 10))
                                  );
                                  uint8 feeProtocolOld = slot0.feeProtocol;
                                  slot0.feeProtocol = feeProtocol0 + (feeProtocol1 << 4);
                                  emit SetFeeProtocol(feeProtocolOld % 16, feeProtocolOld >> 4, feeProtocol0, feeProtocol1);
                              }
                              /// @inheritdoc IUniswapV3PoolOwnerActions
                              function collectProtocol(
                                  address recipient,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external override lock onlyFactoryOwner returns (uint128 amount0, uint128 amount1) {
                                  amount0 = amount0Requested > protocolFees.token0 ? protocolFees.token0 : amount0Requested;
                                  amount1 = amount1Requested > protocolFees.token1 ? protocolFees.token1 : amount1Requested;
                                  if (amount0 > 0) {
                                      if (amount0 == protocolFees.token0) amount0--; // ensure that the slot is not cleared, for gas savings
                                      protocolFees.token0 -= amount0;
                                      TransferHelper.safeTransfer(token0, recipient, amount0);
                                  }
                                  if (amount1 > 0) {
                                      if (amount1 == protocolFees.token1) amount1--; // ensure that the slot is not cleared, for gas savings
                                      protocolFees.token1 -= amount1;
                                      TransferHelper.safeTransfer(token1, recipient, amount1);
                                  }
                                  emit CollectProtocol(msg.sender, recipient, amount0, amount1);
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          import './pool/IUniswapV3PoolImmutables.sol';
                          import './pool/IUniswapV3PoolState.sol';
                          import './pool/IUniswapV3PoolDerivedState.sol';
                          import './pool/IUniswapV3PoolActions.sol';
                          import './pool/IUniswapV3PoolOwnerActions.sol';
                          import './pool/IUniswapV3PoolEvents.sol';
                          /// @title The interface for a Uniswap V3 Pool
                          /// @notice A Uniswap pool facilitates swapping and automated market making between any two assets that strictly conform
                          /// to the ERC20 specification
                          /// @dev The pool interface is broken up into many smaller pieces
                          interface IUniswapV3Pool is
                              IUniswapV3PoolImmutables,
                              IUniswapV3PoolState,
                              IUniswapV3PoolDerivedState,
                              IUniswapV3PoolActions,
                              IUniswapV3PoolOwnerActions,
                              IUniswapV3PoolEvents
                          {
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity =0.7.6;
                          /// @title Prevents delegatecall to a contract
                          /// @notice Base contract that provides a modifier for preventing delegatecall to methods in a child contract
                          abstract contract NoDelegateCall {
                              /// @dev The original address of this contract
                              address private immutable original;
                              constructor() {
                                  // Immutables are computed in the init code of the contract, and then inlined into the deployed bytecode.
                                  // In other words, this variable won't change when it's checked at runtime.
                                  original = address(this);
                              }
                              /// @dev Private method is used instead of inlining into modifier because modifiers are copied into each method,
                              ///     and the use of immutable means the address bytes are copied in every place the modifier is used.
                              function checkNotDelegateCall() private view {
                                  require(address(this) == original);
                              }
                              /// @notice Prevents delegatecall into the modified method
                              modifier noDelegateCall() {
                                  checkNotDelegateCall();
                                  _;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.7.0;
                          /// @title Optimized overflow and underflow safe math operations
                          /// @notice Contains methods for doing math operations that revert on overflow or underflow for minimal gas cost
                          library LowGasSafeMath {
                              /// @notice Returns x + y, reverts if sum overflows uint256
                              /// @param x The augend
                              /// @param y The addend
                              /// @return z The sum of x and y
                              function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require((z = x + y) >= x);
                              }
                              /// @notice Returns x - y, reverts if underflows
                              /// @param x The minuend
                              /// @param y The subtrahend
                              /// @return z The difference of x and y
                              function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require((z = x - y) <= x);
                              }
                              /// @notice Returns x * y, reverts if overflows
                              /// @param x The multiplicand
                              /// @param y The multiplier
                              /// @return z The product of x and y
                              function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  require(x == 0 || (z = x * y) / x == y);
                              }
                              /// @notice Returns x + y, reverts if overflows or underflows
                              /// @param x The augend
                              /// @param y The addend
                              /// @return z The sum of x and y
                              function add(int256 x, int256 y) internal pure returns (int256 z) {
                                  require((z = x + y) >= x == (y >= 0));
                              }
                              /// @notice Returns x - y, reverts if overflows or underflows
                              /// @param x The minuend
                              /// @param y The subtrahend
                              /// @return z The difference of x and y
                              function sub(int256 x, int256 y) internal pure returns (int256 z) {
                                  require((z = x - y) <= x == (y >= 0));
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Safe casting methods
                          /// @notice Contains methods for safely casting between types
                          library SafeCast {
                              /// @notice Cast a uint256 to a uint160, revert on overflow
                              /// @param y The uint256 to be downcasted
                              /// @return z The downcasted integer, now type uint160
                              function toUint160(uint256 y) internal pure returns (uint160 z) {
                                  require((z = uint160(y)) == y);
                              }
                              /// @notice Cast a int256 to a int128, revert on overflow or underflow
                              /// @param y The int256 to be downcasted
                              /// @return z The downcasted integer, now type int128
                              function toInt128(int256 y) internal pure returns (int128 z) {
                                  require((z = int128(y)) == y);
                              }
                              /// @notice Cast a uint256 to a int256, revert on overflow
                              /// @param y The uint256 to be casted
                              /// @return z The casted integer, now type int256
                              function toInt256(uint256 y) internal pure returns (int256 z) {
                                  require(y < 2**255);
                                  z = int256(y);
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './LowGasSafeMath.sol';
                          import './SafeCast.sol';
                          import './TickMath.sol';
                          import './LiquidityMath.sol';
                          /// @title Tick
                          /// @notice Contains functions for managing tick processes and relevant calculations
                          library Tick {
                              using LowGasSafeMath for int256;
                              using SafeCast for int256;
                              // info stored for each initialized individual tick
                              struct Info {
                                  // the total position liquidity that references this tick
                                  uint128 liquidityGross;
                                  // amount of net liquidity added (subtracted) when tick is crossed from left to right (right to left),
                                  int128 liquidityNet;
                                  // fee growth per unit of liquidity on the _other_ side of this tick (relative to the current tick)
                                  // only has relative meaning, not absolute — the value depends on when the tick is initialized
                                  uint256 feeGrowthOutside0X128;
                                  uint256 feeGrowthOutside1X128;
                                  // the cumulative tick value on the other side of the tick
                                  int56 tickCumulativeOutside;
                                  // the seconds per unit of liquidity on the _other_ side of this tick (relative to the current tick)
                                  // only has relative meaning, not absolute — the value depends on when the tick is initialized
                                  uint160 secondsPerLiquidityOutsideX128;
                                  // the seconds spent on the other side of the tick (relative to the current tick)
                                  // only has relative meaning, not absolute — the value depends on when the tick is initialized
                                  uint32 secondsOutside;
                                  // true iff the tick is initialized, i.e. the value is exactly equivalent to the expression liquidityGross != 0
                                  // these 8 bits are set to prevent fresh sstores when crossing newly initialized ticks
                                  bool initialized;
                              }
                              /// @notice Derives max liquidity per tick from given tick spacing
                              /// @dev Executed within the pool constructor
                              /// @param tickSpacing The amount of required tick separation, realized in multiples of `tickSpacing`
                              ///     e.g., a tickSpacing of 3 requires ticks to be initialized every 3rd tick i.e., ..., -6, -3, 0, 3, 6, ...
                              /// @return The max liquidity per tick
                              function tickSpacingToMaxLiquidityPerTick(int24 tickSpacing) internal pure returns (uint128) {
                                  int24 minTick = (TickMath.MIN_TICK / tickSpacing) * tickSpacing;
                                  int24 maxTick = (TickMath.MAX_TICK / tickSpacing) * tickSpacing;
                                  uint24 numTicks = uint24((maxTick - minTick) / tickSpacing) + 1;
                                  return type(uint128).max / numTicks;
                              }
                              /// @notice Retrieves fee growth data
                              /// @param self The mapping containing all tick information for initialized ticks
                              /// @param tickLower The lower tick boundary of the position
                              /// @param tickUpper The upper tick boundary of the position
                              /// @param tickCurrent The current tick
                              /// @param feeGrowthGlobal0X128 The all-time global fee growth, per unit of liquidity, in token0
                              /// @param feeGrowthGlobal1X128 The all-time global fee growth, per unit of liquidity, in token1
                              /// @return feeGrowthInside0X128 The all-time fee growth in token0, per unit of liquidity, inside the position's tick boundaries
                              /// @return feeGrowthInside1X128 The all-time fee growth in token1, per unit of liquidity, inside the position's tick boundaries
                              function getFeeGrowthInside(
                                  mapping(int24 => Tick.Info) storage self,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  int24 tickCurrent,
                                  uint256 feeGrowthGlobal0X128,
                                  uint256 feeGrowthGlobal1X128
                              ) internal view returns (uint256 feeGrowthInside0X128, uint256 feeGrowthInside1X128) {
                                  Info storage lower = self[tickLower];
                                  Info storage upper = self[tickUpper];
                                  // calculate fee growth below
                                  uint256 feeGrowthBelow0X128;
                                  uint256 feeGrowthBelow1X128;
                                  if (tickCurrent >= tickLower) {
                                      feeGrowthBelow0X128 = lower.feeGrowthOutside0X128;
                                      feeGrowthBelow1X128 = lower.feeGrowthOutside1X128;
                                  } else {
                                      feeGrowthBelow0X128 = feeGrowthGlobal0X128 - lower.feeGrowthOutside0X128;
                                      feeGrowthBelow1X128 = feeGrowthGlobal1X128 - lower.feeGrowthOutside1X128;
                                  }
                                  // calculate fee growth above
                                  uint256 feeGrowthAbove0X128;
                                  uint256 feeGrowthAbove1X128;
                                  if (tickCurrent < tickUpper) {
                                      feeGrowthAbove0X128 = upper.feeGrowthOutside0X128;
                                      feeGrowthAbove1X128 = upper.feeGrowthOutside1X128;
                                  } else {
                                      feeGrowthAbove0X128 = feeGrowthGlobal0X128 - upper.feeGrowthOutside0X128;
                                      feeGrowthAbove1X128 = feeGrowthGlobal1X128 - upper.feeGrowthOutside1X128;
                                  }
                                  feeGrowthInside0X128 = feeGrowthGlobal0X128 - feeGrowthBelow0X128 - feeGrowthAbove0X128;
                                  feeGrowthInside1X128 = feeGrowthGlobal1X128 - feeGrowthBelow1X128 - feeGrowthAbove1X128;
                              }
                              /// @notice Updates a tick and returns true if the tick was flipped from initialized to uninitialized, or vice versa
                              /// @param self The mapping containing all tick information for initialized ticks
                              /// @param tick The tick that will be updated
                              /// @param tickCurrent The current tick
                              /// @param liquidityDelta A new amount of liquidity to be added (subtracted) when tick is crossed from left to right (right to left)
                              /// @param feeGrowthGlobal0X128 The all-time global fee growth, per unit of liquidity, in token0
                              /// @param feeGrowthGlobal1X128 The all-time global fee growth, per unit of liquidity, in token1
                              /// @param secondsPerLiquidityCumulativeX128 The all-time seconds per max(1, liquidity) of the pool
                              /// @param time The current block timestamp cast to a uint32
                              /// @param upper true for updating a position's upper tick, or false for updating a position's lower tick
                              /// @param maxLiquidity The maximum liquidity allocation for a single tick
                              /// @return flipped Whether the tick was flipped from initialized to uninitialized, or vice versa
                              function update(
                                  mapping(int24 => Tick.Info) storage self,
                                  int24 tick,
                                  int24 tickCurrent,
                                  int128 liquidityDelta,
                                  uint256 feeGrowthGlobal0X128,
                                  uint256 feeGrowthGlobal1X128,
                                  uint160 secondsPerLiquidityCumulativeX128,
                                  int56 tickCumulative,
                                  uint32 time,
                                  bool upper,
                                  uint128 maxLiquidity
                              ) internal returns (bool flipped) {
                                  Tick.Info storage info = self[tick];
                                  uint128 liquidityGrossBefore = info.liquidityGross;
                                  uint128 liquidityGrossAfter = LiquidityMath.addDelta(liquidityGrossBefore, liquidityDelta);
                                  require(liquidityGrossAfter <= maxLiquidity, 'LO');
                                  flipped = (liquidityGrossAfter == 0) != (liquidityGrossBefore == 0);
                                  if (liquidityGrossBefore == 0) {
                                      // by convention, we assume that all growth before a tick was initialized happened _below_ the tick
                                      if (tick <= tickCurrent) {
                                          info.feeGrowthOutside0X128 = feeGrowthGlobal0X128;
                                          info.feeGrowthOutside1X128 = feeGrowthGlobal1X128;
                                          info.secondsPerLiquidityOutsideX128 = secondsPerLiquidityCumulativeX128;
                                          info.tickCumulativeOutside = tickCumulative;
                                          info.secondsOutside = time;
                                      }
                                      info.initialized = true;
                                  }
                                  info.liquidityGross = liquidityGrossAfter;
                                  // when the lower (upper) tick is crossed left to right (right to left), liquidity must be added (removed)
                                  info.liquidityNet = upper
                                      ? int256(info.liquidityNet).sub(liquidityDelta).toInt128()
                                      : int256(info.liquidityNet).add(liquidityDelta).toInt128();
                              }
                              /// @notice Clears tick data
                              /// @param self The mapping containing all initialized tick information for initialized ticks
                              /// @param tick The tick that will be cleared
                              function clear(mapping(int24 => Tick.Info) storage self, int24 tick) internal {
                                  delete self[tick];
                              }
                              /// @notice Transitions to next tick as needed by price movement
                              /// @param self The mapping containing all tick information for initialized ticks
                              /// @param tick The destination tick of the transition
                              /// @param feeGrowthGlobal0X128 The all-time global fee growth, per unit of liquidity, in token0
                              /// @param feeGrowthGlobal1X128 The all-time global fee growth, per unit of liquidity, in token1
                              /// @param secondsPerLiquidityCumulativeX128 The current seconds per liquidity
                              /// @param time The current block.timestamp
                              /// @return liquidityNet The amount of liquidity added (subtracted) when tick is crossed from left to right (right to left)
                              function cross(
                                  mapping(int24 => Tick.Info) storage self,
                                  int24 tick,
                                  uint256 feeGrowthGlobal0X128,
                                  uint256 feeGrowthGlobal1X128,
                                  uint160 secondsPerLiquidityCumulativeX128,
                                  int56 tickCumulative,
                                  uint32 time
                              ) internal returns (int128 liquidityNet) {
                                  Tick.Info storage info = self[tick];
                                  info.feeGrowthOutside0X128 = feeGrowthGlobal0X128 - info.feeGrowthOutside0X128;
                                  info.feeGrowthOutside1X128 = feeGrowthGlobal1X128 - info.feeGrowthOutside1X128;
                                  info.secondsPerLiquidityOutsideX128 = secondsPerLiquidityCumulativeX128 - info.secondsPerLiquidityOutsideX128;
                                  info.tickCumulativeOutside = tickCumulative - info.tickCumulativeOutside;
                                  info.secondsOutside = time - info.secondsOutside;
                                  liquidityNet = info.liquidityNet;
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './BitMath.sol';
                          /// @title Packed tick initialized state library
                          /// @notice Stores a packed mapping of tick index to its initialized state
                          /// @dev The mapping uses int16 for keys since ticks are represented as int24 and there are 256 (2^8) values per word.
                          library TickBitmap {
                              /// @notice Computes the position in the mapping where the initialized bit for a tick lives
                              /// @param tick The tick for which to compute the position
                              /// @return wordPos The key in the mapping containing the word in which the bit is stored
                              /// @return bitPos The bit position in the word where the flag is stored
                              function position(int24 tick) private pure returns (int16 wordPos, uint8 bitPos) {
                                  wordPos = int16(tick >> 8);
                                  bitPos = uint8(tick % 256);
                              }
                              /// @notice Flips the initialized state for a given tick from false to true, or vice versa
                              /// @param self The mapping in which to flip the tick
                              /// @param tick The tick to flip
                              /// @param tickSpacing The spacing between usable ticks
                              function flipTick(
                                  mapping(int16 => uint256) storage self,
                                  int24 tick,
                                  int24 tickSpacing
                              ) internal {
                                  require(tick % tickSpacing == 0); // ensure that the tick is spaced
                                  (int16 wordPos, uint8 bitPos) = position(tick / tickSpacing);
                                  uint256 mask = 1 << bitPos;
                                  self[wordPos] ^= mask;
                              }
                              /// @notice Returns the next initialized tick contained in the same word (or adjacent word) as the tick that is either
                              /// to the left (less than or equal to) or right (greater than) of the given tick
                              /// @param self The mapping in which to compute the next initialized tick
                              /// @param tick The starting tick
                              /// @param tickSpacing The spacing between usable ticks
                              /// @param lte Whether to search for the next initialized tick to the left (less than or equal to the starting tick)
                              /// @return next The next initialized or uninitialized tick up to 256 ticks away from the current tick
                              /// @return initialized Whether the next tick is initialized, as the function only searches within up to 256 ticks
                              function nextInitializedTickWithinOneWord(
                                  mapping(int16 => uint256) storage self,
                                  int24 tick,
                                  int24 tickSpacing,
                                  bool lte
                              ) internal view returns (int24 next, bool initialized) {
                                  int24 compressed = tick / tickSpacing;
                                  if (tick < 0 && tick % tickSpacing != 0) compressed--; // round towards negative infinity
                                  if (lte) {
                                      (int16 wordPos, uint8 bitPos) = position(compressed);
                                      // all the 1s at or to the right of the current bitPos
                                      uint256 mask = (1 << bitPos) - 1 + (1 << bitPos);
                                      uint256 masked = self[wordPos] & mask;
                                      // if there are no initialized ticks to the right of or at the current tick, return rightmost in the word
                                      initialized = masked != 0;
                                      // overflow/underflow is possible, but prevented externally by limiting both tickSpacing and tick
                                      next = initialized
                                          ? (compressed - int24(bitPos - BitMath.mostSignificantBit(masked))) * tickSpacing
                                          : (compressed - int24(bitPos)) * tickSpacing;
                                  } else {
                                      // start from the word of the next tick, since the current tick state doesn't matter
                                      (int16 wordPos, uint8 bitPos) = position(compressed + 1);
                                      // all the 1s at or to the left of the bitPos
                                      uint256 mask = ~((1 << bitPos) - 1);
                                      uint256 masked = self[wordPos] & mask;
                                      // if there are no initialized ticks to the left of the current tick, return leftmost in the word
                                      initialized = masked != 0;
                                      // overflow/underflow is possible, but prevented externally by limiting both tickSpacing and tick
                                      next = initialized
                                          ? (compressed + 1 + int24(BitMath.leastSignificantBit(masked) - bitPos)) * tickSpacing
                                          : (compressed + 1 + int24(type(uint8).max - bitPos)) * tickSpacing;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './FullMath.sol';
                          import './FixedPoint128.sol';
                          import './LiquidityMath.sol';
                          /// @title Position
                          /// @notice Positions represent an owner address' liquidity between a lower and upper tick boundary
                          /// @dev Positions store additional state for tracking fees owed to the position
                          library Position {
                              // info stored for each user's position
                              struct Info {
                                  // the amount of liquidity owned by this position
                                  uint128 liquidity;
                                  // fee growth per unit of liquidity as of the last update to liquidity or fees owed
                                  uint256 feeGrowthInside0LastX128;
                                  uint256 feeGrowthInside1LastX128;
                                  // the fees owed to the position owner in token0/token1
                                  uint128 tokensOwed0;
                                  uint128 tokensOwed1;
                              }
                              /// @notice Returns the Info struct of a position, given an owner and position boundaries
                              /// @param self The mapping containing all user positions
                              /// @param owner The address of the position owner
                              /// @param tickLower The lower tick boundary of the position
                              /// @param tickUpper The upper tick boundary of the position
                              /// @return position The position info struct of the given owners' position
                              function get(
                                  mapping(bytes32 => Info) storage self,
                                  address owner,
                                  int24 tickLower,
                                  int24 tickUpper
                              ) internal view returns (Position.Info storage position) {
                                  position = self[keccak256(abi.encodePacked(owner, tickLower, tickUpper))];
                              }
                              /// @notice Credits accumulated fees to a user's position
                              /// @param self The individual position to update
                              /// @param liquidityDelta The change in pool liquidity as a result of the position update
                              /// @param feeGrowthInside0X128 The all-time fee growth in token0, per unit of liquidity, inside the position's tick boundaries
                              /// @param feeGrowthInside1X128 The all-time fee growth in token1, per unit of liquidity, inside the position's tick boundaries
                              function update(
                                  Info storage self,
                                  int128 liquidityDelta,
                                  uint256 feeGrowthInside0X128,
                                  uint256 feeGrowthInside1X128
                              ) internal {
                                  Info memory _self = self;
                                  uint128 liquidityNext;
                                  if (liquidityDelta == 0) {
                                      require(_self.liquidity > 0, 'NP'); // disallow pokes for 0 liquidity positions
                                      liquidityNext = _self.liquidity;
                                  } else {
                                      liquidityNext = LiquidityMath.addDelta(_self.liquidity, liquidityDelta);
                                  }
                                  // calculate accumulated fees
                                  uint128 tokensOwed0 =
                                      uint128(
                                          FullMath.mulDiv(
                                              feeGrowthInside0X128 - _self.feeGrowthInside0LastX128,
                                              _self.liquidity,
                                              FixedPoint128.Q128
                                          )
                                      );
                                  uint128 tokensOwed1 =
                                      uint128(
                                          FullMath.mulDiv(
                                              feeGrowthInside1X128 - _self.feeGrowthInside1LastX128,
                                              _self.liquidity,
                                              FixedPoint128.Q128
                                          )
                                      );
                                  // update the position
                                  if (liquidityDelta != 0) self.liquidity = liquidityNext;
                                  self.feeGrowthInside0LastX128 = feeGrowthInside0X128;
                                  self.feeGrowthInside1LastX128 = feeGrowthInside1X128;
                                  if (tokensOwed0 > 0 || tokensOwed1 > 0) {
                                      // overflow is acceptable, have to withdraw before you hit type(uint128).max fees
                                      self.tokensOwed0 += tokensOwed0;
                                      self.tokensOwed1 += tokensOwed1;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          /// @title Oracle
                          /// @notice Provides price and liquidity data useful for a wide variety of system designs
                          /// @dev Instances of stored oracle data, "observations", are collected in the oracle array
                          /// Every pool is initialized with an oracle array length of 1. Anyone can pay the SSTOREs to increase the
                          /// maximum length of the oracle array. New slots will be added when the array is fully populated.
                          /// Observations are overwritten when the full length of the oracle array is populated.
                          /// The most recent observation is available, independent of the length of the oracle array, by passing 0 to observe()
                          library Oracle {
                              struct Observation {
                                  // the block timestamp of the observation
                                  uint32 blockTimestamp;
                                  // the tick accumulator, i.e. tick * time elapsed since the pool was first initialized
                                  int56 tickCumulative;
                                  // the seconds per liquidity, i.e. seconds elapsed / max(1, liquidity) since the pool was first initialized
                                  uint160 secondsPerLiquidityCumulativeX128;
                                  // whether or not the observation is initialized
                                  bool initialized;
                              }
                              /// @notice Transforms a previous observation into a new observation, given the passage of time and the current tick and liquidity values
                              /// @dev blockTimestamp _must_ be chronologically equal to or greater than last.blockTimestamp, safe for 0 or 1 overflows
                              /// @param last The specified observation to be transformed
                              /// @param blockTimestamp The timestamp of the new observation
                              /// @param tick The active tick at the time of the new observation
                              /// @param liquidity The total in-range liquidity at the time of the new observation
                              /// @return Observation The newly populated observation
                              function transform(
                                  Observation memory last,
                                  uint32 blockTimestamp,
                                  int24 tick,
                                  uint128 liquidity
                              ) private pure returns (Observation memory) {
                                  uint32 delta = blockTimestamp - last.blockTimestamp;
                                  return
                                      Observation({
                                          blockTimestamp: blockTimestamp,
                                          tickCumulative: last.tickCumulative + int56(tick) * delta,
                                          secondsPerLiquidityCumulativeX128: last.secondsPerLiquidityCumulativeX128 +
                                              ((uint160(delta) << 128) / (liquidity > 0 ? liquidity : 1)),
                                          initialized: true
                                      });
                              }
                              /// @notice Initialize the oracle array by writing the first slot. Called once for the lifecycle of the observations array
                              /// @param self The stored oracle array
                              /// @param time The time of the oracle initialization, via block.timestamp truncated to uint32
                              /// @return cardinality The number of populated elements in the oracle array
                              /// @return cardinalityNext The new length of the oracle array, independent of population
                              function initialize(Observation[65535] storage self, uint32 time)
                                  internal
                                  returns (uint16 cardinality, uint16 cardinalityNext)
                              {
                                  self[0] = Observation({
                                      blockTimestamp: time,
                                      tickCumulative: 0,
                                      secondsPerLiquidityCumulativeX128: 0,
                                      initialized: true
                                  });
                                  return (1, 1);
                              }
                              /// @notice Writes an oracle observation to the array
                              /// @dev Writable at most once per block. Index represents the most recently written element. cardinality and index must be tracked externally.
                              /// If the index is at the end of the allowable array length (according to cardinality), and the next cardinality
                              /// is greater than the current one, cardinality may be increased. This restriction is created to preserve ordering.
                              /// @param self The stored oracle array
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param blockTimestamp The timestamp of the new observation
                              /// @param tick The active tick at the time of the new observation
                              /// @param liquidity The total in-range liquidity at the time of the new observation
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @param cardinalityNext The new length of the oracle array, independent of population
                              /// @return indexUpdated The new index of the most recently written element in the oracle array
                              /// @return cardinalityUpdated The new cardinality of the oracle array
                              function write(
                                  Observation[65535] storage self,
                                  uint16 index,
                                  uint32 blockTimestamp,
                                  int24 tick,
                                  uint128 liquidity,
                                  uint16 cardinality,
                                  uint16 cardinalityNext
                              ) internal returns (uint16 indexUpdated, uint16 cardinalityUpdated) {
                                  Observation memory last = self[index];
                                  // early return if we've already written an observation this block
                                  if (last.blockTimestamp == blockTimestamp) return (index, cardinality);
                                  // if the conditions are right, we can bump the cardinality
                                  if (cardinalityNext > cardinality && index == (cardinality - 1)) {
                                      cardinalityUpdated = cardinalityNext;
                                  } else {
                                      cardinalityUpdated = cardinality;
                                  }
                                  indexUpdated = (index + 1) % cardinalityUpdated;
                                  self[indexUpdated] = transform(last, blockTimestamp, tick, liquidity);
                              }
                              /// @notice Prepares the oracle array to store up to `next` observations
                              /// @param self The stored oracle array
                              /// @param current The current next cardinality of the oracle array
                              /// @param next The proposed next cardinality which will be populated in the oracle array
                              /// @return next The next cardinality which will be populated in the oracle array
                              function grow(
                                  Observation[65535] storage self,
                                  uint16 current,
                                  uint16 next
                              ) internal returns (uint16) {
                                  require(current > 0, 'I');
                                  // no-op if the passed next value isn't greater than the current next value
                                  if (next <= current) return current;
                                  // store in each slot to prevent fresh SSTOREs in swaps
                                  // this data will not be used because the initialized boolean is still false
                                  for (uint16 i = current; i < next; i++) self[i].blockTimestamp = 1;
                                  return next;
                              }
                              /// @notice comparator for 32-bit timestamps
                              /// @dev safe for 0 or 1 overflows, a and b _must_ be chronologically before or equal to time
                              /// @param time A timestamp truncated to 32 bits
                              /// @param a A comparison timestamp from which to determine the relative position of `time`
                              /// @param b From which to determine the relative position of `time`
                              /// @return bool Whether `a` is chronologically <= `b`
                              function lte(
                                  uint32 time,
                                  uint32 a,
                                  uint32 b
                              ) private pure returns (bool) {
                                  // if there hasn't been overflow, no need to adjust
                                  if (a <= time && b <= time) return a <= b;
                                  uint256 aAdjusted = a > time ? a : a + 2**32;
                                  uint256 bAdjusted = b > time ? b : b + 2**32;
                                  return aAdjusted <= bAdjusted;
                              }
                              /// @notice Fetches the observations beforeOrAt and atOrAfter a target, i.e. where [beforeOrAt, atOrAfter] is satisfied.
                              /// The result may be the same observation, or adjacent observations.
                              /// @dev The answer must be contained in the array, used when the target is located within the stored observation
                              /// boundaries: older than the most recent observation and younger, or the same age as, the oldest observation
                              /// @param self The stored oracle array
                              /// @param time The current block.timestamp
                              /// @param target The timestamp at which the reserved observation should be for
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return beforeOrAt The observation recorded before, or at, the target
                              /// @return atOrAfter The observation recorded at, or after, the target
                              function binarySearch(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32 target,
                                  uint16 index,
                                  uint16 cardinality
                              ) private view returns (Observation memory beforeOrAt, Observation memory atOrAfter) {
                                  uint256 l = (index + 1) % cardinality; // oldest observation
                                  uint256 r = l + cardinality - 1; // newest observation
                                  uint256 i;
                                  while (true) {
                                      i = (l + r) / 2;
                                      beforeOrAt = self[i % cardinality];
                                      // we've landed on an uninitialized tick, keep searching higher (more recently)
                                      if (!beforeOrAt.initialized) {
                                          l = i + 1;
                                          continue;
                                      }
                                      atOrAfter = self[(i + 1) % cardinality];
                                      bool targetAtOrAfter = lte(time, beforeOrAt.blockTimestamp, target);
                                      // check if we've found the answer!
                                      if (targetAtOrAfter && lte(time, target, atOrAfter.blockTimestamp)) break;
                                      if (!targetAtOrAfter) r = i - 1;
                                      else l = i + 1;
                                  }
                              }
                              /// @notice Fetches the observations beforeOrAt and atOrAfter a given target, i.e. where [beforeOrAt, atOrAfter] is satisfied
                              /// @dev Assumes there is at least 1 initialized observation.
                              /// Used by observeSingle() to compute the counterfactual accumulator values as of a given block timestamp.
                              /// @param self The stored oracle array
                              /// @param time The current block.timestamp
                              /// @param target The timestamp at which the reserved observation should be for
                              /// @param tick The active tick at the time of the returned or simulated observation
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param liquidity The total pool liquidity at the time of the call
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return beforeOrAt The observation which occurred at, or before, the given timestamp
                              /// @return atOrAfter The observation which occurred at, or after, the given timestamp
                              function getSurroundingObservations(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32 target,
                                  int24 tick,
                                  uint16 index,
                                  uint128 liquidity,
                                  uint16 cardinality
                              ) private view returns (Observation memory beforeOrAt, Observation memory atOrAfter) {
                                  // optimistically set before to the newest observation
                                  beforeOrAt = self[index];
                                  // if the target is chronologically at or after the newest observation, we can early return
                                  if (lte(time, beforeOrAt.blockTimestamp, target)) {
                                      if (beforeOrAt.blockTimestamp == target) {
                                          // if newest observation equals target, we're in the same block, so we can ignore atOrAfter
                                          return (beforeOrAt, atOrAfter);
                                      } else {
                                          // otherwise, we need to transform
                                          return (beforeOrAt, transform(beforeOrAt, target, tick, liquidity));
                                      }
                                  }
                                  // now, set before to the oldest observation
                                  beforeOrAt = self[(index + 1) % cardinality];
                                  if (!beforeOrAt.initialized) beforeOrAt = self[0];
                                  // ensure that the target is chronologically at or after the oldest observation
                                  require(lte(time, beforeOrAt.blockTimestamp, target), 'OLD');
                                  // if we've reached this point, we have to binary search
                                  return binarySearch(self, time, target, index, cardinality);
                              }
                              /// @dev Reverts if an observation at or before the desired observation timestamp does not exist.
                              /// 0 may be passed as `secondsAgo' to return the current cumulative values.
                              /// If called with a timestamp falling between two observations, returns the counterfactual accumulator values
                              /// at exactly the timestamp between the two observations.
                              /// @param self The stored oracle array
                              /// @param time The current block timestamp
                              /// @param secondsAgo The amount of time to look back, in seconds, at which point to return an observation
                              /// @param tick The current tick
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param liquidity The current in-range pool liquidity
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return tickCumulative The tick * time elapsed since the pool was first initialized, as of `secondsAgo`
                              /// @return secondsPerLiquidityCumulativeX128 The time elapsed / max(1, liquidity) since the pool was first initialized, as of `secondsAgo`
                              function observeSingle(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32 secondsAgo,
                                  int24 tick,
                                  uint16 index,
                                  uint128 liquidity,
                                  uint16 cardinality
                              ) internal view returns (int56 tickCumulative, uint160 secondsPerLiquidityCumulativeX128) {
                                  if (secondsAgo == 0) {
                                      Observation memory last = self[index];
                                      if (last.blockTimestamp != time) last = transform(last, time, tick, liquidity);
                                      return (last.tickCumulative, last.secondsPerLiquidityCumulativeX128);
                                  }
                                  uint32 target = time - secondsAgo;
                                  (Observation memory beforeOrAt, Observation memory atOrAfter) =
                                      getSurroundingObservations(self, time, target, tick, index, liquidity, cardinality);
                                  if (target == beforeOrAt.blockTimestamp) {
                                      // we're at the left boundary
                                      return (beforeOrAt.tickCumulative, beforeOrAt.secondsPerLiquidityCumulativeX128);
                                  } else if (target == atOrAfter.blockTimestamp) {
                                      // we're at the right boundary
                                      return (atOrAfter.tickCumulative, atOrAfter.secondsPerLiquidityCumulativeX128);
                                  } else {
                                      // we're in the middle
                                      uint32 observationTimeDelta = atOrAfter.blockTimestamp - beforeOrAt.blockTimestamp;
                                      uint32 targetDelta = target - beforeOrAt.blockTimestamp;
                                      return (
                                          beforeOrAt.tickCumulative +
                                              ((atOrAfter.tickCumulative - beforeOrAt.tickCumulative) / observationTimeDelta) *
                                              targetDelta,
                                          beforeOrAt.secondsPerLiquidityCumulativeX128 +
                                              uint160(
                                                  (uint256(
                                                      atOrAfter.secondsPerLiquidityCumulativeX128 - beforeOrAt.secondsPerLiquidityCumulativeX128
                                                  ) * targetDelta) / observationTimeDelta
                                              )
                                      );
                                  }
                              }
                              /// @notice Returns the accumulator values as of each time seconds ago from the given time in the array of `secondsAgos`
                              /// @dev Reverts if `secondsAgos` > oldest observation
                              /// @param self The stored oracle array
                              /// @param time The current block.timestamp
                              /// @param secondsAgos Each amount of time to look back, in seconds, at which point to return an observation
                              /// @param tick The current tick
                              /// @param index The index of the observation that was most recently written to the observations array
                              /// @param liquidity The current in-range pool liquidity
                              /// @param cardinality The number of populated elements in the oracle array
                              /// @return tickCumulatives The tick * time elapsed since the pool was first initialized, as of each `secondsAgo`
                              /// @return secondsPerLiquidityCumulativeX128s The cumulative seconds / max(1, liquidity) since the pool was first initialized, as of each `secondsAgo`
                              function observe(
                                  Observation[65535] storage self,
                                  uint32 time,
                                  uint32[] memory secondsAgos,
                                  int24 tick,
                                  uint16 index,
                                  uint128 liquidity,
                                  uint16 cardinality
                              ) internal view returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s) {
                                  require(cardinality > 0, 'I');
                                  tickCumulatives = new int56[](secondsAgos.length);
                                  secondsPerLiquidityCumulativeX128s = new uint160[](secondsAgos.length);
                                  for (uint256 i = 0; i < secondsAgos.length; i++) {
                                      (tickCumulatives[i], secondsPerLiquidityCumulativeX128s[i]) = observeSingle(
                                          self,
                                          time,
                                          secondsAgos[i],
                                          tick,
                                          index,
                                          liquidity,
                                          cardinality
                                      );
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.4.0;
                          /// @title Contains 512-bit math functions
                          /// @notice Facilitates multiplication and division that can have overflow of an intermediate value without any loss of precision
                          /// @dev Handles "phantom overflow" i.e., allows multiplication and division where an intermediate value overflows 256 bits
                          library FullMath {
                              /// @notice Calculates floor(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
                              /// @param a The multiplicand
                              /// @param b The multiplier
                              /// @param denominator The divisor
                              /// @return result The 256-bit result
                              /// @dev Credit to Remco Bloemen under MIT license https://xn--2-umb.com/21/muldiv
                              function mulDiv(
                                  uint256 a,
                                  uint256 b,
                                  uint256 denominator
                              ) internal pure returns (uint256 result) {
                                  // 512-bit multiply [prod1 prod0] = a * b
                                  // Compute the product mod 2**256 and mod 2**256 - 1
                                  // then use the Chinese Remainder Theorem to reconstruct
                                  // the 512 bit result. The result is stored in two 256
                                  // variables such that product = prod1 * 2**256 + prod0
                                  uint256 prod0; // Least significant 256 bits of the product
                                  uint256 prod1; // Most significant 256 bits of the product
                                  assembly {
                                      let mm := mulmod(a, b, not(0))
                                      prod0 := mul(a, b)
                                      prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                                  }
                                  // Handle non-overflow cases, 256 by 256 division
                                  if (prod1 == 0) {
                                      require(denominator > 0);
                                      assembly {
                                          result := div(prod0, denominator)
                                      }
                                      return result;
                                  }
                                  // Make sure the result is less than 2**256.
                                  // Also prevents denominator == 0
                                  require(denominator > prod1);
                                  ///////////////////////////////////////////////
                                  // 512 by 256 division.
                                  ///////////////////////////////////////////////
                                  // Make division exact by subtracting the remainder from [prod1 prod0]
                                  // Compute remainder using mulmod
                                  uint256 remainder;
                                  assembly {
                                      remainder := mulmod(a, b, denominator)
                                  }
                                  // Subtract 256 bit number from 512 bit number
                                  assembly {
                                      prod1 := sub(prod1, gt(remainder, prod0))
                                      prod0 := sub(prod0, remainder)
                                  }
                                  // Factor powers of two out of denominator
                                  // Compute largest power of two divisor of denominator.
                                  // Always >= 1.
                                  uint256 twos = -denominator & denominator;
                                  // Divide denominator by power of two
                                  assembly {
                                      denominator := div(denominator, twos)
                                  }
                                  // Divide [prod1 prod0] by the factors of two
                                  assembly {
                                      prod0 := div(prod0, twos)
                                  }
                                  // Shift in bits from prod1 into prod0. For this we need
                                  // to flip `twos` such that it is 2**256 / twos.
                                  // If twos is zero, then it becomes one
                                  assembly {
                                      twos := add(div(sub(0, twos), twos), 1)
                                  }
                                  prod0 |= prod1 * twos;
                                  // Invert denominator mod 2**256
                                  // Now that denominator is an odd number, it has an inverse
                                  // modulo 2**256 such that denominator * inv = 1 mod 2**256.
                                  // Compute the inverse by starting with a seed that is correct
                                  // correct for four bits. That is, denominator * inv = 1 mod 2**4
                                  uint256 inv = (3 * denominator) ^ 2;
                                  // Now use Newton-Raphson iteration to improve the precision.
                                  // Thanks to Hensel's lifting lemma, this also works in modular
                                  // arithmetic, doubling the correct bits in each step.
                                  inv *= 2 - denominator * inv; // inverse mod 2**8
                                  inv *= 2 - denominator * inv; // inverse mod 2**16
                                  inv *= 2 - denominator * inv; // inverse mod 2**32
                                  inv *= 2 - denominator * inv; // inverse mod 2**64
                                  inv *= 2 - denominator * inv; // inverse mod 2**128
                                  inv *= 2 - denominator * inv; // inverse mod 2**256
                                  // Because the division is now exact we can divide by multiplying
                                  // with the modular inverse of denominator. This will give us the
                                  // correct result modulo 2**256. Since the precoditions guarantee
                                  // that the outcome is less than 2**256, this is the final result.
                                  // We don't need to compute the high bits of the result and prod1
                                  // is no longer required.
                                  result = prod0 * inv;
                                  return result;
                              }
                              /// @notice Calculates ceil(a×b÷denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
                              /// @param a The multiplicand
                              /// @param b The multiplier
                              /// @param denominator The divisor
                              /// @return result The 256-bit result
                              function mulDivRoundingUp(
                                  uint256 a,
                                  uint256 b,
                                  uint256 denominator
                              ) internal pure returns (uint256 result) {
                                  result = mulDiv(a, b, denominator);
                                  if (mulmod(a, b, denominator) > 0) {
                                      require(result < type(uint256).max);
                                      result++;
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.4.0;
                          /// @title FixedPoint128
                          /// @notice A library for handling binary fixed point numbers, see https://en.wikipedia.org/wiki/Q_(number_format)
                          library FixedPoint128 {
                              uint256 internal constant Q128 = 0x100000000000000000000000000000000;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.6.0;
                          import '../interfaces/IERC20Minimal.sol';
                          /// @title TransferHelper
                          /// @notice Contains helper methods for interacting with ERC20 tokens that do not consistently return true/false
                          library TransferHelper {
                              /// @notice Transfers tokens from msg.sender to a recipient
                              /// @dev Calls transfer on token contract, errors with TF if transfer fails
                              /// @param token The contract address of the token which will be transferred
                              /// @param to The recipient of the transfer
                              /// @param value The value of the transfer
                              function safeTransfer(
                                  address token,
                                  address to,
                                  uint256 value
                              ) internal {
                                  (bool success, bytes memory data) =
                                      token.call(abi.encodeWithSelector(IERC20Minimal.transfer.selector, to, value));
                                  require(success && (data.length == 0 || abi.decode(data, (bool))), 'TF');
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math library for computing sqrt prices from ticks and vice versa
                          /// @notice Computes sqrt price for ticks of size 1.0001, i.e. sqrt(1.0001^tick) as fixed point Q64.96 numbers. Supports
                          /// prices between 2**-128 and 2**128
                          library TickMath {
                              /// @dev The minimum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**-128
                              int24 internal constant MIN_TICK = -887272;
                              /// @dev The maximum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**128
                              int24 internal constant MAX_TICK = -MIN_TICK;
                              /// @dev The minimum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MIN_TICK)
                              uint160 internal constant MIN_SQRT_RATIO = 4295128739;
                              /// @dev The maximum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MAX_TICK)
                              uint160 internal constant MAX_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
                              /// @notice Calculates sqrt(1.0001^tick) * 2^96
                              /// @dev Throws if |tick| > max tick
                              /// @param tick The input tick for the above formula
                              /// @return sqrtPriceX96 A Fixed point Q64.96 number representing the sqrt of the ratio of the two assets (token1/token0)
                              /// at the given tick
                              function getSqrtRatioAtTick(int24 tick) internal pure returns (uint160 sqrtPriceX96) {
                                  uint256 absTick = tick < 0 ? uint256(-int256(tick)) : uint256(int256(tick));
                                  require(absTick <= uint256(MAX_TICK), 'T');
                                  uint256 ratio = absTick & 0x1 != 0 ? 0xfffcb933bd6fad37aa2d162d1a594001 : 0x100000000000000000000000000000000;
                                  if (absTick & 0x2 != 0) ratio = (ratio * 0xfff97272373d413259a46990580e213a) >> 128;
                                  if (absTick & 0x4 != 0) ratio = (ratio * 0xfff2e50f5f656932ef12357cf3c7fdcc) >> 128;
                                  if (absTick & 0x8 != 0) ratio = (ratio * 0xffe5caca7e10e4e61c3624eaa0941cd0) >> 128;
                                  if (absTick & 0x10 != 0) ratio = (ratio * 0xffcb9843d60f6159c9db58835c926644) >> 128;
                                  if (absTick & 0x20 != 0) ratio = (ratio * 0xff973b41fa98c081472e6896dfb254c0) >> 128;
                                  if (absTick & 0x40 != 0) ratio = (ratio * 0xff2ea16466c96a3843ec78b326b52861) >> 128;
                                  if (absTick & 0x80 != 0) ratio = (ratio * 0xfe5dee046a99a2a811c461f1969c3053) >> 128;
                                  if (absTick & 0x100 != 0) ratio = (ratio * 0xfcbe86c7900a88aedcffc83b479aa3a4) >> 128;
                                  if (absTick & 0x200 != 0) ratio = (ratio * 0xf987a7253ac413176f2b074cf7815e54) >> 128;
                                  if (absTick & 0x400 != 0) ratio = (ratio * 0xf3392b0822b70005940c7a398e4b70f3) >> 128;
                                  if (absTick & 0x800 != 0) ratio = (ratio * 0xe7159475a2c29b7443b29c7fa6e889d9) >> 128;
                                  if (absTick & 0x1000 != 0) ratio = (ratio * 0xd097f3bdfd2022b8845ad8f792aa5825) >> 128;
                                  if (absTick & 0x2000 != 0) ratio = (ratio * 0xa9f746462d870fdf8a65dc1f90e061e5) >> 128;
                                  if (absTick & 0x4000 != 0) ratio = (ratio * 0x70d869a156d2a1b890bb3df62baf32f7) >> 128;
                                  if (absTick & 0x8000 != 0) ratio = (ratio * 0x31be135f97d08fd981231505542fcfa6) >> 128;
                                  if (absTick & 0x10000 != 0) ratio = (ratio * 0x9aa508b5b7a84e1c677de54f3e99bc9) >> 128;
                                  if (absTick & 0x20000 != 0) ratio = (ratio * 0x5d6af8dedb81196699c329225ee604) >> 128;
                                  if (absTick & 0x40000 != 0) ratio = (ratio * 0x2216e584f5fa1ea926041bedfe98) >> 128;
                                  if (absTick & 0x80000 != 0) ratio = (ratio * 0x48a170391f7dc42444e8fa2) >> 128;
                                  if (tick > 0) ratio = type(uint256).max / ratio;
                                  // this divides by 1<<32 rounding up to go from a Q128.128 to a Q128.96.
                                  // we then downcast because we know the result always fits within 160 bits due to our tick input constraint
                                  // we round up in the division so getTickAtSqrtRatio of the output price is always consistent
                                  sqrtPriceX96 = uint160((ratio >> 32) + (ratio % (1 << 32) == 0 ? 0 : 1));
                              }
                              /// @notice Calculates the greatest tick value such that getRatioAtTick(tick) <= ratio
                              /// @dev Throws in case sqrtPriceX96 < MIN_SQRT_RATIO, as MIN_SQRT_RATIO is the lowest value getRatioAtTick may
                              /// ever return.
                              /// @param sqrtPriceX96 The sqrt ratio for which to compute the tick as a Q64.96
                              /// @return tick The greatest tick for which the ratio is less than or equal to the input ratio
                              function getTickAtSqrtRatio(uint160 sqrtPriceX96) internal pure returns (int24 tick) {
                                  // second inequality must be < because the price can never reach the price at the max tick
                                  require(sqrtPriceX96 >= MIN_SQRT_RATIO && sqrtPriceX96 < MAX_SQRT_RATIO, 'R');
                                  uint256 ratio = uint256(sqrtPriceX96) << 32;
                                  uint256 r = ratio;
                                  uint256 msb = 0;
                                  assembly {
                                      let f := shl(7, gt(r, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(6, gt(r, 0xFFFFFFFFFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(5, gt(r, 0xFFFFFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(4, gt(r, 0xFFFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(3, gt(r, 0xFF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(2, gt(r, 0xF))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := shl(1, gt(r, 0x3))
                                      msb := or(msb, f)
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      let f := gt(r, 0x1)
                                      msb := or(msb, f)
                                  }
                                  if (msb >= 128) r = ratio >> (msb - 127);
                                  else r = ratio << (127 - msb);
                                  int256 log_2 = (int256(msb) - 128) << 64;
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(63, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(62, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(61, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(60, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(59, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(58, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(57, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(56, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(55, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(54, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(53, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(52, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(51, f))
                                      r := shr(f, r)
                                  }
                                  assembly {
                                      r := shr(127, mul(r, r))
                                      let f := shr(128, r)
                                      log_2 := or(log_2, shl(50, f))
                                  }
                                  int256 log_sqrt10001 = log_2 * 255738958999603826347141; // 128.128 number
                                  int24 tickLow = int24((log_sqrt10001 - 3402992956809132418596140100660247210) >> 128);
                                  int24 tickHi = int24((log_sqrt10001 + 291339464771989622907027621153398088495) >> 128);
                                  tick = tickLow == tickHi ? tickLow : getSqrtRatioAtTick(tickHi) <= sqrtPriceX96 ? tickHi : tickLow;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math library for liquidity
                          library LiquidityMath {
                              /// @notice Add a signed liquidity delta to liquidity and revert if it overflows or underflows
                              /// @param x The liquidity before change
                              /// @param y The delta by which liquidity should be changed
                              /// @return z The liquidity delta
                              function addDelta(uint128 x, int128 y) internal pure returns (uint128 z) {
                                  if (y < 0) {
                                      require((z = x - uint128(-y)) < x, 'LS');
                                  } else {
                                      require((z = x + uint128(y)) >= x, 'LA');
                                  }
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './LowGasSafeMath.sol';
                          import './SafeCast.sol';
                          import './FullMath.sol';
                          import './UnsafeMath.sol';
                          import './FixedPoint96.sol';
                          /// @title Functions based on Q64.96 sqrt price and liquidity
                          /// @notice Contains the math that uses square root of price as a Q64.96 and liquidity to compute deltas
                          library SqrtPriceMath {
                              using LowGasSafeMath for uint256;
                              using SafeCast for uint256;
                              /// @notice Gets the next sqrt price given a delta of token0
                              /// @dev Always rounds up, because in the exact output case (increasing price) we need to move the price at least
                              /// far enough to get the desired output amount, and in the exact input case (decreasing price) we need to move the
                              /// price less in order to not send too much output.
                              /// The most precise formula for this is liquidity * sqrtPX96 / (liquidity +- amount * sqrtPX96),
                              /// if this is impossible because of overflow, we calculate liquidity / (liquidity / sqrtPX96 +- amount).
                              /// @param sqrtPX96 The starting price, i.e. before accounting for the token0 delta
                              /// @param liquidity The amount of usable liquidity
                              /// @param amount How much of token0 to add or remove from virtual reserves
                              /// @param add Whether to add or remove the amount of token0
                              /// @return The price after adding or removing amount, depending on add
                              function getNextSqrtPriceFromAmount0RoundingUp(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amount,
                                  bool add
                              ) internal pure returns (uint160) {
                                  // we short circuit amount == 0 because the result is otherwise not guaranteed to equal the input price
                                  if (amount == 0) return sqrtPX96;
                                  uint256 numerator1 = uint256(liquidity) << FixedPoint96.RESOLUTION;
                                  if (add) {
                                      uint256 product;
                                      if ((product = amount * sqrtPX96) / amount == sqrtPX96) {
                                          uint256 denominator = numerator1 + product;
                                          if (denominator >= numerator1)
                                              // always fits in 160 bits
                                              return uint160(FullMath.mulDivRoundingUp(numerator1, sqrtPX96, denominator));
                                      }
                                      return uint160(UnsafeMath.divRoundingUp(numerator1, (numerator1 / sqrtPX96).add(amount)));
                                  } else {
                                      uint256 product;
                                      // if the product overflows, we know the denominator underflows
                                      // in addition, we must check that the denominator does not underflow
                                      require((product = amount * sqrtPX96) / amount == sqrtPX96 && numerator1 > product);
                                      uint256 denominator = numerator1 - product;
                                      return FullMath.mulDivRoundingUp(numerator1, sqrtPX96, denominator).toUint160();
                                  }
                              }
                              /// @notice Gets the next sqrt price given a delta of token1
                              /// @dev Always rounds down, because in the exact output case (decreasing price) we need to move the price at least
                              /// far enough to get the desired output amount, and in the exact input case (increasing price) we need to move the
                              /// price less in order to not send too much output.
                              /// The formula we compute is within <1 wei of the lossless version: sqrtPX96 +- amount / liquidity
                              /// @param sqrtPX96 The starting price, i.e., before accounting for the token1 delta
                              /// @param liquidity The amount of usable liquidity
                              /// @param amount How much of token1 to add, or remove, from virtual reserves
                              /// @param add Whether to add, or remove, the amount of token1
                              /// @return The price after adding or removing `amount`
                              function getNextSqrtPriceFromAmount1RoundingDown(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amount,
                                  bool add
                              ) internal pure returns (uint160) {
                                  // if we're adding (subtracting), rounding down requires rounding the quotient down (up)
                                  // in both cases, avoid a mulDiv for most inputs
                                  if (add) {
                                      uint256 quotient =
                                          (
                                              amount <= type(uint160).max
                                                  ? (amount << FixedPoint96.RESOLUTION) / liquidity
                                                  : FullMath.mulDiv(amount, FixedPoint96.Q96, liquidity)
                                          );
                                      return uint256(sqrtPX96).add(quotient).toUint160();
                                  } else {
                                      uint256 quotient =
                                          (
                                              amount <= type(uint160).max
                                                  ? UnsafeMath.divRoundingUp(amount << FixedPoint96.RESOLUTION, liquidity)
                                                  : FullMath.mulDivRoundingUp(amount, FixedPoint96.Q96, liquidity)
                                          );
                                      require(sqrtPX96 > quotient);
                                      // always fits 160 bits
                                      return uint160(sqrtPX96 - quotient);
                                  }
                              }
                              /// @notice Gets the next sqrt price given an input amount of token0 or token1
                              /// @dev Throws if price or liquidity are 0, or if the next price is out of bounds
                              /// @param sqrtPX96 The starting price, i.e., before accounting for the input amount
                              /// @param liquidity The amount of usable liquidity
                              /// @param amountIn How much of token0, or token1, is being swapped in
                              /// @param zeroForOne Whether the amount in is token0 or token1
                              /// @return sqrtQX96 The price after adding the input amount to token0 or token1
                              function getNextSqrtPriceFromInput(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amountIn,
                                  bool zeroForOne
                              ) internal pure returns (uint160 sqrtQX96) {
                                  require(sqrtPX96 > 0);
                                  require(liquidity > 0);
                                  // round to make sure that we don't pass the target price
                                  return
                                      zeroForOne
                                          ? getNextSqrtPriceFromAmount0RoundingUp(sqrtPX96, liquidity, amountIn, true)
                                          : getNextSqrtPriceFromAmount1RoundingDown(sqrtPX96, liquidity, amountIn, true);
                              }
                              /// @notice Gets the next sqrt price given an output amount of token0 or token1
                              /// @dev Throws if price or liquidity are 0 or the next price is out of bounds
                              /// @param sqrtPX96 The starting price before accounting for the output amount
                              /// @param liquidity The amount of usable liquidity
                              /// @param amountOut How much of token0, or token1, is being swapped out
                              /// @param zeroForOne Whether the amount out is token0 or token1
                              /// @return sqrtQX96 The price after removing the output amount of token0 or token1
                              function getNextSqrtPriceFromOutput(
                                  uint160 sqrtPX96,
                                  uint128 liquidity,
                                  uint256 amountOut,
                                  bool zeroForOne
                              ) internal pure returns (uint160 sqrtQX96) {
                                  require(sqrtPX96 > 0);
                                  require(liquidity > 0);
                                  // round to make sure that we pass the target price
                                  return
                                      zeroForOne
                                          ? getNextSqrtPriceFromAmount1RoundingDown(sqrtPX96, liquidity, amountOut, false)
                                          : getNextSqrtPriceFromAmount0RoundingUp(sqrtPX96, liquidity, amountOut, false);
                              }
                              /// @notice Gets the amount0 delta between two prices
                              /// @dev Calculates liquidity / sqrt(lower) - liquidity / sqrt(upper),
                              /// i.e. liquidity * (sqrt(upper) - sqrt(lower)) / (sqrt(upper) * sqrt(lower))
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The amount of usable liquidity
                              /// @param roundUp Whether to round the amount up or down
                              /// @return amount0 Amount of token0 required to cover a position of size liquidity between the two passed prices
                              function getAmount0Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  uint128 liquidity,
                                  bool roundUp
                              ) internal pure returns (uint256 amount0) {
                                  if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
                                  uint256 numerator1 = uint256(liquidity) << FixedPoint96.RESOLUTION;
                                  uint256 numerator2 = sqrtRatioBX96 - sqrtRatioAX96;
                                  require(sqrtRatioAX96 > 0);
                                  return
                                      roundUp
                                          ? UnsafeMath.divRoundingUp(
                                              FullMath.mulDivRoundingUp(numerator1, numerator2, sqrtRatioBX96),
                                              sqrtRatioAX96
                                          )
                                          : FullMath.mulDiv(numerator1, numerator2, sqrtRatioBX96) / sqrtRatioAX96;
                              }
                              /// @notice Gets the amount1 delta between two prices
                              /// @dev Calculates liquidity * (sqrt(upper) - sqrt(lower))
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The amount of usable liquidity
                              /// @param roundUp Whether to round the amount up, or down
                              /// @return amount1 Amount of token1 required to cover a position of size liquidity between the two passed prices
                              function getAmount1Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  uint128 liquidity,
                                  bool roundUp
                              ) internal pure returns (uint256 amount1) {
                                  if (sqrtRatioAX96 > sqrtRatioBX96) (sqrtRatioAX96, sqrtRatioBX96) = (sqrtRatioBX96, sqrtRatioAX96);
                                  return
                                      roundUp
                                          ? FullMath.mulDivRoundingUp(liquidity, sqrtRatioBX96 - sqrtRatioAX96, FixedPoint96.Q96)
                                          : FullMath.mulDiv(liquidity, sqrtRatioBX96 - sqrtRatioAX96, FixedPoint96.Q96);
                              }
                              /// @notice Helper that gets signed token0 delta
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The change in liquidity for which to compute the amount0 delta
                              /// @return amount0 Amount of token0 corresponding to the passed liquidityDelta between the two prices
                              function getAmount0Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  int128 liquidity
                              ) internal pure returns (int256 amount0) {
                                  return
                                      liquidity < 0
                                          ? -getAmount0Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(-liquidity), false).toInt256()
                                          : getAmount0Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(liquidity), true).toInt256();
                              }
                              /// @notice Helper that gets signed token1 delta
                              /// @param sqrtRatioAX96 A sqrt price
                              /// @param sqrtRatioBX96 Another sqrt price
                              /// @param liquidity The change in liquidity for which to compute the amount1 delta
                              /// @return amount1 Amount of token1 corresponding to the passed liquidityDelta between the two prices
                              function getAmount1Delta(
                                  uint160 sqrtRatioAX96,
                                  uint160 sqrtRatioBX96,
                                  int128 liquidity
                              ) internal pure returns (int256 amount1) {
                                  return
                                      liquidity < 0
                                          ? -getAmount1Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(-liquidity), false).toInt256()
                                          : getAmount1Delta(sqrtRatioAX96, sqrtRatioBX96, uint128(liquidity), true).toInt256();
                              }
                          }
                          // SPDX-License-Identifier: BUSL-1.1
                          pragma solidity >=0.5.0;
                          import './FullMath.sol';
                          import './SqrtPriceMath.sol';
                          /// @title Computes the result of a swap within ticks
                          /// @notice Contains methods for computing the result of a swap within a single tick price range, i.e., a single tick.
                          library SwapMath {
                              /// @notice Computes the result of swapping some amount in, or amount out, given the parameters of the swap
                              /// @dev The fee, plus the amount in, will never exceed the amount remaining if the swap's `amountSpecified` is positive
                              /// @param sqrtRatioCurrentX96 The current sqrt price of the pool
                              /// @param sqrtRatioTargetX96 The price that cannot be exceeded, from which the direction of the swap is inferred
                              /// @param liquidity The usable liquidity
                              /// @param amountRemaining How much input or output amount is remaining to be swapped in/out
                              /// @param feePips The fee taken from the input amount, expressed in hundredths of a bip
                              /// @return sqrtRatioNextX96 The price after swapping the amount in/out, not to exceed the price target
                              /// @return amountIn The amount to be swapped in, of either token0 or token1, based on the direction of the swap
                              /// @return amountOut The amount to be received, of either token0 or token1, based on the direction of the swap
                              /// @return feeAmount The amount of input that will be taken as a fee
                              function computeSwapStep(
                                  uint160 sqrtRatioCurrentX96,
                                  uint160 sqrtRatioTargetX96,
                                  uint128 liquidity,
                                  int256 amountRemaining,
                                  uint24 feePips
                              )
                                  internal
                                  pure
                                  returns (
                                      uint160 sqrtRatioNextX96,
                                      uint256 amountIn,
                                      uint256 amountOut,
                                      uint256 feeAmount
                                  )
                              {
                                  bool zeroForOne = sqrtRatioCurrentX96 >= sqrtRatioTargetX96;
                                  bool exactIn = amountRemaining >= 0;
                                  if (exactIn) {
                                      uint256 amountRemainingLessFee = FullMath.mulDiv(uint256(amountRemaining), 1e6 - feePips, 1e6);
                                      amountIn = zeroForOne
                                          ? SqrtPriceMath.getAmount0Delta(sqrtRatioTargetX96, sqrtRatioCurrentX96, liquidity, true)
                                          : SqrtPriceMath.getAmount1Delta(sqrtRatioCurrentX96, sqrtRatioTargetX96, liquidity, true);
                                      if (amountRemainingLessFee >= amountIn) sqrtRatioNextX96 = sqrtRatioTargetX96;
                                      else
                                          sqrtRatioNextX96 = SqrtPriceMath.getNextSqrtPriceFromInput(
                                              sqrtRatioCurrentX96,
                                              liquidity,
                                              amountRemainingLessFee,
                                              zeroForOne
                                          );
                                  } else {
                                      amountOut = zeroForOne
                                          ? SqrtPriceMath.getAmount1Delta(sqrtRatioTargetX96, sqrtRatioCurrentX96, liquidity, false)
                                          : SqrtPriceMath.getAmount0Delta(sqrtRatioCurrentX96, sqrtRatioTargetX96, liquidity, false);
                                      if (uint256(-amountRemaining) >= amountOut) sqrtRatioNextX96 = sqrtRatioTargetX96;
                                      else
                                          sqrtRatioNextX96 = SqrtPriceMath.getNextSqrtPriceFromOutput(
                                              sqrtRatioCurrentX96,
                                              liquidity,
                                              uint256(-amountRemaining),
                                              zeroForOne
                                          );
                                  }
                                  bool max = sqrtRatioTargetX96 == sqrtRatioNextX96;
                                  // get the input/output amounts
                                  if (zeroForOne) {
                                      amountIn = max && exactIn
                                          ? amountIn
                                          : SqrtPriceMath.getAmount0Delta(sqrtRatioNextX96, sqrtRatioCurrentX96, liquidity, true);
                                      amountOut = max && !exactIn
                                          ? amountOut
                                          : SqrtPriceMath.getAmount1Delta(sqrtRatioNextX96, sqrtRatioCurrentX96, liquidity, false);
                                  } else {
                                      amountIn = max && exactIn
                                          ? amountIn
                                          : SqrtPriceMath.getAmount1Delta(sqrtRatioCurrentX96, sqrtRatioNextX96, liquidity, true);
                                      amountOut = max && !exactIn
                                          ? amountOut
                                          : SqrtPriceMath.getAmount0Delta(sqrtRatioCurrentX96, sqrtRatioNextX96, liquidity, false);
                                  }
                                  // cap the output amount to not exceed the remaining output amount
                                  if (!exactIn && amountOut > uint256(-amountRemaining)) {
                                      amountOut = uint256(-amountRemaining);
                                  }
                                  if (exactIn && sqrtRatioNextX96 != sqrtRatioTargetX96) {
                                      // we didn't reach the target, so take the remainder of the maximum input as fee
                                      feeAmount = uint256(amountRemaining) - amountIn;
                                  } else {
                                      feeAmount = FullMath.mulDivRoundingUp(amountIn, feePips, 1e6 - feePips);
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title An interface for a contract that is capable of deploying Uniswap V3 Pools
                          /// @notice A contract that constructs a pool must implement this to pass arguments to the pool
                          /// @dev This is used to avoid having constructor arguments in the pool contract, which results in the init code hash
                          /// of the pool being constant allowing the CREATE2 address of the pool to be cheaply computed on-chain
                          interface IUniswapV3PoolDeployer {
                              /// @notice Get the parameters to be used in constructing the pool, set transiently during pool creation.
                              /// @dev Called by the pool constructor to fetch the parameters of the pool
                              /// Returns factory The factory address
                              /// Returns token0 The first token of the pool by address sort order
                              /// Returns token1 The second token of the pool by address sort order
                              /// Returns fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// Returns tickSpacing The minimum number of ticks between initialized ticks
                              function parameters()
                                  external
                                  view
                                  returns (
                                      address factory,
                                      address token0,
                                      address token1,
                                      uint24 fee,
                                      int24 tickSpacing
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title The interface for the Uniswap V3 Factory
                          /// @notice The Uniswap V3 Factory facilitates creation of Uniswap V3 pools and control over the protocol fees
                          interface IUniswapV3Factory {
                              /// @notice Emitted when the owner of the factory is changed
                              /// @param oldOwner The owner before the owner was changed
                              /// @param newOwner The owner after the owner was changed
                              event OwnerChanged(address indexed oldOwner, address indexed newOwner);
                              /// @notice Emitted when a pool is created
                              /// @param token0 The first token of the pool by address sort order
                              /// @param token1 The second token of the pool by address sort order
                              /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// @param tickSpacing The minimum number of ticks between initialized ticks
                              /// @param pool The address of the created pool
                              event PoolCreated(
                                  address indexed token0,
                                  address indexed token1,
                                  uint24 indexed fee,
                                  int24 tickSpacing,
                                  address pool
                              );
                              /// @notice Emitted when a new fee amount is enabled for pool creation via the factory
                              /// @param fee The enabled fee, denominated in hundredths of a bip
                              /// @param tickSpacing The minimum number of ticks between initialized ticks for pools created with the given fee
                              event FeeAmountEnabled(uint24 indexed fee, int24 indexed tickSpacing);
                              /// @notice Returns the current owner of the factory
                              /// @dev Can be changed by the current owner via setOwner
                              /// @return The address of the factory owner
                              function owner() external view returns (address);
                              /// @notice Returns the tick spacing for a given fee amount, if enabled, or 0 if not enabled
                              /// @dev A fee amount can never be removed, so this value should be hard coded or cached in the calling context
                              /// @param fee The enabled fee, denominated in hundredths of a bip. Returns 0 in case of unenabled fee
                              /// @return The tick spacing
                              function feeAmountTickSpacing(uint24 fee) external view returns (int24);
                              /// @notice Returns the pool address for a given pair of tokens and a fee, or address 0 if it does not exist
                              /// @dev tokenA and tokenB may be passed in either token0/token1 or token1/token0 order
                              /// @param tokenA The contract address of either token0 or token1
                              /// @param tokenB The contract address of the other token
                              /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                              /// @return pool The pool address
                              function getPool(
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) external view returns (address pool);
                              /// @notice Creates a pool for the given two tokens and fee
                              /// @param tokenA One of the two tokens in the desired pool
                              /// @param tokenB The other of the two tokens in the desired pool
                              /// @param fee The desired fee for the pool
                              /// @dev tokenA and tokenB may be passed in either order: token0/token1 or token1/token0. tickSpacing is retrieved
                              /// from the fee. The call will revert if the pool already exists, the fee is invalid, or the token arguments
                              /// are invalid.
                              /// @return pool The address of the newly created pool
                              function createPool(
                                  address tokenA,
                                  address tokenB,
                                  uint24 fee
                              ) external returns (address pool);
                              /// @notice Updates the owner of the factory
                              /// @dev Must be called by the current owner
                              /// @param _owner The new owner of the factory
                              function setOwner(address _owner) external;
                              /// @notice Enables a fee amount with the given tickSpacing
                              /// @dev Fee amounts may never be removed once enabled
                              /// @param fee The fee amount to enable, denominated in hundredths of a bip (i.e. 1e-6)
                              /// @param tickSpacing The spacing between ticks to be enforced for all pools created with the given fee amount
                              function enableFeeAmount(uint24 fee, int24 tickSpacing) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Minimal ERC20 interface for Uniswap
                          /// @notice Contains a subset of the full ERC20 interface that is used in Uniswap V3
                          interface IERC20Minimal {
                              /// @notice Returns the balance of a token
                              /// @param account The account for which to look up the number of tokens it has, i.e. its balance
                              /// @return The number of tokens held by the account
                              function balanceOf(address account) external view returns (uint256);
                              /// @notice Transfers the amount of token from the `msg.sender` to the recipient
                              /// @param recipient The account that will receive the amount transferred
                              /// @param amount The number of tokens to send from the sender to the recipient
                              /// @return Returns true for a successful transfer, false for an unsuccessful transfer
                              function transfer(address recipient, uint256 amount) external returns (bool);
                              /// @notice Returns the current allowance given to a spender by an owner
                              /// @param owner The account of the token owner
                              /// @param spender The account of the token spender
                              /// @return The current allowance granted by `owner` to `spender`
                              function allowance(address owner, address spender) external view returns (uint256);
                              /// @notice Sets the allowance of a spender from the `msg.sender` to the value `amount`
                              /// @param spender The account which will be allowed to spend a given amount of the owners tokens
                              /// @param amount The amount of tokens allowed to be used by `spender`
                              /// @return Returns true for a successful approval, false for unsuccessful
                              function approve(address spender, uint256 amount) external returns (bool);
                              /// @notice Transfers `amount` tokens from `sender` to `recipient` up to the allowance given to the `msg.sender`
                              /// @param sender The account from which the transfer will be initiated
                              /// @param recipient The recipient of the transfer
                              /// @param amount The amount of the transfer
                              /// @return Returns true for a successful transfer, false for unsuccessful
                              function transferFrom(
                                  address sender,
                                  address recipient,
                                  uint256 amount
                              ) external returns (bool);
                              /// @notice Event emitted when tokens are transferred from one address to another, either via `#transfer` or `#transferFrom`.
                              /// @param from The account from which the tokens were sent, i.e. the balance decreased
                              /// @param to The account to which the tokens were sent, i.e. the balance increased
                              /// @param value The amount of tokens that were transferred
                              event Transfer(address indexed from, address indexed to, uint256 value);
                              /// @notice Event emitted when the approval amount for the spender of a given owner's tokens changes.
                              /// @param owner The account that approved spending of its tokens
                              /// @param spender The account for which the spending allowance was modified
                              /// @param value The new allowance from the owner to the spender
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#mint
                          /// @notice Any contract that calls IUniswapV3PoolActions#mint must implement this interface
                          interface IUniswapV3MintCallback {
                              /// @notice Called to `msg.sender` after minting liquidity to a position from IUniswapV3Pool#mint.
                              /// @dev In the implementation you must pay the pool tokens owed for the minted liquidity.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// @param amount0Owed The amount of token0 due to the pool for the minted liquidity
                              /// @param amount1Owed The amount of token1 due to the pool for the minted liquidity
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#mint call
                              function uniswapV3MintCallback(
                                  uint256 amount0Owed,
                                  uint256 amount1Owed,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#swap
                          /// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
                          interface IUniswapV3SwapCallback {
                              /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
                              /// @dev In the implementation you must pay the pool tokens owed for the swap.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
                              /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
                              /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
                              /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
                              function uniswapV3SwapCallback(
                                  int256 amount0Delta,
                                  int256 amount1Delta,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Callback for IUniswapV3PoolActions#flash
                          /// @notice Any contract that calls IUniswapV3PoolActions#flash must implement this interface
                          interface IUniswapV3FlashCallback {
                              /// @notice Called to `msg.sender` after transferring to the recipient from IUniswapV3Pool#flash.
                              /// @dev In the implementation you must repay the pool the tokens sent by flash plus the computed fee amounts.
                              /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                              /// @param fee0 The fee amount in token0 due to the pool by the end of the flash
                              /// @param fee1 The fee amount in token1 due to the pool by the end of the flash
                              /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#flash call
                              function uniswapV3FlashCallback(
                                  uint256 fee0,
                                  uint256 fee1,
                                  bytes calldata data
                              ) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that never changes
                          /// @notice These parameters are fixed for a pool forever, i.e., the methods will always return the same values
                          interface IUniswapV3PoolImmutables {
                              /// @notice The contract that deployed the pool, which must adhere to the IUniswapV3Factory interface
                              /// @return The contract address
                              function factory() external view returns (address);
                              /// @notice The first of the two tokens of the pool, sorted by address
                              /// @return The token contract address
                              function token0() external view returns (address);
                              /// @notice The second of the two tokens of the pool, sorted by address
                              /// @return The token contract address
                              function token1() external view returns (address);
                              /// @notice The pool's fee in hundredths of a bip, i.e. 1e-6
                              /// @return The fee
                              function fee() external view returns (uint24);
                              /// @notice The pool tick spacing
                              /// @dev Ticks can only be used at multiples of this value, minimum of 1 and always positive
                              /// e.g.: a tickSpacing of 3 means ticks can be initialized every 3rd tick, i.e., ..., -6, -3, 0, 3, 6, ...
                              /// This value is an int24 to avoid casting even though it is always positive.
                              /// @return The tick spacing
                              function tickSpacing() external view returns (int24);
                              /// @notice The maximum amount of position liquidity that can use any tick in the range
                              /// @dev This parameter is enforced per tick to prevent liquidity from overflowing a uint128 at any point, and
                              /// also prevents out-of-range liquidity from being used to prevent adding in-range liquidity to a pool
                              /// @return The max amount of liquidity per tick
                              function maxLiquidityPerTick() external view returns (uint128);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that can change
                          /// @notice These methods compose the pool's state, and can change with any frequency including multiple times
                          /// per transaction
                          interface IUniswapV3PoolState {
                              /// @notice The 0th storage slot in the pool stores many values, and is exposed as a single method to save gas
                              /// when accessed externally.
                              /// @return sqrtPriceX96 The current price of the pool as a sqrt(token1/token0) Q64.96 value
                              /// tick The current tick of the pool, i.e. according to the last tick transition that was run.
                              /// This value may not always be equal to SqrtTickMath.getTickAtSqrtRatio(sqrtPriceX96) if the price is on a tick
                              /// boundary.
                              /// observationIndex The index of the last oracle observation that was written,
                              /// observationCardinality The current maximum number of observations stored in the pool,
                              /// observationCardinalityNext The next maximum number of observations, to be updated when the observation.
                              /// feeProtocol The protocol fee for both tokens of the pool.
                              /// Encoded as two 4 bit values, where the protocol fee of token1 is shifted 4 bits and the protocol fee of token0
                              /// is the lower 4 bits. Used as the denominator of a fraction of the swap fee, e.g. 4 means 1/4th of the swap fee.
                              /// unlocked Whether the pool is currently locked to reentrancy
                              function slot0()
                                  external
                                  view
                                  returns (
                                      uint160 sqrtPriceX96,
                                      int24 tick,
                                      uint16 observationIndex,
                                      uint16 observationCardinality,
                                      uint16 observationCardinalityNext,
                                      uint8 feeProtocol,
                                      bool unlocked
                                  );
                              /// @notice The fee growth as a Q128.128 fees of token0 collected per unit of liquidity for the entire life of the pool
                              /// @dev This value can overflow the uint256
                              function feeGrowthGlobal0X128() external view returns (uint256);
                              /// @notice The fee growth as a Q128.128 fees of token1 collected per unit of liquidity for the entire life of the pool
                              /// @dev This value can overflow the uint256
                              function feeGrowthGlobal1X128() external view returns (uint256);
                              /// @notice The amounts of token0 and token1 that are owed to the protocol
                              /// @dev Protocol fees will never exceed uint128 max in either token
                              function protocolFees() external view returns (uint128 token0, uint128 token1);
                              /// @notice The currently in range liquidity available to the pool
                              /// @dev This value has no relationship to the total liquidity across all ticks
                              function liquidity() external view returns (uint128);
                              /// @notice Look up information about a specific tick in the pool
                              /// @param tick The tick to look up
                              /// @return liquidityGross the total amount of position liquidity that uses the pool either as tick lower or
                              /// tick upper,
                              /// liquidityNet how much liquidity changes when the pool price crosses the tick,
                              /// feeGrowthOutside0X128 the fee growth on the other side of the tick from the current tick in token0,
                              /// feeGrowthOutside1X128 the fee growth on the other side of the tick from the current tick in token1,
                              /// tickCumulativeOutside the cumulative tick value on the other side of the tick from the current tick
                              /// secondsPerLiquidityOutsideX128 the seconds spent per liquidity on the other side of the tick from the current tick,
                              /// secondsOutside the seconds spent on the other side of the tick from the current tick,
                              /// initialized Set to true if the tick is initialized, i.e. liquidityGross is greater than 0, otherwise equal to false.
                              /// Outside values can only be used if the tick is initialized, i.e. if liquidityGross is greater than 0.
                              /// In addition, these values are only relative and must be used only in comparison to previous snapshots for
                              /// a specific position.
                              function ticks(int24 tick)
                                  external
                                  view
                                  returns (
                                      uint128 liquidityGross,
                                      int128 liquidityNet,
                                      uint256 feeGrowthOutside0X128,
                                      uint256 feeGrowthOutside1X128,
                                      int56 tickCumulativeOutside,
                                      uint160 secondsPerLiquidityOutsideX128,
                                      uint32 secondsOutside,
                                      bool initialized
                                  );
                              /// @notice Returns 256 packed tick initialized boolean values. See TickBitmap for more information
                              function tickBitmap(int16 wordPosition) external view returns (uint256);
                              /// @notice Returns the information about a position by the position's key
                              /// @param key The position's key is a hash of a preimage composed by the owner, tickLower and tickUpper
                              /// @return _liquidity The amount of liquidity in the position,
                              /// Returns feeGrowthInside0LastX128 fee growth of token0 inside the tick range as of the last mint/burn/poke,
                              /// Returns feeGrowthInside1LastX128 fee growth of token1 inside the tick range as of the last mint/burn/poke,
                              /// Returns tokensOwed0 the computed amount of token0 owed to the position as of the last mint/burn/poke,
                              /// Returns tokensOwed1 the computed amount of token1 owed to the position as of the last mint/burn/poke
                              function positions(bytes32 key)
                                  external
                                  view
                                  returns (
                                      uint128 _liquidity,
                                      uint256 feeGrowthInside0LastX128,
                                      uint256 feeGrowthInside1LastX128,
                                      uint128 tokensOwed0,
                                      uint128 tokensOwed1
                                  );
                              /// @notice Returns data about a specific observation index
                              /// @param index The element of the observations array to fetch
                              /// @dev You most likely want to use #observe() instead of this method to get an observation as of some amount of time
                              /// ago, rather than at a specific index in the array.
                              /// @return blockTimestamp The timestamp of the observation,
                              /// Returns tickCumulative the tick multiplied by seconds elapsed for the life of the pool as of the observation timestamp,
                              /// Returns secondsPerLiquidityCumulativeX128 the seconds per in range liquidity for the life of the pool as of the observation timestamp,
                              /// Returns initialized whether the observation has been initialized and the values are safe to use
                              function observations(uint256 index)
                                  external
                                  view
                                  returns (
                                      uint32 blockTimestamp,
                                      int56 tickCumulative,
                                      uint160 secondsPerLiquidityCumulativeX128,
                                      bool initialized
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Pool state that is not stored
                          /// @notice Contains view functions to provide information about the pool that is computed rather than stored on the
                          /// blockchain. The functions here may have variable gas costs.
                          interface IUniswapV3PoolDerivedState {
                              /// @notice Returns the cumulative tick and liquidity as of each timestamp `secondsAgo` from the current block timestamp
                              /// @dev To get a time weighted average tick or liquidity-in-range, you must call this with two values, one representing
                              /// the beginning of the period and another for the end of the period. E.g., to get the last hour time-weighted average tick,
                              /// you must call it with secondsAgos = [3600, 0].
                              /// @dev The time weighted average tick represents the geometric time weighted average price of the pool, in
                              /// log base sqrt(1.0001) of token1 / token0. The TickMath library can be used to go from a tick value to a ratio.
                              /// @param secondsAgos From how long ago each cumulative tick and liquidity value should be returned
                              /// @return tickCumulatives Cumulative tick values as of each `secondsAgos` from the current block timestamp
                              /// @return secondsPerLiquidityCumulativeX128s Cumulative seconds per liquidity-in-range value as of each `secondsAgos` from the current block
                              /// timestamp
                              function observe(uint32[] calldata secondsAgos)
                                  external
                                  view
                                  returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s);
                              /// @notice Returns a snapshot of the tick cumulative, seconds per liquidity and seconds inside a tick range
                              /// @dev Snapshots must only be compared to other snapshots, taken over a period for which a position existed.
                              /// I.e., snapshots cannot be compared if a position is not held for the entire period between when the first
                              /// snapshot is taken and the second snapshot is taken.
                              /// @param tickLower The lower tick of the range
                              /// @param tickUpper The upper tick of the range
                              /// @return tickCumulativeInside The snapshot of the tick accumulator for the range
                              /// @return secondsPerLiquidityInsideX128 The snapshot of seconds per liquidity for the range
                              /// @return secondsInside The snapshot of seconds per liquidity for the range
                              function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
                                  external
                                  view
                                  returns (
                                      int56 tickCumulativeInside,
                                      uint160 secondsPerLiquidityInsideX128,
                                      uint32 secondsInside
                                  );
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Permissionless pool actions
                          /// @notice Contains pool methods that can be called by anyone
                          interface IUniswapV3PoolActions {
                              /// @notice Sets the initial price for the pool
                              /// @dev Price is represented as a sqrt(amountToken1/amountToken0) Q64.96 value
                              /// @param sqrtPriceX96 the initial sqrt price of the pool as a Q64.96
                              function initialize(uint160 sqrtPriceX96) external;
                              /// @notice Adds liquidity for the given recipient/tickLower/tickUpper position
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3MintCallback#uniswapV3MintCallback
                              /// in which they must pay any token0 or token1 owed for the liquidity. The amount of token0/token1 due depends
                              /// on tickLower, tickUpper, the amount of liquidity, and the current price.
                              /// @param recipient The address for which the liquidity will be created
                              /// @param tickLower The lower tick of the position in which to add liquidity
                              /// @param tickUpper The upper tick of the position in which to add liquidity
                              /// @param amount The amount of liquidity to mint
                              /// @param data Any data that should be passed through to the callback
                              /// @return amount0 The amount of token0 that was paid to mint the given amount of liquidity. Matches the value in the callback
                              /// @return amount1 The amount of token1 that was paid to mint the given amount of liquidity. Matches the value in the callback
                              function mint(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount,
                                  bytes calldata data
                              ) external returns (uint256 amount0, uint256 amount1);
                              /// @notice Collects tokens owed to a position
                              /// @dev Does not recompute fees earned, which must be done either via mint or burn of any amount of liquidity.
                              /// Collect must be called by the position owner. To withdraw only token0 or only token1, amount0Requested or
                              /// amount1Requested may be set to zero. To withdraw all tokens owed, caller may pass any value greater than the
                              /// actual tokens owed, e.g. type(uint128).max. Tokens owed may be from accumulated swap fees or burned liquidity.
                              /// @param recipient The address which should receive the fees collected
                              /// @param tickLower The lower tick of the position for which to collect fees
                              /// @param tickUpper The upper tick of the position for which to collect fees
                              /// @param amount0Requested How much token0 should be withdrawn from the fees owed
                              /// @param amount1Requested How much token1 should be withdrawn from the fees owed
                              /// @return amount0 The amount of fees collected in token0
                              /// @return amount1 The amount of fees collected in token1
                              function collect(
                                  address recipient,
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external returns (uint128 amount0, uint128 amount1);
                              /// @notice Burn liquidity from the sender and account tokens owed for the liquidity to the position
                              /// @dev Can be used to trigger a recalculation of fees owed to a position by calling with an amount of 0
                              /// @dev Fees must be collected separately via a call to #collect
                              /// @param tickLower The lower tick of the position for which to burn liquidity
                              /// @param tickUpper The upper tick of the position for which to burn liquidity
                              /// @param amount How much liquidity to burn
                              /// @return amount0 The amount of token0 sent to the recipient
                              /// @return amount1 The amount of token1 sent to the recipient
                              function burn(
                                  int24 tickLower,
                                  int24 tickUpper,
                                  uint128 amount
                              ) external returns (uint256 amount0, uint256 amount1);
                              /// @notice Swap token0 for token1, or token1 for token0
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
                              /// @param recipient The address to receive the output of the swap
                              /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
                              /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
                              /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
                              /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
                              /// @param data Any data to be passed through to the callback
                              /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
                              /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
                              function swap(
                                  address recipient,
                                  bool zeroForOne,
                                  int256 amountSpecified,
                                  uint160 sqrtPriceLimitX96,
                                  bytes calldata data
                              ) external returns (int256 amount0, int256 amount1);
                              /// @notice Receive token0 and/or token1 and pay it back, plus a fee, in the callback
                              /// @dev The caller of this method receives a callback in the form of IUniswapV3FlashCallback#uniswapV3FlashCallback
                              /// @dev Can be used to donate underlying tokens pro-rata to currently in-range liquidity providers by calling
                              /// with 0 amount{0,1} and sending the donation amount(s) from the callback
                              /// @param recipient The address which will receive the token0 and token1 amounts
                              /// @param amount0 The amount of token0 to send
                              /// @param amount1 The amount of token1 to send
                              /// @param data Any data to be passed through to the callback
                              function flash(
                                  address recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  bytes calldata data
                              ) external;
                              /// @notice Increase the maximum number of price and liquidity observations that this pool will store
                              /// @dev This method is no-op if the pool already has an observationCardinalityNext greater than or equal to
                              /// the input observationCardinalityNext.
                              /// @param observationCardinalityNext The desired minimum number of observations for the pool to store
                              function increaseObservationCardinalityNext(uint16 observationCardinalityNext) external;
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Permissioned pool actions
                          /// @notice Contains pool methods that may only be called by the factory owner
                          interface IUniswapV3PoolOwnerActions {
                              /// @notice Set the denominator of the protocol's % share of the fees
                              /// @param feeProtocol0 new protocol fee for token0 of the pool
                              /// @param feeProtocol1 new protocol fee for token1 of the pool
                              function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external;
                              /// @notice Collect the protocol fee accrued to the pool
                              /// @param recipient The address to which collected protocol fees should be sent
                              /// @param amount0Requested The maximum amount of token0 to send, can be 0 to collect fees in only token1
                              /// @param amount1Requested The maximum amount of token1 to send, can be 0 to collect fees in only token0
                              /// @return amount0 The protocol fee collected in token0
                              /// @return amount1 The protocol fee collected in token1
                              function collectProtocol(
                                  address recipient,
                                  uint128 amount0Requested,
                                  uint128 amount1Requested
                              ) external returns (uint128 amount0, uint128 amount1);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Events emitted by a pool
                          /// @notice Contains all events emitted by the pool
                          interface IUniswapV3PoolEvents {
                              /// @notice Emitted exactly once by a pool when #initialize is first called on the pool
                              /// @dev Mint/Burn/Swap cannot be emitted by the pool before Initialize
                              /// @param sqrtPriceX96 The initial sqrt price of the pool, as a Q64.96
                              /// @param tick The initial tick of the pool, i.e. log base 1.0001 of the starting price of the pool
                              event Initialize(uint160 sqrtPriceX96, int24 tick);
                              /// @notice Emitted when liquidity is minted for a given position
                              /// @param sender The address that minted the liquidity
                              /// @param owner The owner of the position and recipient of any minted liquidity
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount The amount of liquidity minted to the position range
                              /// @param amount0 How much token0 was required for the minted liquidity
                              /// @param amount1 How much token1 was required for the minted liquidity
                              event Mint(
                                  address sender,
                                  address indexed owner,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount,
                                  uint256 amount0,
                                  uint256 amount1
                              );
                              /// @notice Emitted when fees are collected by the owner of a position
                              /// @dev Collect events may be emitted with zero amount0 and amount1 when the caller chooses not to collect fees
                              /// @param owner The owner of the position for which fees are collected
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount0 The amount of token0 fees collected
                              /// @param amount1 The amount of token1 fees collected
                              event Collect(
                                  address indexed owner,
                                  address recipient,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount0,
                                  uint128 amount1
                              );
                              /// @notice Emitted when a position's liquidity is removed
                              /// @dev Does not withdraw any fees earned by the liquidity position, which must be withdrawn via #collect
                              /// @param owner The owner of the position for which liquidity is removed
                              /// @param tickLower The lower tick of the position
                              /// @param tickUpper The upper tick of the position
                              /// @param amount The amount of liquidity to remove
                              /// @param amount0 The amount of token0 withdrawn
                              /// @param amount1 The amount of token1 withdrawn
                              event Burn(
                                  address indexed owner,
                                  int24 indexed tickLower,
                                  int24 indexed tickUpper,
                                  uint128 amount,
                                  uint256 amount0,
                                  uint256 amount1
                              );
                              /// @notice Emitted by the pool for any swaps between token0 and token1
                              /// @param sender The address that initiated the swap call, and that received the callback
                              /// @param recipient The address that received the output of the swap
                              /// @param amount0 The delta of the token0 balance of the pool
                              /// @param amount1 The delta of the token1 balance of the pool
                              /// @param sqrtPriceX96 The sqrt(price) of the pool after the swap, as a Q64.96
                              /// @param liquidity The liquidity of the pool after the swap
                              /// @param tick The log base 1.0001 of price of the pool after the swap
                              event Swap(
                                  address indexed sender,
                                  address indexed recipient,
                                  int256 amount0,
                                  int256 amount1,
                                  uint160 sqrtPriceX96,
                                  uint128 liquidity,
                                  int24 tick
                              );
                              /// @notice Emitted by the pool for any flashes of token0/token1
                              /// @param sender The address that initiated the swap call, and that received the callback
                              /// @param recipient The address that received the tokens from flash
                              /// @param amount0 The amount of token0 that was flashed
                              /// @param amount1 The amount of token1 that was flashed
                              /// @param paid0 The amount of token0 paid for the flash, which can exceed the amount0 plus the fee
                              /// @param paid1 The amount of token1 paid for the flash, which can exceed the amount1 plus the fee
                              event Flash(
                                  address indexed sender,
                                  address indexed recipient,
                                  uint256 amount0,
                                  uint256 amount1,
                                  uint256 paid0,
                                  uint256 paid1
                              );
                              /// @notice Emitted by the pool for increases to the number of observations that can be stored
                              /// @dev observationCardinalityNext is not the observation cardinality until an observation is written at the index
                              /// just before a mint/swap/burn.
                              /// @param observationCardinalityNextOld The previous value of the next observation cardinality
                              /// @param observationCardinalityNextNew The updated value of the next observation cardinality
                              event IncreaseObservationCardinalityNext(
                                  uint16 observationCardinalityNextOld,
                                  uint16 observationCardinalityNextNew
                              );
                              /// @notice Emitted when the protocol fee is changed by the pool
                              /// @param feeProtocol0Old The previous value of the token0 protocol fee
                              /// @param feeProtocol1Old The previous value of the token1 protocol fee
                              /// @param feeProtocol0New The updated value of the token0 protocol fee
                              /// @param feeProtocol1New The updated value of the token1 protocol fee
                              event SetFeeProtocol(uint8 feeProtocol0Old, uint8 feeProtocol1Old, uint8 feeProtocol0New, uint8 feeProtocol1New);
                              /// @notice Emitted when the collected protocol fees are withdrawn by the factory owner
                              /// @param sender The address that collects the protocol fees
                              /// @param recipient The address that receives the collected protocol fees
                              /// @param amount0 The amount of token0 protocol fees that is withdrawn
                              /// @param amount0 The amount of token1 protocol fees that is withdrawn
                              event CollectProtocol(address indexed sender, address indexed recipient, uint128 amount0, uint128 amount1);
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title BitMath
                          /// @dev This library provides functionality for computing bit properties of an unsigned integer
                          library BitMath {
                              /// @notice Returns the index of the most significant bit of the number,
                              ///     where the least significant bit is at index 0 and the most significant bit is at index 255
                              /// @dev The function satisfies the property:
                              ///     x >= 2**mostSignificantBit(x) and x < 2**(mostSignificantBit(x)+1)
                              /// @param x the value for which to compute the most significant bit, must be greater than 0
                              /// @return r the index of the most significant bit
                              function mostSignificantBit(uint256 x) internal pure returns (uint8 r) {
                                  require(x > 0);
                                  if (x >= 0x100000000000000000000000000000000) {
                                      x >>= 128;
                                      r += 128;
                                  }
                                  if (x >= 0x10000000000000000) {
                                      x >>= 64;
                                      r += 64;
                                  }
                                  if (x >= 0x100000000) {
                                      x >>= 32;
                                      r += 32;
                                  }
                                  if (x >= 0x10000) {
                                      x >>= 16;
                                      r += 16;
                                  }
                                  if (x >= 0x100) {
                                      x >>= 8;
                                      r += 8;
                                  }
                                  if (x >= 0x10) {
                                      x >>= 4;
                                      r += 4;
                                  }
                                  if (x >= 0x4) {
                                      x >>= 2;
                                      r += 2;
                                  }
                                  if (x >= 0x2) r += 1;
                              }
                              /// @notice Returns the index of the least significant bit of the number,
                              ///     where the least significant bit is at index 0 and the most significant bit is at index 255
                              /// @dev The function satisfies the property:
                              ///     (x & 2**leastSignificantBit(x)) != 0 and (x & (2**(leastSignificantBit(x)) - 1)) == 0)
                              /// @param x the value for which to compute the least significant bit, must be greater than 0
                              /// @return r the index of the least significant bit
                              function leastSignificantBit(uint256 x) internal pure returns (uint8 r) {
                                  require(x > 0);
                                  r = 255;
                                  if (x & type(uint128).max > 0) {
                                      r -= 128;
                                  } else {
                                      x >>= 128;
                                  }
                                  if (x & type(uint64).max > 0) {
                                      r -= 64;
                                  } else {
                                      x >>= 64;
                                  }
                                  if (x & type(uint32).max > 0) {
                                      r -= 32;
                                  } else {
                                      x >>= 32;
                                  }
                                  if (x & type(uint16).max > 0) {
                                      r -= 16;
                                  } else {
                                      x >>= 16;
                                  }
                                  if (x & type(uint8).max > 0) {
                                      r -= 8;
                                  } else {
                                      x >>= 8;
                                  }
                                  if (x & 0xf > 0) {
                                      r -= 4;
                                  } else {
                                      x >>= 4;
                                  }
                                  if (x & 0x3 > 0) {
                                      r -= 2;
                                  } else {
                                      x >>= 2;
                                  }
                                  if (x & 0x1 > 0) r -= 1;
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.5.0;
                          /// @title Math functions that do not check inputs or outputs
                          /// @notice Contains methods that perform common math functions but do not do any overflow or underflow checks
                          library UnsafeMath {
                              /// @notice Returns ceil(x / y)
                              /// @dev division by 0 has unspecified behavior, and must be checked externally
                              /// @param x The dividend
                              /// @param y The divisor
                              /// @return z The quotient, ceil(x / y)
                              function divRoundingUp(uint256 x, uint256 y) internal pure returns (uint256 z) {
                                  assembly {
                                      z := add(div(x, y), gt(mod(x, y), 0))
                                  }
                              }
                          }
                          // SPDX-License-Identifier: GPL-2.0-or-later
                          pragma solidity >=0.4.0;
                          /// @title FixedPoint96
                          /// @notice A library for handling binary fixed point numbers, see https://en.wikipedia.org/wiki/Q_(number_format)
                          /// @dev Used in SqrtPriceMath.sol
                          library FixedPoint96 {
                              uint8 internal constant RESOLUTION = 96;
                              uint256 internal constant Q96 = 0x1000000000000000000000000;
                          }
                          

                          File 8 of 13: TetherToken
                          pragma solidity ^0.4.17;
                          
                          /**
                           * @title SafeMath
                           * @dev Math operations with safety checks that throw on error
                           */
                          library SafeMath {
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  if (a == 0) {
                                      return 0;
                                  }
                                  uint256 c = a * b;
                                  assert(c / a == b);
                                  return c;
                              }
                          
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // assert(b > 0); // Solidity automatically throws when dividing by 0
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                                  return c;
                              }
                          
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  assert(b <= a);
                                  return a - b;
                              }
                          
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  assert(c >= a);
                                  return c;
                              }
                          }
                          
                          /**
                           * @title Ownable
                           * @dev The Ownable contract has an owner address, and provides basic authorization control
                           * functions, this simplifies the implementation of "user permissions".
                           */
                          contract Ownable {
                              address public owner;
                          
                              /**
                                * @dev The Ownable constructor sets the original `owner` of the contract to the sender
                                * account.
                                */
                              function Ownable() public {
                                  owner = msg.sender;
                              }
                          
                              /**
                                * @dev Throws if called by any account other than the owner.
                                */
                              modifier onlyOwner() {
                                  require(msg.sender == owner);
                                  _;
                              }
                          
                              /**
                              * @dev Allows the current owner to transfer control of the contract to a newOwner.
                              * @param newOwner The address to transfer ownership to.
                              */
                              function transferOwnership(address newOwner) public onlyOwner {
                                  if (newOwner != address(0)) {
                                      owner = newOwner;
                                  }
                              }
                          
                          }
                          
                          /**
                           * @title ERC20Basic
                           * @dev Simpler version of ERC20 interface
                           * @dev see https://github.com/ethereum/EIPs/issues/20
                           */
                          contract ERC20Basic {
                              uint public _totalSupply;
                              function totalSupply() public constant returns (uint);
                              function balanceOf(address who) public constant returns (uint);
                              function transfer(address to, uint value) public;
                              event Transfer(address indexed from, address indexed to, uint value);
                          }
                          
                          /**
                           * @title ERC20 interface
                           * @dev see https://github.com/ethereum/EIPs/issues/20
                           */
                          contract ERC20 is ERC20Basic {
                              function allowance(address owner, address spender) public constant returns (uint);
                              function transferFrom(address from, address to, uint value) public;
                              function approve(address spender, uint value) public;
                              event Approval(address indexed owner, address indexed spender, uint value);
                          }
                          
                          /**
                           * @title Basic token
                           * @dev Basic version of StandardToken, with no allowances.
                           */
                          contract BasicToken is Ownable, ERC20Basic {
                              using SafeMath for uint;
                          
                              mapping(address => uint) public balances;
                          
                              // additional variables for use if transaction fees ever became necessary
                              uint public basisPointsRate = 0;
                              uint public maximumFee = 0;
                          
                              /**
                              * @dev Fix for the ERC20 short address attack.
                              */
                              modifier onlyPayloadSize(uint size) {
                                  require(!(msg.data.length < size + 4));
                                  _;
                              }
                          
                              /**
                              * @dev transfer token for a specified address
                              * @param _to The address to transfer to.
                              * @param _value The amount to be transferred.
                              */
                              function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
                                  uint fee = (_value.mul(basisPointsRate)).div(10000);
                                  if (fee > maximumFee) {
                                      fee = maximumFee;
                                  }
                                  uint sendAmount = _value.sub(fee);
                                  balances[msg.sender] = balances[msg.sender].sub(_value);
                                  balances[_to] = balances[_to].add(sendAmount);
                                  if (fee > 0) {
                                      balances[owner] = balances[owner].add(fee);
                                      Transfer(msg.sender, owner, fee);
                                  }
                                  Transfer(msg.sender, _to, sendAmount);
                              }
                          
                              /**
                              * @dev Gets the balance of the specified address.
                              * @param _owner The address to query the the balance of.
                              * @return An uint representing the amount owned by the passed address.
                              */
                              function balanceOf(address _owner) public constant returns (uint balance) {
                                  return balances[_owner];
                              }
                          
                          }
                          
                          /**
                           * @title Standard ERC20 token
                           *
                           * @dev Implementation of the basic standard token.
                           * @dev https://github.com/ethereum/EIPs/issues/20
                           * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
                           */
                          contract StandardToken is BasicToken, ERC20 {
                          
                              mapping (address => mapping (address => uint)) public allowed;
                          
                              uint public constant MAX_UINT = 2**256 - 1;
                          
                              /**
                              * @dev Transfer tokens from one address to another
                              * @param _from address The address which you want to send tokens from
                              * @param _to address The address which you want to transfer to
                              * @param _value uint the amount of tokens to be transferred
                              */
                              function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
                                  var _allowance = allowed[_from][msg.sender];
                          
                                  // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
                                  // if (_value > _allowance) throw;
                          
                                  uint fee = (_value.mul(basisPointsRate)).div(10000);
                                  if (fee > maximumFee) {
                                      fee = maximumFee;
                                  }
                                  if (_allowance < MAX_UINT) {
                                      allowed[_from][msg.sender] = _allowance.sub(_value);
                                  }
                                  uint sendAmount = _value.sub(fee);
                                  balances[_from] = balances[_from].sub(_value);
                                  balances[_to] = balances[_to].add(sendAmount);
                                  if (fee > 0) {
                                      balances[owner] = balances[owner].add(fee);
                                      Transfer(_from, owner, fee);
                                  }
                                  Transfer(_from, _to, sendAmount);
                              }
                          
                              /**
                              * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
                              * @param _spender The address which will spend the funds.
                              * @param _value The amount of tokens to be spent.
                              */
                              function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
                          
                                  // To change the approve amount you first have to reduce the addresses`
                                  //  allowance to zero by calling `approve(_spender, 0)` if it is not
                                  //  already 0 to mitigate the race condition described here:
                                  //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                                  require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
                          
                                  allowed[msg.sender][_spender] = _value;
                                  Approval(msg.sender, _spender, _value);
                              }
                          
                              /**
                              * @dev Function to check the amount of tokens than an owner allowed to a spender.
                              * @param _owner address The address which owns the funds.
                              * @param _spender address The address which will spend the funds.
                              * @return A uint specifying the amount of tokens still available for the spender.
                              */
                              function allowance(address _owner, address _spender) public constant returns (uint remaining) {
                                  return allowed[_owner][_spender];
                              }
                          
                          }
                          
                          
                          /**
                           * @title Pausable
                           * @dev Base contract which allows children to implement an emergency stop mechanism.
                           */
                          contract Pausable is Ownable {
                            event Pause();
                            event Unpause();
                          
                            bool public paused = false;
                          
                          
                            /**
                             * @dev Modifier to make a function callable only when the contract is not paused.
                             */
                            modifier whenNotPaused() {
                              require(!paused);
                              _;
                            }
                          
                            /**
                             * @dev Modifier to make a function callable only when the contract is paused.
                             */
                            modifier whenPaused() {
                              require(paused);
                              _;
                            }
                          
                            /**
                             * @dev called by the owner to pause, triggers stopped state
                             */
                            function pause() onlyOwner whenNotPaused public {
                              paused = true;
                              Pause();
                            }
                          
                            /**
                             * @dev called by the owner to unpause, returns to normal state
                             */
                            function unpause() onlyOwner whenPaused public {
                              paused = false;
                              Unpause();
                            }
                          }
                          
                          contract BlackList is Ownable, BasicToken {
                          
                              /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
                              function getBlackListStatus(address _maker) external constant returns (bool) {
                                  return isBlackListed[_maker];
                              }
                          
                              function getOwner() external constant returns (address) {
                                  return owner;
                              }
                          
                              mapping (address => bool) public isBlackListed;
                              
                              function addBlackList (address _evilUser) public onlyOwner {
                                  isBlackListed[_evilUser] = true;
                                  AddedBlackList(_evilUser);
                              }
                          
                              function removeBlackList (address _clearedUser) public onlyOwner {
                                  isBlackListed[_clearedUser] = false;
                                  RemovedBlackList(_clearedUser);
                              }
                          
                              function destroyBlackFunds (address _blackListedUser) public onlyOwner {
                                  require(isBlackListed[_blackListedUser]);
                                  uint dirtyFunds = balanceOf(_blackListedUser);
                                  balances[_blackListedUser] = 0;
                                  _totalSupply -= dirtyFunds;
                                  DestroyedBlackFunds(_blackListedUser, dirtyFunds);
                              }
                          
                              event DestroyedBlackFunds(address _blackListedUser, uint _balance);
                          
                              event AddedBlackList(address _user);
                          
                              event RemovedBlackList(address _user);
                          
                          }
                          
                          contract UpgradedStandardToken is StandardToken{
                              // those methods are called by the legacy contract
                              // and they must ensure msg.sender to be the contract address
                              function transferByLegacy(address from, address to, uint value) public;
                              function transferFromByLegacy(address sender, address from, address spender, uint value) public;
                              function approveByLegacy(address from, address spender, uint value) public;
                          }
                          
                          contract TetherToken is Pausable, StandardToken, BlackList {
                          
                              string public name;
                              string public symbol;
                              uint public decimals;
                              address public upgradedAddress;
                              bool public deprecated;
                          
                              //  The contract can be initialized with a number of tokens
                              //  All the tokens are deposited to the owner address
                              //
                              // @param _balance Initial supply of the contract
                              // @param _name Token Name
                              // @param _symbol Token symbol
                              // @param _decimals Token decimals
                              function TetherToken(uint _initialSupply, string _name, string _symbol, uint _decimals) public {
                                  _totalSupply = _initialSupply;
                                  name = _name;
                                  symbol = _symbol;
                                  decimals = _decimals;
                                  balances[owner] = _initialSupply;
                                  deprecated = false;
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function transfer(address _to, uint _value) public whenNotPaused {
                                  require(!isBlackListed[msg.sender]);
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
                                  } else {
                                      return super.transfer(_to, _value);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
                                  require(!isBlackListed[_from]);
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
                                  } else {
                                      return super.transferFrom(_from, _to, _value);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function balanceOf(address who) public constant returns (uint) {
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).balanceOf(who);
                                  } else {
                                      return super.balanceOf(who);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
                                  if (deprecated) {
                                      return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
                                  } else {
                                      return super.approve(_spender, _value);
                                  }
                              }
                          
                              // Forward ERC20 methods to upgraded contract if this one is deprecated
                              function allowance(address _owner, address _spender) public constant returns (uint remaining) {
                                  if (deprecated) {
                                      return StandardToken(upgradedAddress).allowance(_owner, _spender);
                                  } else {
                                      return super.allowance(_owner, _spender);
                                  }
                              }
                          
                              // deprecate current contract in favour of a new one
                              function deprecate(address _upgradedAddress) public onlyOwner {
                                  deprecated = true;
                                  upgradedAddress = _upgradedAddress;
                                  Deprecate(_upgradedAddress);
                              }
                          
                              // deprecate current contract if favour of a new one
                              function totalSupply() public constant returns (uint) {
                                  if (deprecated) {
                                      return StandardToken(upgradedAddress).totalSupply();
                                  } else {
                                      return _totalSupply;
                                  }
                              }
                          
                              // Issue a new amount of tokens
                              // these tokens are deposited into the owner address
                              //
                              // @param _amount Number of tokens to be issued
                              function issue(uint amount) public onlyOwner {
                                  require(_totalSupply + amount > _totalSupply);
                                  require(balances[owner] + amount > balances[owner]);
                          
                                  balances[owner] += amount;
                                  _totalSupply += amount;
                                  Issue(amount);
                              }
                          
                              // Redeem tokens.
                              // These tokens are withdrawn from the owner address
                              // if the balance must be enough to cover the redeem
                              // or the call will fail.
                              // @param _amount Number of tokens to be issued
                              function redeem(uint amount) public onlyOwner {
                                  require(_totalSupply >= amount);
                                  require(balances[owner] >= amount);
                          
                                  _totalSupply -= amount;
                                  balances[owner] -= amount;
                                  Redeem(amount);
                              }
                          
                              function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
                                  // Ensure transparency by hardcoding limit beyond which fees can never be added
                                  require(newBasisPoints < 20);
                                  require(newMaxFee < 50);
                          
                                  basisPointsRate = newBasisPoints;
                                  maximumFee = newMaxFee.mul(10**decimals);
                          
                                  Params(basisPointsRate, maximumFee);
                              }
                          
                              // Called when new token are issued
                              event Issue(uint amount);
                          
                              // Called when tokens are redeemed
                              event Redeem(uint amount);
                          
                              // Called when contract is deprecated
                              event Deprecate(address newAddress);
                          
                              // Called if contract ever adds fees
                              event Params(uint feeBasisPoints, uint maxFee);
                          }

                          File 9 of 13: UserProxy
                          // SPDX-License-Identifier: MIT
                          pragma solidity 0.7.6;
                          pragma abicoder v2;
                          import "./utils/UserProxyStorage.sol";
                          import "./utils/Multicall.sol";
                          /**
                           * @dev UserProxy contract
                           */
                          contract UserProxy is Multicall {
                              // Below are the variables which consume storage slots.
                              address public operator;
                              string public version; // Current version of the contract
                              address private nominatedOperator;
                              // Operator events
                              event OperatorNominated(address indexed newOperator);
                              event OperatorChanged(address indexed oldOperator, address indexed newOperator);
                              event SetAMMStatus(bool enable);
                              event UpgradeAMMWrapper(address newAMMWrapper);
                              event SetPMMStatus(bool enable);
                              event UpgradePMM(address newPMM);
                              event SetRFQStatus(bool enable);
                              event UpgradeRFQ(address newRFQ);
                              event SetRFQv2Status(bool enable);
                              event UpgradeRFQv2(address newRFQv2);
                              event SetLimitOrderStatus(bool enable);
                              event UpgradeLimitOrder(address newLimitOrder);
                              receive() external payable {}
                              /************************************************************
                               *          Access control and ownership management          *
                               *************************************************************/
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "UserProxy: not the operator");
                                  _;
                              }
                              function nominateNewOperator(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "UserProxy: operator can not be zero address");
                                  nominatedOperator = _newOperator;
                                  emit OperatorNominated(_newOperator);
                              }
                              function acceptOwnership() external {
                                  require(msg.sender == nominatedOperator, "UserProxy: not nominated");
                                  emit OperatorChanged(operator, nominatedOperator);
                                  operator = nominatedOperator;
                                  nominatedOperator = address(0);
                              }
                              /************************************************************
                               *              Constructor and init functions               *
                               *************************************************************/
                              /// @dev Replacing constructor and initialize the contract. This function should only be called once.
                              function initialize(address _operator) external {
                                  require(keccak256(abi.encodePacked(version)) == keccak256(abi.encodePacked("")), "UserProxy: not upgrading from empty");
                                  require(_operator != address(0), "UserProxy: operator can not be zero address");
                                  operator = _operator;
                                  // Upgrade version
                                  version = "5.3.0";
                              }
                              /************************************************************
                               *                     Getter functions                      *
                               *************************************************************/
                              function ammWrapperAddr() public view returns (address) {
                                  return AMMWrapperStorage.getStorage().ammWrapperAddr;
                              }
                              function isAMMEnabled() public view returns (bool) {
                                  return AMMWrapperStorage.getStorage().isEnabled;
                              }
                              function pmmAddr() public view returns (address) {
                                  return PMMStorage.getStorage().pmmAddr;
                              }
                              function isPMMEnabled() public view returns (bool) {
                                  return PMMStorage.getStorage().isEnabled;
                              }
                              function rfqAddr() public view returns (address) {
                                  return RFQStorage.getStorage().rfqAddr;
                              }
                              function isRFQEnabled() public view returns (bool) {
                                  return RFQStorage.getStorage().isEnabled;
                              }
                              function rfqv2Addr() public view returns (address) {
                                  return RFQv2Storage.getStorage().rfqv2Addr;
                              }
                              function isRFQv2Enabled() public view returns (bool) {
                                  return RFQv2Storage.getStorage().isEnabled;
                              }
                              function limitOrderAddr() public view returns (address) {
                                  return LimitOrderStorage.getStorage().limitOrderAddr;
                              }
                              function isLimitOrderEnabled() public view returns (bool) {
                                  return LimitOrderStorage.getStorage().isEnabled;
                              }
                              /************************************************************
                               *           Management functions for Operator               *
                               *************************************************************/
                              function setAMMStatus(bool _enable) public onlyOperator {
                                  AMMWrapperStorage.getStorage().isEnabled = _enable;
                                  emit SetAMMStatus(_enable);
                              }
                              function upgradeAMMWrapper(address _newAMMWrapperAddr, bool _enable) external onlyOperator {
                                  AMMWrapperStorage.getStorage().ammWrapperAddr = _newAMMWrapperAddr;
                                  AMMWrapperStorage.getStorage().isEnabled = _enable;
                                  emit UpgradeAMMWrapper(_newAMMWrapperAddr);
                                  emit SetAMMStatus(_enable);
                              }
                              function setPMMStatus(bool _enable) public onlyOperator {
                                  PMMStorage.getStorage().isEnabled = _enable;
                                  emit SetPMMStatus(_enable);
                              }
                              function upgradePMM(address _newPMMAddr, bool _enable) external onlyOperator {
                                  PMMStorage.getStorage().pmmAddr = _newPMMAddr;
                                  PMMStorage.getStorage().isEnabled = _enable;
                                  emit UpgradePMM(_newPMMAddr);
                                  emit SetPMMStatus(_enable);
                              }
                              function setRFQStatus(bool _enable) public onlyOperator {
                                  RFQStorage.getStorage().isEnabled = _enable;
                                  emit SetRFQStatus(_enable);
                              }
                              function upgradeRFQ(address _newRFQAddr, bool _enable) external onlyOperator {
                                  RFQStorage.getStorage().rfqAddr = _newRFQAddr;
                                  RFQStorage.getStorage().isEnabled = _enable;
                                  emit UpgradeRFQ(_newRFQAddr);
                                  emit SetRFQStatus(_enable);
                              }
                              function setRFQv2Status(bool _enable) public onlyOperator {
                                  RFQv2Storage.getStorage().isEnabled = _enable;
                                  emit SetRFQv2Status(_enable);
                              }
                              function upgradeRFQv2(address _newRFQv2Addr, bool _enable) external onlyOperator {
                                  RFQv2Storage.getStorage().rfqv2Addr = _newRFQv2Addr;
                                  RFQv2Storage.getStorage().isEnabled = _enable;
                                  emit UpgradeRFQv2(_newRFQv2Addr);
                                  emit SetRFQv2Status(_enable);
                              }
                              function setLimitOrderStatus(bool _enable) public onlyOperator {
                                  LimitOrderStorage.getStorage().isEnabled = _enable;
                                  emit SetLimitOrderStatus(_enable);
                              }
                              function upgradeLimitOrder(address _newLimitOrderAddr, bool _enable) external onlyOperator {
                                  LimitOrderStorage.getStorage().limitOrderAddr = _newLimitOrderAddr;
                                  LimitOrderStorage.getStorage().isEnabled = _enable;
                                  emit UpgradeLimitOrder(_newLimitOrderAddr);
                                  emit SetLimitOrderStatus(_enable);
                              }
                              /************************************************************
                               *                   External functions                      *
                               *************************************************************/
                              /**
                               * @dev proxy the call to AMM
                               */
                              function toAMM(bytes calldata _payload) external payable {
                                  require(isAMMEnabled(), "UserProxy: AMM is disabled");
                                  (bool callSucceed, ) = ammWrapperAddr().call{ value: msg.value }(_payload);
                                  if (!callSucceed) {
                                      // revert with data from last call
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                              /**
                               * @dev proxy the call to PMM
                               */
                              function toPMM(bytes calldata _payload) external payable {
                                  require(isPMMEnabled(), "UserProxy: PMM is disabled");
                                  require(msg.sender == tx.origin, "UserProxy: only EOA");
                                  (bool callSucceed, ) = pmmAddr().call{ value: msg.value }(_payload);
                                  if (!callSucceed) {
                                      // revert with data from last call
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                              /**
                               * @dev proxy the call to RFQ
                               */
                              function toRFQ(bytes calldata _payload) external payable {
                                  require(isRFQEnabled(), "UserProxy: RFQ is disabled");
                                  require(msg.sender == tx.origin, "UserProxy: only EOA");
                                  (bool callSucceed, ) = rfqAddr().call{ value: msg.value }(_payload);
                                  if (!callSucceed) {
                                      // revert with data from last call
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                              /**
                               * @dev proxy the call to RFQv2
                               */
                              function toRFQv2(bytes calldata _payload) external payable {
                                  require(isRFQv2Enabled(), "UserProxy: RFQv2 is disabled");
                                  require(msg.sender == tx.origin, "UserProxy: only EOA");
                                  (bool callSucceed, ) = rfqv2Addr().call{ value: msg.value }(_payload);
                                  if (!callSucceed) {
                                      // revert with data from last call
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                              /**
                               * @dev proxy the call to Limit Order
                               */
                              function toLimitOrder(bytes calldata _payload) external {
                                  require(isLimitOrderEnabled(), "UserProxy: Limit Order is disabled");
                                  require(msg.sender == tx.origin, "UserProxy: only EOA");
                                  (bool callSucceed, ) = limitOrderAddr().call(_payload);
                                  if (!callSucceed) {
                                      // revert with data from last call
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.7.6;
                          library AMMWrapperStorage {
                              bytes32 private constant STORAGE_SLOT = 0xbf49677e3150252dfa801a673d2d5ec21eaa360a4674864e55e79041e3f65a6b;
                              /// @dev Storage bucket for proxy contract.
                              struct Storage {
                                  // The address of the AMMWrapper contract.
                                  address ammWrapperAddr;
                                  // Is AMM enabled
                                  bool isEnabled;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("userproxy.ammwrapper.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library PMMStorage {
                              bytes32 private constant STORAGE_SLOT = 0x8f135983375ba6442123d61647e7325c1753eabc2e038e44d3b888a970def89a;
                              /// @dev Storage bucket for proxy contract.
                              struct Storage {
                                  // The address of the PMM contract.
                                  address pmmAddr;
                                  // Is PMM enabled
                                  bool isEnabled;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("userproxy.pmm.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library RFQStorage {
                              bytes32 private constant STORAGE_SLOT = 0x857df08bd185dc66e3cc5e11acb4e1dd65290f3fee6426f52f84e8faccf229cf;
                              /// @dev Storage bucket for proxy contract.
                              struct Storage {
                                  // The address of the RFQ contract.
                                  address rfqAddr;
                                  // Is RFQ enabled
                                  bool isEnabled;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("userproxy.rfq.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library RFQv2Storage {
                              bytes32 private constant STORAGE_SLOT = 0xd5f1768ede616e352f32123fd6fe01064898ae4e55a2678c79b8ad79680ff744;
                              /// @dev Storage bucket for proxy contract.
                              struct Storage {
                                  // The address of the RFQv2 contract.
                                  address rfqv2Addr;
                                  // Is RFQv2 enabled
                                  bool isEnabled;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("userproxy.rfqv2.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library LimitOrderStorage {
                              bytes32 private constant STORAGE_SLOT = 0xf1a59a985b4002cdf0db464f05bed7182ee06372a999d820ea1883b8bf067ce5;
                              /// @dev Storage bucket for proxy contract.
                              struct Storage {
                                  // The address of the Limit Order contract.
                                  address limitOrderAddr;
                                  // Is Limit Order enabled
                                  bool isEnabled;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("userproxy.limitorder.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity 0.7.6;
                          pragma abicoder v2;
                          import "../interfaces/IMulticall.sol";
                          // Modified from https://github.com/Uniswap/uniswap-v3-periphery/blob/v1.1.1/contracts/base/Multicall.sol
                          abstract contract Multicall is IMulticall {
                              function multicall(bytes[] calldata data, bool revertOnFail) external override returns (bool[] memory successes, bytes[] memory results) {
                                  successes = new bool[](data.length);
                                  results = new bytes[](data.length);
                                  for (uint256 i = 0; i < data.length; ++i) {
                                      (bool success, bytes memory result) = address(this).delegatecall(data[i]);
                                      successes[i] = success;
                                      results[i] = result;
                                      if (!success) {
                                          // Get failed reason
                                          string memory revertReason;
                                          if (result.length < 68) {
                                              revertReason = "Delegatecall failed";
                                          } else {
                                              assembly {
                                                  result := add(result, 0x04)
                                              }
                                              revertReason = abi.decode(result, (string));
                                          }
                                          if (revertOnFail) {
                                              revert(revertReason);
                                          }
                                          emit MulticallFailure(i, revertReason);
                                      }
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.7.0;
                          pragma abicoder v2;
                          interface IMulticall {
                              event MulticallFailure(uint256 index, string reason);
                              function multicall(bytes[] calldata data, bool revertOnFail) external returns (bool[] memory successes, bytes[] memory results);
                          }
                          

                          File 10 of 13: TransparentUpgradeableProxy
                          // SPDX-License-Identifier: MIT
                          // File: @openzeppelin/contracts/utils/Address.sol
                          pragma solidity ^0.6.2;
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev Returns true if `account` is a contract.
                               *
                               * [IMPORTANT]
                               * ====
                               * It is unsafe to assume that an address for which this function returns
                               * false is an externally-owned account (EOA) and not a contract.
                               *
                               * Among others, `isContract` will return false for the following
                               * types of addresses:
                               *
                               *  - an externally-owned account
                               *  - a contract in construction
                               *  - an address where a contract will be created
                               *  - an address where a contract lived, but was destroyed
                               * ====
                               */
                              function isContract(address account) internal view returns (bool) {
                                  // This method relies in extcodesize, which returns 0 for contracts in
                                  // construction, since the code is only stored at the end of the
                                  // constructor execution.
                                  uint256 size;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { size := extcodesize(account) }
                                  return size > 0;
                              }
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  require(address(this).balance >= amount, "Address: insufficient balance");
                                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                  (bool success, ) = recipient.call{ value: amount }("");
                                  require(success, "Address: unable to send value, recipient may have reverted");
                              }
                              /**
                               * @dev Performs a Solidity function call using a low level `call`. A
                               * plain`call` is an unsafe replacement for a function call: use this
                               * function instead.
                               *
                               * If `target` reverts with a revert reason, it is bubbled up by this
                               * function (like regular Solidity function calls).
                               *
                               * Returns the raw returned data. To convert to the expected return value,
                               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                               *
                               * Requirements:
                               *
                               * - `target` must be a contract.
                               * - calling `target` with `data` must not revert.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                return functionCall(target, data, "Address: low-level call failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                               * `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  return _functionCallWithValue(target, data, 0, errorMessage);
                              }
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but also transferring `value` wei to `target`.
                               *
                               * Requirements:
                               *
                               * - the calling contract must have an ETH balance of at least `value`.
                               * - the called Solidity function must be `payable`.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                              }
                              /**
                               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                               * with `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                  require(address(this).balance >= value, "Address: insufficient balance for call");
                                  return _functionCallWithValue(target, data, value, errorMessage);
                              }
                              function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
                                  require(isContract(target), "Address: call to non-contract");
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
                                  if (success) {
                                      return returndata;
                                  } else {
                                      // Look for revert reason and bubble it up if present
                                      if (returndata.length > 0) {
                                          // The easiest way to bubble the revert reason is using memory via assembly
                                          // solhint-disable-next-line no-inline-assembly
                                          assembly {
                                              let returndata_size := mload(returndata)
                                              revert(add(32, returndata), returndata_size)
                                          }
                                      } else {
                                          revert(errorMessage);
                                      }
                                  }
                              }
                          }
                          // File: contracts/upgrade_proxy/Proxy.sol
                          pragma solidity ^0.6.0;
                          /**
                           * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                           * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                           * be specified by overriding the virtual {_implementation} function.
                           * 
                           * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                           * different contract through the {_delegate} function.
                           * 
                           * The success and return data of the delegated call will be returned back to the caller of the proxy.
                           */
                          abstract contract Proxy {
                              /**
                               * @dev Delegates the current call to `implementation`.
                               * 
                               * This function does not return to its internall call site, it will return directly to the external caller.
                               */
                              function _delegate(address implementation) internal {
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      // Copy msg.data. We take full control of memory in this inline assembly
                                      // block because it will not return to Solidity code. We overwrite the
                                      // Solidity scratch pad at memory position 0.
                                      calldatacopy(0, 0, calldatasize())
                                      // Call the implementation.
                                      // out and outsize are 0 because we don't know the size yet.
                                      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                      // Copy the returned data.
                                      returndatacopy(0, 0, returndatasize())
                                      switch result
                                      // delegatecall returns 0 on error.
                                      case 0 { revert(0, returndatasize()) }
                                      default { return(0, returndatasize()) }
                                  }
                              }
                              /**
                               * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                               * and {_fallback} should delegate.
                               */
                              function _implementation() internal virtual view returns (address);
                              /**
                               * @dev Delegates the current call to the address returned by `_implementation()`.
                               * 
                               * This function does not return to its internall call site, it will return directly to the external caller.
                               */
                              function _fallback() internal {
                                  _beforeFallback();
                                  _delegate(_implementation());
                              }
                              /**
                               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                               * function in the contract matches the call data.
                               */
                              fallback () payable external {
                                  _fallback();
                              }
                              /**
                               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                               * is empty.
                               */
                              receive () payable external {
                                  _fallback();
                              }
                              /**
                               * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                               * call, or as part of the Solidity `fallback` or `receive` functions.
                               * 
                               * If overriden should call `super._beforeFallback()`.
                               */
                              function _beforeFallback() internal virtual {
                              }
                          }
                          // File: contracts/upgrade_proxy/UpgradeableProxy.sol
                          pragma solidity ^0.6.0;
                          /**
                           * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                           * implementation address that can be changed. This address is stored in storage in the location specified by
                           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                           * implementation behind the proxy.
                           * 
                           * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see
                           * {TransparentUpgradeableProxy}.
                           */
                          contract UpgradeableProxy is Proxy {
                              /**
                               * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                               * 
                               * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                               * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                               */
                              constructor(address _logic, bytes memory _data) public payable {
                                  assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                  _setImplementation(_logic);
                                  if(_data.length > 0) {
                                      // solhint-disable-next-line avoid-low-level-calls
                                      (bool success,) = _logic.delegatecall(_data);
                                      require(success);
                                  }
                              }
                              /**
                               * @dev Emitted when the implementation is upgraded.
                               */
                              event Upgraded(address indexed implementation);
                              /**
                               * @dev Storage slot with the address of the current implementation.
                               * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                               * validated in the constructor.
                               */
                              bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                              /**
                               * @dev Returns the current implementation address.
                               */
                              function _implementation() internal override view returns (address impl) {
                                  bytes32 slot = _IMPLEMENTATION_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      impl := sload(slot)
                                  }
                              }
                              /**
                               * @dev Upgrades the proxy to a new implementation.
                               * 
                               * Emits an {Upgraded} event.
                               */
                              function _upgradeTo(address newImplementation) internal {
                                  _setImplementation(newImplementation);
                                  emit Upgraded(newImplementation);
                              }
                              /**
                               * @dev Stores a new address in the EIP1967 implementation slot.
                               */
                              function _setImplementation(address newImplementation) private {
                                  require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");
                                  bytes32 slot = _IMPLEMENTATION_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      sstore(slot, newImplementation)
                                  }
                              }
                          }
                          // File: contracts/upgrade_proxy/TransparentUpgradeableProxy.sol
                          pragma solidity ^0.6.0;
                          /**
                           * @dev This contract implements a proxy that is upgradeable by an admin.
                           * 
                           * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
                           * clashing], which can potentially be used in an attack, this contract uses the
                           * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
                           * things that go hand in hand:
                           * 
                           * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
                           * that call matches one of the admin functions exposed by the proxy itself.
                           * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
                           * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
                           * "admin cannot fallback to proxy target".
                           * 
                           * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
                           * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
                           * to sudden errors when trying to call a function from the proxy implementation.
                           * 
                           * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
                           * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
                           */
                          contract TransparentUpgradeableProxy is UpgradeableProxy {
                              /**
                               * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
                               * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}.
                               */
                              constructor(address _logic, address _admin, bytes memory _data) public payable UpgradeableProxy(_logic, _data) {
                                  assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                                  _setAdmin(_admin);
                              }
                              /**
                               * @dev Emitted when the admin account has changed.
                               */
                              event AdminChanged(address previousAdmin, address newAdmin);
                              /**
                               * @dev Storage slot with the admin of the contract.
                               * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                               * validated in the constructor.
                               */
                              bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                              /**
                               * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
                               */
                              modifier ifAdmin() {
                                  if (msg.sender == _admin()) {
                                      _;
                                  } else {
                                      _fallback();
                                  }
                              }
                              /**
                               * @dev Returns the current admin.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
                               * 
                               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                               * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
                               */
                              function admin() external ifAdmin returns (address) {
                                  return _admin();
                              }
                              /**
                               * @dev Returns the current implementation.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
                               * 
                               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
                               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
                               * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
                               */
                              function implementation() external ifAdmin returns (address) {
                                  return _implementation();
                              }
                              /**
                               * @dev Changes the admin of the proxy.
                               * 
                               * Emits an {AdminChanged} event.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
                               */
                              function changeAdmin(address newAdmin) external ifAdmin {
                                  require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
                                  emit AdminChanged(_admin(), newAdmin);
                                  _setAdmin(newAdmin);
                              }
                              /**
                               * @dev Upgrade the implementation of the proxy.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
                               */
                              function upgradeTo(address newImplementation) external ifAdmin {
                                  _upgradeTo(newImplementation);
                              }
                              /**
                               * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
                               * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
                               * proxied contract.
                               * 
                               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
                               */
                              function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                                  _upgradeTo(newImplementation);
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success,) = newImplementation.delegatecall(data);
                                  require(success);
                              }
                              /**
                               * @dev Returns the current admin.
                               */
                              function _admin() internal view returns (address adm) {
                                  bytes32 slot = _ADMIN_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      adm := sload(slot)
                                  }
                              }
                              /**
                               * @dev Stores a new address in the EIP1967 admin slot.
                               */
                              function _setAdmin(address newAdmin) private {
                                  bytes32 slot = _ADMIN_SLOT;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly {
                                      sstore(slot, newAdmin)
                                  }
                              }
                              /**
                               * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
                               */
                              function _beforeFallback() internal override virtual {
                                  require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                                  super._beforeFallback();
                              }
                          }

                          File 11 of 13: PermanentStorage
                          // SPDX-License-Identifier: MIT
                          pragma solidity 0.7.6;
                          import "./interfaces/IPermanentStorage.sol";
                          import "./utils/PSStorage.sol";
                          contract PermanentStorage is IPermanentStorage {
                              // Constants do not have storage slot.
                              bytes32 public constant curveTokenIndexStorageId = 0xf4c750cdce673f6c35898d215e519b86e3846b1f0532fb48b84fe9d80f6de2fc; // keccak256("curveTokenIndex")
                              bytes32 public constant transactionSeenStorageId = 0x695d523b8578c6379a2121164fd8de334b9c5b6b36dff5408bd4051a6b1704d0; // keccak256("transactionSeen")
                              bytes32 public constant relayerValidStorageId = 0x2c97779b4deaf24e9d46e02ec2699240a957d92782b51165b93878b09dd66f61; // keccak256("relayerValid")
                              bytes32 public constant allowFillSeenStorageId = 0x808188d002c47900fbb4e871d29754afff429009f6684806712612d807395dd8; // keccak256("allowFillSeen")
                              // New supported Curve pools
                              address public constant CURVE_renBTC_POOL = 0x93054188d876f558f4a66B2EF1d97d16eDf0895B;
                              address public constant CURVE_sBTC_POOL = 0x7fC77b5c7614E1533320Ea6DDc2Eb61fa00A9714;
                              address public constant CURVE_hBTC_POOL = 0x4CA9b3063Ec5866A4B82E437059D2C43d1be596F;
                              address public constant CURVE_sETH_POOL = 0xc5424B857f758E906013F3555Dad202e4bdB4567;
                              // Curve coins
                              address private constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant renBTC = 0xEB4C2781e4ebA804CE9a9803C67d0893436bB27D;
                              address private constant wBTC = 0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599;
                              address private constant sBTC = 0xfE18be6b3Bd88A2D2A7f928d00292E7a9963CfC6;
                              address private constant hBTC = 0x0316EB71485b0Ab14103307bf65a021042c6d380;
                              address private constant sETH = 0x5e74C9036fb86BD7eCdcb084a0673EFc32eA31cb;
                              // Below are the variables which consume storage slots.
                              address public operator;
                              string public version; // Current version of the contract
                              mapping(bytes32 => mapping(address => bool)) private permission;
                              address private nominatedOperator;
                              /************************************************************
                               *          Access control and ownership management          *
                               *************************************************************/
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "PermanentStorage: not the operator");
                                  _;
                              }
                              modifier isPermitted(bytes32 _storageId, address _role) {
                                  require(permission[_storageId][_role], "PermanentStorage: has no permission");
                                  _;
                              }
                              function nominateNewOperator(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "PermanentStorage: operator can not be zero address");
                                  nominatedOperator = _newOperator;
                                  emit OperatorNominated(_newOperator);
                              }
                              function acceptOwnership() external {
                                  require(msg.sender == nominatedOperator, "PermanentStorage: not nominated");
                                  emit OperatorChanged(operator, nominatedOperator);
                                  operator = nominatedOperator;
                                  nominatedOperator = address(0);
                              }
                              /// @dev Set permission for entity to write certain storage.
                              function setPermission(
                                  bytes32 _storageId,
                                  address _role,
                                  bool _enabled
                              ) external onlyOperator {
                                  if (_enabled) {
                                      require(
                                          (_role == operator) || (_role == ammWrapperAddr()) || (_role == rfqAddr()) || (_role == rfqv2Addr()) || (_role == limitOrderAddr()),
                                          "PermanentStorage: not a valid role"
                                      );
                                  }
                                  permission[_storageId][_role] = _enabled;
                                  emit SetPermission(_storageId, _role, _enabled);
                              }
                              /************************************************************
                               *              Constructor and init functions               *
                               *************************************************************/
                              /// @dev Replacing constructor and initialize the contract. This function should only be called once.
                              function initialize(address _operator) external {
                                  require(keccak256(abi.encodePacked(version)) == keccak256(abi.encodePacked("")), "PermanentStorage: not upgrading from empty");
                                  require(_operator != address(0), "PermanentStorage: operator can not be zero address");
                                  operator = _operator;
                                  // Upgrade version
                                  version = "5.4.0";
                              }
                              /************************************************************
                               *                     Getter functions                      *
                               *************************************************************/
                              function hasPermission(bytes32 _storageId, address _role) external view override returns (bool) {
                                  return permission[_storageId][_role];
                              }
                              function ammWrapperAddr() public view override returns (address) {
                                  return PSStorage.getStorage().ammWrapperAddr;
                              }
                              function pmmAddr() public view override returns (address) {
                                  return PSStorage.getStorage().pmmAddr;
                              }
                              function rfqAddr() public view override returns (address) {
                                  return PSStorage.getStorage().rfqAddr;
                              }
                              function rfqv2Addr() public view override returns (address) {
                                  return PSStorage.getStorage().rfqv2Addr;
                              }
                              function limitOrderAddr() public view override returns (address) {
                                  return PSStorage.getStorage().limitOrderAddr;
                              }
                              function wethAddr() external view override returns (address) {
                                  return PSStorage.getStorage().wethAddr;
                              }
                              function getCurvePoolInfo(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr
                              )
                                  external
                                  view
                                  override
                                  returns (
                                      int128 takerAssetIndex,
                                      int128 makerAssetIndex,
                                      uint16 swapMethod,
                                      bool supportGetDx
                                  )
                              {
                                  // underlying_coins
                                  int128 i = AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][_takerAssetAddr];
                                  int128 j = AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][_makerAssetAddr];
                                  supportGetDx = AMMWrapperStorage.getStorage().curveSupportGetDx[_makerAddr];
                                  swapMethod = 0;
                                  if (i != 0 && j != 0) {
                                      // in underlying_coins list
                                      takerAssetIndex = i;
                                      makerAssetIndex = j;
                                      // exchange_underlying
                                      swapMethod = 2;
                                  } else {
                                      // in coins list
                                      int128 iWrapped = AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][_takerAssetAddr];
                                      int128 jWrapped = AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][_makerAssetAddr];
                                      if (iWrapped != 0 && jWrapped != 0) {
                                          takerAssetIndex = iWrapped;
                                          makerAssetIndex = jWrapped;
                                          // exchange
                                          swapMethod = 1;
                                      } else {
                                          revert("PermanentStorage: invalid pair");
                                      }
                                  }
                                  return (takerAssetIndex, makerAssetIndex, swapMethod, supportGetDx);
                              }
                              function isAMMTransactionSeen(bytes32 _transactionHash) external view override returns (bool) {
                                  return AMMWrapperStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isRFQTransactionSeen(bytes32 _transactionHash) external view override returns (bool) {
                                  return RFQStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isRFQOfferFilled(bytes32 _offerHash) external view override returns (bool) {
                                  return RFQv2Storage.getStorage().filledOffer[_offerHash];
                              }
                              function isLimitOrderTransactionSeen(bytes32 _transactionHash) external view override returns (bool) {
                                  return LimitOrderStorage.getStorage().transactionSeen[_transactionHash];
                              }
                              function isLimitOrderAllowFillSeen(bytes32 _allowFillHash) external view override returns (bool) {
                                  return LimitOrderStorage.getStorage().allowFillSeen[_allowFillHash];
                              }
                              function isRelayerValid(address _relayer) external view override returns (bool) {
                                  return AMMWrapperStorage.getStorage().relayerValid[_relayer];
                              }
                              /************************************************************
                               *           Management functions for Operator               *
                               *************************************************************/
                              /// @dev Update AMMWrapper contract address.
                              function upgradeAMMWrapper(address _newAMMWrapper) external onlyOperator {
                                  PSStorage.getStorage().ammWrapperAddr = _newAMMWrapper;
                                  emit UpgradeAMMWrapper(_newAMMWrapper);
                              }
                              /// @dev Update PMM contract address.
                              function upgradePMM(address _newPMM) external onlyOperator {
                                  PSStorage.getStorage().pmmAddr = _newPMM;
                                  emit UpgradePMM(_newPMM);
                              }
                              /// @dev Update RFQ contract address.
                              function upgradeRFQ(address _newRFQ) external onlyOperator {
                                  PSStorage.getStorage().rfqAddr = _newRFQ;
                                  emit UpgradeRFQ(_newRFQ);
                              }
                              /// @dev Update RFQv2 contract address.
                              function upgradeRFQv2(address _newRFQv2) external onlyOperator {
                                  PSStorage.getStorage().rfqv2Addr = _newRFQv2;
                                  emit UpgradeRFQv2(_newRFQv2);
                              }
                              /// @dev Update Limit Order contract address.
                              function upgradeLimitOrder(address _newLimitOrder) external onlyOperator {
                                  PSStorage.getStorage().limitOrderAddr = _newLimitOrder;
                                  emit UpgradeLimitOrder(_newLimitOrder);
                              }
                              /// @dev Update WETH contract address.
                              function upgradeWETH(address _newWETH) external onlyOperator {
                                  PSStorage.getStorage().wethAddr = _newWETH;
                                  emit UpgradeWETH(_newWETH);
                              }
                              /************************************************************
                               *                   External functions                      *
                               *************************************************************/
                              function setCurvePoolInfo(
                                  address _makerAddr,
                                  address[] calldata _underlyingCoins,
                                  address[] calldata _coins,
                                  bool _supportGetDx
                              ) external override isPermitted(curveTokenIndexStorageId, msg.sender) {
                                  int128 underlyingCoinsLength = int128(_underlyingCoins.length);
                                  for (int128 i = 0; i < underlyingCoinsLength; ++i) {
                                      address assetAddr = _underlyingCoins[uint256(i)];
                                      // underlying coins for original DAI, USDC, TUSD
                                      AMMWrapperStorage.getStorage().curveTokenIndexes[_makerAddr][assetAddr] = i + 1; // Start the index from 1
                                  }
                                  int128 coinsLength = int128(_coins.length);
                                  for (int128 i = 0; i < coinsLength; ++i) {
                                      address assetAddr = _coins[uint256(i)];
                                      // wrapped coins for cDAI, cUSDC, yDAI, yUSDC, yTUSD, yBUSD
                                      AMMWrapperStorage.getStorage().curveWrappedTokenIndexes[_makerAddr][assetAddr] = i + 1; // Start the index from 1
                                  }
                                  AMMWrapperStorage.getStorage().curveSupportGetDx[_makerAddr] = _supportGetDx;
                                  emit SetCurvePoolInfo(_makerAddr, _underlyingCoins, _coins, _supportGetDx);
                              }
                              function setAMMTransactionSeen(bytes32 _transactionHash) external override isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!AMMWrapperStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  AMMWrapperStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setRFQTransactionSeen(bytes32 _transactionHash) external override isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!RFQStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  RFQStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setRFQOfferFilled(bytes32 _offerHash) external override isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!RFQv2Storage.getStorage().filledOffer[_offerHash], "PermanentStorage: offer already filled");
                                  RFQv2Storage.getStorage().filledOffer[_offerHash] = true;
                              }
                              function setLimitOrderTransactionSeen(bytes32 _transactionHash) external override isPermitted(transactionSeenStorageId, msg.sender) {
                                  require(!LimitOrderStorage.getStorage().transactionSeen[_transactionHash], "PermanentStorage: transaction seen before");
                                  LimitOrderStorage.getStorage().transactionSeen[_transactionHash] = true;
                              }
                              function setLimitOrderAllowFillSeen(bytes32 _allowFillHash) external override isPermitted(allowFillSeenStorageId, msg.sender) {
                                  require(!LimitOrderStorage.getStorage().allowFillSeen[_allowFillHash], "PermanentStorage: allow fill seen before");
                                  LimitOrderStorage.getStorage().allowFillSeen[_allowFillHash] = true;
                              }
                              function setRelayersValid(address[] calldata _relayers, bool[] calldata _isValids) external override isPermitted(relayerValidStorageId, msg.sender) {
                                  require(_relayers.length == _isValids.length, "PermanentStorage: inputs length mismatch");
                                  for (uint256 i = 0; i < _relayers.length; ++i) {
                                      AMMWrapperStorage.getStorage().relayerValid[_relayers[i]] = _isValids[i];
                                      emit SetRelayerValid(_relayers[i], _isValids[i]);
                                  }
                              }
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity >=0.7.0;
                          interface IPermanentStorage {
                              // Operator events
                              event OperatorNominated(address indexed newOperator);
                              event OperatorChanged(address indexed oldOperator, address indexed newOperator);
                              event SetPermission(bytes32 storageId, address role, bool enabled);
                              event UpgradeAMMWrapper(address newAMMWrapper);
                              event UpgradePMM(address newPMM);
                              event UpgradeRFQ(address newRFQ);
                              event UpgradeRFQv2(address newRFQv2);
                              event UpgradeLimitOrder(address newLimitOrder);
                              event UpgradeWETH(address newWETH);
                              event SetCurvePoolInfo(address makerAddr, address[] underlyingCoins, address[] coins, bool supportGetD);
                              event SetRelayerValid(address relayer, bool valid);
                              function hasPermission(bytes32 _storageId, address _role) external view returns (bool);
                              function ammWrapperAddr() external view returns (address);
                              function pmmAddr() external view returns (address);
                              function rfqAddr() external view returns (address);
                              function rfqv2Addr() external view returns (address);
                              function limitOrderAddr() external view returns (address);
                              function wethAddr() external view returns (address);
                              function getCurvePoolInfo(
                                  address _makerAddr,
                                  address _takerAssetAddr,
                                  address _makerAssetAddr
                              )
                                  external
                                  view
                                  returns (
                                      int128 takerAssetIndex,
                                      int128 makerAssetIndex,
                                      uint16 swapMethod,
                                      bool supportGetDx
                                  );
                              function setCurvePoolInfo(
                                  address _makerAddr,
                                  address[] calldata _underlyingCoins,
                                  address[] calldata _coins,
                                  bool _supportGetDx
                              ) external;
                              function isAMMTransactionSeen(bytes32 _transactionHash) external view returns (bool);
                              function isRFQTransactionSeen(bytes32 _transactionHash) external view returns (bool);
                              function isRFQOfferFilled(bytes32 _offerHash) external view returns (bool);
                              function isLimitOrderTransactionSeen(bytes32 _transactionHash) external view returns (bool);
                              function isLimitOrderAllowFillSeen(bytes32 _allowFillHash) external view returns (bool);
                              function isRelayerValid(address _relayer) external view returns (bool);
                              function setAMMTransactionSeen(bytes32 _transactionHash) external;
                              function setRFQTransactionSeen(bytes32 _transactionHash) external;
                              function setRFQOfferFilled(bytes32 _offerHash) external;
                              function setLimitOrderTransactionSeen(bytes32 _transactionHash) external;
                              function setLimitOrderAllowFillSeen(bytes32 _allowFillHash) external;
                              function setRelayersValid(address[] memory _relayers, bool[] memory _isValids) external;
                          }
                          // SPDX-License-Identifier: MIT
                          pragma solidity ^0.7.6;
                          library PSStorage {
                              bytes32 private constant STORAGE_SLOT = 0x92dd52b981a2dd69af37d8a3febca29ed6a974aede38ae66e4ef773173aba471;
                              struct Storage {
                                  address ammWrapperAddr;
                                  address pmmAddr;
                                  address wethAddr;
                                  address rfqAddr;
                                  address limitOrderAddr;
                                  address rfqv2Addr;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.storage.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library AMMWrapperStorage {
                              bytes32 private constant STORAGE_SLOT = 0xd38d862c9fa97c2fa857a46e08022d272a3579c114ca4f335f1e5fcb692c045e;
                              struct Storage {
                                  mapping(bytes32 => bool) transactionSeen;
                                  // curve pool => underlying token address => underlying token index
                                  mapping(address => mapping(address => int128)) curveTokenIndexes;
                                  mapping(address => bool) relayerValid;
                                  // 5.1.0 appended storage
                                  // curve pool => wrapped token address => wrapped token index
                                  mapping(address => mapping(address => int128)) curveWrappedTokenIndexes;
                                  mapping(address => bool) curveSupportGetDx;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.ammwrapper.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library RFQStorage {
                              bytes32 private constant STORAGE_SLOT = 0x9174e76494cfb023ddc1eb0effb6c12e107165382bbd0ecfddbc38ea108bbe52;
                              struct Storage {
                                  mapping(bytes32 => bool) transactionSeen;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.rfq.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library RFQv2Storage {
                              bytes32 private constant STORAGE_SLOT = 0x080acc42eac0383f7fcd5637f944d2e6a75ec0034a43cf5966b3e1fbe75ceddf;
                              struct Storage {
                                  mapping(bytes32 => bool) filledOffer;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.rfqv2.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          library LimitOrderStorage {
                              bytes32 private constant STORAGE_SLOT = 0xb1b5d1092eed9d9f9f6bdd5bf9fe04f7537770f37e1d84ac8960cc3acb80615c;
                              struct Storage {
                                  mapping(bytes32 => bool) transactionSeen;
                                  mapping(bytes32 => bool) allowFillSeen;
                              }
                              /// @dev Get the storage bucket for this contract.
                              function getStorage() internal pure returns (Storage storage stor) {
                                  assert(STORAGE_SLOT == bytes32(uint256(keccak256("permanent.limitorder.storage")) - 1));
                                  bytes32 slot = STORAGE_SLOT;
                                  // Dip into assembly to change the slot pointed to by the local
                                  // variable `stor`.
                                  // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
                                  assembly {
                                      stor.slot := slot
                                  }
                              }
                          }
                          

                          File 12 of 13: Spender
                          // SPDX-License-Identifier: MIT
                          // File: @openzeppelin/contracts/math/SafeMath.sol
                          
                          
                          pragma solidity ^0.6.0;
                          
                          /**
                           * @dev Wrappers over Solidity's arithmetic operations with added overflow
                           * checks.
                           *
                           * Arithmetic operations in Solidity wrap on overflow. This can easily result
                           * in bugs, because programmers usually assume that an overflow raises an
                           * error, which is the standard behavior in high level programming languages.
                           * `SafeMath` restores this intuition by reverting the transaction when an
                           * operation overflows.
                           *
                           * Using this library instead of the unchecked operations eliminates an entire
                           * class of bugs, so it's recommended to use it always.
                           */
                          library SafeMath {
                              /**
                               * @dev Returns the addition of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `+` operator.
                               *
                               * Requirements:
                               *
                               * - Addition cannot overflow.
                               */
                              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                                  uint256 c = a + b;
                                  require(c >= a, "SafeMath: addition overflow");
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting on
                               * overflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               *
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return sub(a, b, "SafeMath: subtraction overflow");
                              }
                          
                              /**
                               * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                               * overflow (when the result is negative).
                               *
                               * Counterpart to Solidity's `-` operator.
                               *
                               * Requirements:
                               *
                               * - Subtraction cannot overflow.
                               */
                              function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b <= a, errorMessage);
                                  uint256 c = a - b;
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the multiplication of two unsigned integers, reverting on
                               * overflow.
                               *
                               * Counterpart to Solidity's `*` operator.
                               *
                               * Requirements:
                               *
                               * - Multiplication cannot overflow.
                               */
                              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                                  // benefit is lost if 'b' is also tested.
                                  // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                                  if (a == 0) {
                                      return 0;
                                  }
                          
                                  uint256 c = a * b;
                                  require(c / a == b, "SafeMath: multiplication overflow");
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the integer division of two unsigned integers. Reverts on
                               * division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return div(a, b, "SafeMath: division by zero");
                              }
                          
                              /**
                               * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
                               * division by zero. The result is rounded towards zero.
                               *
                               * Counterpart to Solidity's `/` operator. Note: this function uses a
                               * `revert` opcode (which leaves remaining gas untouched) while Solidity
                               * uses an invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b > 0, errorMessage);
                                  uint256 c = a / b;
                                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                          
                                  return c;
                              }
                          
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * Reverts when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                                  return mod(a, b, "SafeMath: modulo by zero");
                              }
                          
                              /**
                               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                               * Reverts with custom message when dividing by zero.
                               *
                               * Counterpart to Solidity's `%` operator. This function uses a `revert`
                               * opcode (which leaves remaining gas untouched) while Solidity uses an
                               * invalid opcode to revert (consuming all remaining gas).
                               *
                               * Requirements:
                               *
                               * - The divisor cannot be zero.
                               */
                              function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                                  require(b != 0, errorMessage);
                                  return a % b;
                              }
                          }
                          
                          // File: @openzeppelin/contracts/token/ERC20/IERC20.sol
                          
                          
                          pragma solidity ^0.6.0;
                          
                          /**
                           * @dev Interface of the ERC20 standard as defined in the EIP.
                           */
                          interface IERC20 {
                              /**
                               * @dev Returns the amount of tokens in existence.
                               */
                              function totalSupply() external view returns (uint256);
                          
                              /**
                               * @dev Returns the amount of tokens owned by `account`.
                               */
                              function balanceOf(address account) external view returns (uint256);
                          
                              /**
                               * @dev Moves `amount` tokens from the caller's account to `recipient`.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transfer(address recipient, uint256 amount) external returns (bool);
                          
                              /**
                               * @dev Returns the remaining number of tokens that `spender` will be
                               * allowed to spend on behalf of `owner` through {transferFrom}. This is
                               * zero by default.
                               *
                               * This value changes when {approve} or {transferFrom} are called.
                               */
                              function allowance(address owner, address spender) external view returns (uint256);
                          
                              /**
                               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * IMPORTANT: Beware that changing an allowance with this method brings the risk
                               * that someone may use both the old and the new allowance by unfortunate
                               * transaction ordering. One possible solution to mitigate this race
                               * condition is to first reduce the spender's allowance to 0 and set the
                               * desired value afterwards:
                               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                               *
                               * Emits an {Approval} event.
                               */
                              function approve(address spender, uint256 amount) external returns (bool);
                          
                              /**
                               * @dev Moves `amount` tokens from `sender` to `recipient` using the
                               * allowance mechanism. `amount` is then deducted from the caller's
                               * allowance.
                               *
                               * Returns a boolean value indicating whether the operation succeeded.
                               *
                               * Emits a {Transfer} event.
                               */
                              function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                          
                              /**
                               * @dev Emitted when `value` tokens are moved from one account (`from`) to
                               * another (`to`).
                               *
                               * Note that `value` may be zero.
                               */
                              event Transfer(address indexed from, address indexed to, uint256 value);
                          
                              /**
                               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                               * a call to {approve}. `value` is the new allowance.
                               */
                              event Approval(address indexed owner, address indexed spender, uint256 value);
                          }
                          
                          // File: contracts/interface/IAllowanceTarget.sol
                          
                          pragma solidity ^0.6.0;
                          
                          interface IAllowanceTarget {
                              function setSpenderWithTimelock(address _newSpender) external;
                              function completeSetSpender() external;
                              function executeCall(address payable _target, bytes calldata _callData) external returns (bytes memory resultData);
                              function teardown() external;
                          }
                          
                          // File: contracts/Spender.sol
                          
                          
                          pragma solidity ^0.6.5;
                          
                          
                          
                          
                          /**
                           * @dev Spender contract
                           */
                          contract Spender {
                              using SafeMath for uint256;
                          
                              // Constants do not have storage slot.
                              address private constant ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
                              address private constant ZERO_ADDRESS = address(0);
                              uint256 constant private TIME_LOCK_DURATION = 1 days;
                          
                              // Below are the variables which consume storage slots.
                              address public operator;
                              address public allowanceTarget;
                              mapping(address => bool) private authorized;
                              mapping(address => bool) private tokenBlacklist;
                              uint256 public numPendingAuthorized;
                              mapping(uint256 => address) public pendingAuthorized;
                              uint256 public timelockExpirationTime;
                              uint256 public contractDeployedTime;
                              bool public timelockActivated;
                          
                          
                          
                              /************************************************************
                              *          Access control and ownership management          *
                              *************************************************************/
                              modifier onlyOperator() {
                                  require(operator == msg.sender, "Spender: not the operator");
                                  _;
                              }
                          
                              modifier onlyAuthorized() {
                                  require(authorized[msg.sender], "Spender: not authorized");
                                  _;
                              }
                          
                              function transferOwnership(address _newOperator) external onlyOperator {
                                  require(_newOperator != address(0), "Spender: operator can not be zero address");
                                  operator = _newOperator;
                              }
                          
                          
                              /************************************************************
                              *                    Timelock management                    *
                              *************************************************************/
                              /// @dev Everyone can activate timelock after the contract has been deployed for more than 1 day.
                              function activateTimelock() external {
                                  bool canActivate = block.timestamp.sub(contractDeployedTime) > 1 days;
                                  require(canActivate && ! timelockActivated, "Spender: can not activate timelock yet or has been activated");
                                  timelockActivated = true;
                              }
                          
                          
                              /************************************************************
                              *              Constructor and init functions               *
                              *************************************************************/
                              constructor(address _operator) public {
                                  require(_operator != address(0), "Spender: _operator should not be 0");
                          
                                  // Set operator
                                  operator = _operator;
                                  timelockActivated = false;
                                  contractDeployedTime = block.timestamp;
                              }
                          
                              function setAllowanceTarget(address _allowanceTarget) external onlyOperator {
                                  require(allowanceTarget == address(0), "Spender: can not reset allowance target");
                          
                                  // Set allowanceTarget
                                  allowanceTarget = _allowanceTarget;
                              }
                          
                          
                          
                              /************************************************************
                              *          AllowanceTarget interaction functions            *
                              *************************************************************/
                              function setNewSpender(address _newSpender) external onlyOperator {
                                  IAllowanceTarget(allowanceTarget).setSpenderWithTimelock(_newSpender);
                              }
                          
                              function teardownAllowanceTarget() external onlyOperator {
                                  IAllowanceTarget(allowanceTarget).teardown();
                              }
                          
                          
                          
                              /************************************************************
                              *           Whitelist and blacklist functions               *
                              *************************************************************/
                              function isBlacklisted(address _tokenAddr) external view returns (bool) {
                                  return tokenBlacklist[_tokenAddr];
                              }
                          
                              function blacklist(address[] calldata _tokenAddrs, bool[] calldata _isBlacklisted) external onlyOperator {
                                  require(_tokenAddrs.length == _isBlacklisted.length, "Spender: length mismatch");
                                  for (uint256 i = 0; i < _tokenAddrs.length; i++) {
                                      tokenBlacklist[_tokenAddrs[i]] = _isBlacklisted[i];
                                  }
                              }
                              
                              function isAuthorized(address _caller) external view returns (bool) {
                                  return authorized[_caller];
                              }
                          
                              function authorize(address[] calldata _pendingAuthorized) external onlyOperator {
                                  require(_pendingAuthorized.length > 0, "Spender: authorize list is empty");
                                  require(numPendingAuthorized == 0 && timelockExpirationTime == 0, "Spender: an authorize current in progress");
                          
                                  if (timelockActivated) {
                                      numPendingAuthorized = _pendingAuthorized.length;
                                      for (uint256 i = 0; i < _pendingAuthorized.length; i++) {
                                          require(_pendingAuthorized[i] != address(0), "Spender: can not authorize zero address");
                                          pendingAuthorized[i] = _pendingAuthorized[i];
                                      }
                                      timelockExpirationTime = now + TIME_LOCK_DURATION;
                                  } else {
                                      for (uint256 i = 0; i < _pendingAuthorized.length; i++) {
                                          require(_pendingAuthorized[i] != address(0), "Spender: can not authorize zero address");
                                          authorized[_pendingAuthorized[i]] = true;
                                      }
                                  }
                              }
                          
                              function completeAuthorize() external {
                                  require(timelockExpirationTime != 0, "Spender: no pending authorize");
                                  require(now >= timelockExpirationTime, "Spender: time lock not expired yet");
                          
                                  for (uint256 i = 0; i < numPendingAuthorized; i++) {
                                      authorized[pendingAuthorized[i]] = true;
                                      delete pendingAuthorized[i];
                                  }
                                  timelockExpirationTime = 0;
                                  numPendingAuthorized = 0;
                              }
                          
                              function deauthorize(address[] calldata _deauthorized) external onlyOperator {
                                  for (uint256 i = 0; i < _deauthorized.length; i++) {
                                      authorized[_deauthorized[i]] = false;
                                  }
                              }
                          
                          
                              /************************************************************
                              *                   External functions                      *
                              *************************************************************/
                              /// @dev Spend tokens on user's behalf. Only an authority can call this.
                              /// @param _user The user to spend token from.
                              /// @param _tokenAddr The address of the token.
                              /// @param _amount Amount to spend.
                              function spendFromUser(address _user, address _tokenAddr, uint256 _amount) external onlyAuthorized {
                                  require(! tokenBlacklist[_tokenAddr], "Spender: token is blacklisted");
                          
                                  if (_tokenAddr != ETH_ADDRESS && _tokenAddr != ZERO_ADDRESS) {
                          
                                      uint256 balanceBefore = IERC20(_tokenAddr).balanceOf(msg.sender);
                                      (bool callSucceed, ) = address(allowanceTarget).call(
                                          abi.encodeWithSelector(
                                              IAllowanceTarget.executeCall.selector,
                                              _tokenAddr,
                                              abi.encodeWithSelector(
                                                  IERC20.transferFrom.selector,
                                                  _user,
                                                  msg.sender,
                                                  _amount
                                              )
                                          )
                                      );
                                      require(callSucceed, "Spender: ERC20 transferFrom failed");
                                      // Check balance
                                      uint256 balanceAfter = IERC20(_tokenAddr).balanceOf(msg.sender);
                                      require(balanceAfter.sub(balanceBefore) == _amount, "Spender: ERC20 transferFrom result mismatch");
                          
                                  }
                              }
                          }

                          File 13 of 13: AllowanceTarget
                          // SPDX-License-Identifier: MIT
                          // File: @openzeppelin/contracts/utils/Address.sol
                          
                          
                          pragma solidity ^0.6.2;
                          
                          /**
                           * @dev Collection of functions related to the address type
                           */
                          library Address {
                              /**
                               * @dev Returns true if `account` is a contract.
                               *
                               * [IMPORTANT]
                               * ====
                               * It is unsafe to assume that an address for which this function returns
                               * false is an externally-owned account (EOA) and not a contract.
                               *
                               * Among others, `isContract` will return false for the following
                               * types of addresses:
                               *
                               *  - an externally-owned account
                               *  - a contract in construction
                               *  - an address where a contract will be created
                               *  - an address where a contract lived, but was destroyed
                               * ====
                               */
                              function isContract(address account) internal view returns (bool) {
                                  // This method relies in extcodesize, which returns 0 for contracts in
                                  // construction, since the code is only stored at the end of the
                                  // constructor execution.
                          
                                  uint256 size;
                                  // solhint-disable-next-line no-inline-assembly
                                  assembly { size := extcodesize(account) }
                                  return size > 0;
                              }
                          
                              /**
                               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                               * `recipient`, forwarding all available gas and reverting on errors.
                               *
                               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                               * of certain opcodes, possibly making contracts go over the 2300 gas limit
                               * imposed by `transfer`, making them unable to receive funds via
                               * `transfer`. {sendValue} removes this limitation.
                               *
                               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                               *
                               * IMPORTANT: because control is transferred to `recipient`, care must be
                               * taken to not create reentrancy vulnerabilities. Consider using
                               * {ReentrancyGuard} or the
                               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                               */
                              function sendValue(address payable recipient, uint256 amount) internal {
                                  require(address(this).balance >= amount, "Address: insufficient balance");
                          
                                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                  (bool success, ) = recipient.call{ value: amount }("");
                                  require(success, "Address: unable to send value, recipient may have reverted");
                              }
                          
                              /**
                               * @dev Performs a Solidity function call using a low level `call`. A
                               * plain`call` is an unsafe replacement for a function call: use this
                               * function instead.
                               *
                               * If `target` reverts with a revert reason, it is bubbled up by this
                               * function (like regular Solidity function calls).
                               *
                               * Returns the raw returned data. To convert to the expected return value,
                               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                               *
                               * Requirements:
                               *
                               * - `target` must be a contract.
                               * - calling `target` with `data` must not revert.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                return functionCall(target, data, "Address: low-level call failed");
                              }
                          
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                               * `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                  return _functionCallWithValue(target, data, 0, errorMessage);
                              }
                          
                              /**
                               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                               * but also transferring `value` wei to `target`.
                               *
                               * Requirements:
                               *
                               * - the calling contract must have an ETH balance of at least `value`.
                               * - the called Solidity function must be `payable`.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                              }
                          
                              /**
                               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                               * with `errorMessage` as a fallback revert reason when `target` reverts.
                               *
                               * _Available since v3.1._
                               */
                              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                  require(address(this).balance >= value, "Address: insufficient balance for call");
                                  return _functionCallWithValue(target, data, value, errorMessage);
                              }
                          
                              function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
                                  require(isContract(target), "Address: call to non-contract");
                          
                                  // solhint-disable-next-line avoid-low-level-calls
                                  (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
                                  if (success) {
                                      return returndata;
                                  } else {
                                      // Look for revert reason and bubble it up if present
                                      if (returndata.length > 0) {
                                          // The easiest way to bubble the revert reason is using memory via assembly
                          
                                          // solhint-disable-next-line no-inline-assembly
                                          assembly {
                                              let returndata_size := mload(returndata)
                                              revert(add(32, returndata), returndata_size)
                                          }
                                      } else {
                                          revert(errorMessage);
                                      }
                                  }
                              }
                          }
                          
                          // File: contracts/interface/IAllowanceTarget.sol
                          
                          pragma solidity ^0.6.0;
                          
                          interface IAllowanceTarget {
                              function setSpenderWithTimelock(address _newSpender) external;
                              function completeSetSpender() external;
                              function executeCall(address payable _target, bytes calldata _callData) external returns (bytes memory resultData);
                              function teardown() external;
                          }
                          
                          // File: contracts/AllowanceTarget.sol
                          
                          
                          pragma solidity ^0.6.5;
                          
                          
                          
                          /**
                           * @dev AllowanceTarget contract
                           */
                          contract AllowanceTarget is IAllowanceTarget {
                              using Address for address;
                          
                              uint256 constant private TIME_LOCK_DURATION = 1 days;
                          
                              address public spender;
                              address public newSpender;
                              uint256 public timelockExpirationTime;
                          
                              modifier onlySpender() {
                                  require(spender == msg.sender, "AllowanceTarget: not the spender");
                                  _;
                              }
                          
                          
                              constructor(address _spender) public {
                                  require(_spender != address(0), "AllowanceTarget: _spender should not be 0");
                          
                                  // Set spender
                                  spender = _spender;
                              }
                          
                          
                              function setSpenderWithTimelock(address _newSpender) override external onlySpender {
                                  require(_newSpender.isContract(), "AllowanceTarget: new spender not a contract");
                                  require(newSpender == address(0) && timelockExpirationTime == 0, "AllowanceTarget: SetSpender in progress");
                          
                                  timelockExpirationTime = now + TIME_LOCK_DURATION;
                                  newSpender = _newSpender;
                              }
                          
                              function completeSetSpender() override external {
                                  require(timelockExpirationTime != 0, "AllowanceTarget: no pending SetSpender");
                                  require(now >= timelockExpirationTime, "AllowanceTarget: time lock not expired yet");
                          
                                  // Set new spender
                                  spender = newSpender;
                                  // Reset
                                  timelockExpirationTime = 0;
                                  newSpender = address(0);
                              }
                          
                          
                              function teardown() override external onlySpender {
                                  selfdestruct(payable(spender));
                              }
                          
                          
                              /// @dev Execute an arbitrary call. Only an authority can call this.
                              /// @param target The call target.
                              /// @param callData The call data.
                              /// @return resultData The data returned by the call.
                              function executeCall(
                                  address payable target,
                                  bytes calldata callData
                              )
                                  override
                                  external
                                  onlySpender
                                  returns (bytes memory resultData)
                              {
                                  bool success;
                                  (success, resultData) = target.call(callData);
                                  if (!success) {
                                      // Get the error message returned
                                      assembly {
                                          let ptr := mload(0x40)
                                          let size := returndatasize()
                                          returndatacopy(ptr, 0, size)
                                          revert(ptr, size)
                                      }
                                  }
                              }
                          }