ETH Price: $2,427.40 (-3.21%)

Transaction Decoder

Block:
21389152 at Dec-12-2024 09:35:47 PM +UTC
Transaction Fee:
0.005973745603459296 ETH $14.50
Gas Used:
317,861 Gas / 18.793578336 Gwei

Emitted Events:

311 UniswapV2Pair.Transfer( from=[Sender] 0xb3fa4378318dff382dfc49622bbd45fa2e87671b, to=[Receiver] AdminUpgradeabilityProxy, value=3016620625799671216251 )
312 AdminUpgradeabilityProxy.0xeb65d0f36862bbd8763c5e2c983c9d753267d223eee35a224d8d0a9d7ef433a2( 0xeb65d0f36862bbd8763c5e2c983c9d753267d223eee35a224d8d0a9d7ef433a2, 0x0000000000000000000000001cac2a71e16d3a6bec2dfcf4fe89f338058b439d, 0x000000000000000000000000b3fa4378318dff382dfc49622bbd45fa2e87671b, 0000000000000000000000000000000000000000000000000000000000005bb0, 0000000000000000000000000000000000000000000000a388055c6c79f8787b, 00000000000000000000000000000000000000000000000000000000693f2cf2 )

Account State Difference:

  Address   Before After State Difference Code
0x1cAC2A71...8058B439D
0x725363e7...858d90b87 0.079215309810556726 Eth0.117876470944709826 Eth0.0386611611341531
(beaverbuild)
14.449573625293821649 Eth14.449624088126468616 Eth0.000050462832646967
0xb3FA4378...A2e87671b
0.099254668346387357 Eth
Nonce: 4
0.054619761608774961 Eth
Nonce: 5
0.044634906737612396
0xE2fE530C...37f1435fB
(TrustSwap: Team Finance Lock )

Execution Trace

ETH 0.0386611611341531 AdminUpgradeabilityProxy.5af06fed( )
  • ETH 0.0386611611341531 LockToken.lockToken( _tokenAddress=0x1cAC2A71e16D3A6bEc2dfcF4fE89f338058B439D, _withdrawalAddress=0xb3FA4378318dFF382Dfc49622BBD45fA2e87671b, _amount=3016620625799671216251, _unlockTime=1765747954, _mintNFT=False, referrer=0x0000000000000000000000000000000000000000 ) => ( _id=23472 )
    • TransparentUpgradeableProxy.STATICCALL( )
      • PriceEstimator.DELEGATECALL( )
      • TransparentUpgradeableProxy.4b08d235( )
        • PriceEstimator.getFeeInETHWithOracle( _feesInUSD=150000000 ) => ( 38661161134153100 )
          • EACAggregatorProxy.STATICCALL( )
            • AccessControlledOCR2Aggregator.STATICCALL( )
            • ETH 0.0386611611341531 0x725363e764ea25233f29a14594f6388858d90b87.CALL( )
            • UniswapV2Pair.balanceOf( 0xE2fE530C047f2d85298b07D9333C05737f1435fB ) => ( 0 )
            • UniswapV2Pair.transferFrom( from=0xb3FA4378318dFF382Dfc49622BBD45fA2e87671b, to=0xE2fE530C047f2d85298b07D9333C05737f1435fB, value=3016620625799671216251 ) => ( True )
            • UniswapV2Pair.balanceOf( 0xE2fE530C047f2d85298b07D9333C05737f1435fB ) => ( 3016620625799671216251 )
              lockToken[LockToken (ln:128)]
              File 1 of 7: AdminUpgradeabilityProxy
              // File: @openzeppelin/upgrades/contracts/upgradeability/Proxy.sol
              
              pragma solidity ^0.5.0;
              
              /**
               * @title Proxy
               * @dev Implements delegation of calls to other contracts, with proper
               * forwarding of return values and bubbling of failures.
               * It defines a fallback function that delegates all calls to the address
               * returned by the abstract _implementation() internal function.
               */
              contract Proxy {
                /**
                 * @dev Fallback function.
                 * Implemented entirely in `_fallback`.
                 */
                function () payable external {
                  _fallback();
                }
              
                /**
                 * @return The Address of the implementation.
                 */
                function _implementation() internal view returns (address);
              
                /**
                 * @dev Delegates execution to an implementation contract.
                 * This is a low level function that doesn't return to its internal call site.
                 * It will return to the external caller whatever the implementation returns.
                 * @param implementation Address to delegate.
                 */
                function _delegate(address implementation) internal {
                  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 Function that is run as the first thing in the fallback function.
                 * Can be redefined in derived contracts to add functionality.
                 * Redefinitions must call super._willFallback().
                 */
                function _willFallback() internal {
                }
              
                /**
                 * @dev fallback implementation.
                 * Extracted to enable manual triggering.
                 */
                function _fallback() internal {
                  _willFallback();
                  _delegate(_implementation());
                }
              }
              
              // File: @openzeppelin/upgrades/contracts/utils/Address.sol
              
              pragma solidity ^0.5.0;
              
              /**
               * Utility library of inline functions on addresses
               *
               * Source https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-solidity/v2.1.3/contracts/utils/Address.sol
               * This contract is copied here and renamed from the original to avoid clashes in the compiled artifacts
               * when the user imports a zos-lib contract (that transitively causes this contract to be compiled and added to the
               * build/artifacts folder) as well as the vanilla Address implementation from an openzeppelin version.
               */
              library OpenZeppelinUpgradesAddress {
                  /**
                   * Returns whether the target address is a contract
                   * @dev This function will return false if invoked during the constructor of a contract,
                   * as the code is not actually created until after the constructor finishes.
                   * @param account address of the account to check
                   * @return whether the target address is a contract
                   */
                  function isContract(address account) internal view returns (bool) {
                      uint256 size;
                      // XXX Currently there is no better way to check if there is a contract in an address
                      // than to check the size of the code at that address.
                      // See https://ethereum.stackexchange.com/a/14016/36603
                      // for more details about how this works.
                      // TODO Check this again before the Serenity release, because all addresses will be
                      // contracts then.
                      // solhint-disable-next-line no-inline-assembly
                      assembly { size := extcodesize(account) }
                      return size > 0;
                  }
              }
              
              // File: @openzeppelin/upgrades/contracts/upgradeability/BaseUpgradeabilityProxy.sol
              
              pragma solidity ^0.5.0;
              
              
              
              /**
               * @title BaseUpgradeabilityProxy
               * @dev This contract implements a proxy that allows to change the
               * implementation address to which it will delegate.
               * Such a change is called an implementation upgrade.
               */
              contract BaseUpgradeabilityProxy is Proxy {
                /**
                 * @dev Emitted when the implementation is upgraded.
                 * @param implementation Address of the new implementation.
                 */
                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 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
              
                /**
                 * @dev Returns the current implementation.
                 * @return Address of the current implementation
                 */
                function _implementation() internal view returns (address impl) {
                  bytes32 slot = IMPLEMENTATION_SLOT;
                  assembly {
                    impl := sload(slot)
                  }
                }
              
                /**
                 * @dev Upgrades the proxy to a new implementation.
                 * @param newImplementation Address of the new implementation.
                 */
                function _upgradeTo(address newImplementation) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
                }
              
                /**
                 * @dev Sets the implementation address of the proxy.
                 * @param newImplementation Address of the new implementation.
                 */
                function _setImplementation(address newImplementation) internal {
                  require(OpenZeppelinUpgradesAddress.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
              
                  bytes32 slot = IMPLEMENTATION_SLOT;
              
                  assembly {
                    sstore(slot, newImplementation)
                  }
                }
              }
              
              // File: @openzeppelin/upgrades/contracts/upgradeability/UpgradeabilityProxy.sol
              
              pragma solidity ^0.5.0;
              
              
              /**
               * @title UpgradeabilityProxy
               * @dev Extends BaseUpgradeabilityProxy with a constructor for initializing
               * implementation and init data.
               */
              contract UpgradeabilityProxy is BaseUpgradeabilityProxy {
                /**
                 * @dev Contract constructor.
                 * @param _logic Address of the initial implementation.
                 * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
                 * It should include the signature and the parameters of the function to be called, as described in
                 * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
                 * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
                 */
                constructor(address _logic, bytes memory _data) public payable {
                  assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
                  _setImplementation(_logic);
                  if(_data.length > 0) {
                    (bool success,) = _logic.delegatecall(_data);
                    require(success);
                  }
                }  
              }
              
              // File: @openzeppelin/upgrades/contracts/upgradeability/BaseAdminUpgradeabilityProxy.sol
              
              pragma solidity ^0.5.0;
              
              
              /**
               * @title BaseAdminUpgradeabilityProxy
               * @dev This contract combines an upgradeability proxy with an authorization
               * mechanism for administrative tasks.
               * All external functions in this contract must be guarded by the
               * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
               * feature proposal that would enable this to be done automatically.
               */
              contract BaseAdminUpgradeabilityProxy is BaseUpgradeabilityProxy {
                /**
                 * @dev Emitted when the administration has been transferred.
                 * @param previousAdmin Address of the previous admin.
                 * @param newAdmin Address of the new admin.
                 */
                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 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
              
                /**
                 * @dev Modifier to check whether the `msg.sender` is the admin.
                 * If it is, it will run the function. Otherwise, it will delegate the call
                 * to the implementation.
                 */
                modifier ifAdmin() {
                  if (msg.sender == _admin()) {
                    _;
                  } else {
                    _fallback();
                  }
                }
              
                /**
                 * @return The address of the proxy admin.
                 */
                function admin() external ifAdmin returns (address) {
                  return _admin();
                }
              
                /**
                 * @return The address of the implementation.
                 */
                function implementation() external ifAdmin returns (address) {
                  return _implementation();
                }
              
                /**
                 * @dev Changes the admin of the proxy.
                 * Only the current admin can call this function.
                 * @param newAdmin Address to transfer proxy administration to.
                 */
                function changeAdmin(address newAdmin) external ifAdmin {
                  require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
                  emit AdminChanged(_admin(), newAdmin);
                  _setAdmin(newAdmin);
                }
              
                /**
                 * @dev Upgrade the backing implementation of the proxy.
                 * Only the admin can call this function.
                 * @param newImplementation Address of the new implementation.
                 */
                function upgradeTo(address newImplementation) external ifAdmin {
                  _upgradeTo(newImplementation);
                }
              
                /**
                 * @dev Upgrade the backing implementation of the proxy and call a function
                 * on the new implementation.
                 * This is useful to initialize the proxied contract.
                 * @param newImplementation Address of the new implementation.
                 * @param data Data to send as msg.data in the low level call.
                 * It should include the signature and the parameters of the function to be called, as described in
                 * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
                 */
                function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
                  _upgradeTo(newImplementation);
                  (bool success,) = newImplementation.delegatecall(data);
                  require(success);
                }
              
                /**
                 * @return The admin slot.
                 */
                function _admin() internal view returns (address adm) {
                  bytes32 slot = ADMIN_SLOT;
                  assembly {
                    adm := sload(slot)
                  }
                }
              
                /**
                 * @dev Sets the address of the proxy admin.
                 * @param newAdmin Address of the new proxy admin.
                 */
                function _setAdmin(address newAdmin) internal {
                  bytes32 slot = ADMIN_SLOT;
              
                  assembly {
                    sstore(slot, newAdmin)
                  }
                }
              
                /**
                 * @dev Only fall back when the sender is not the admin.
                 */
                function _willFallback() internal {
                  require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
                  super._willFallback();
                }
              }
              
              // File: @openzeppelin/upgrades/contracts/upgradeability/AdminUpgradeabilityProxy.sol
              
              pragma solidity ^0.5.0;
              
              
              /**
               * @title AdminUpgradeabilityProxy
               * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for 
               * initializing the implementation, admin, and init data.
               */
              contract AdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, UpgradeabilityProxy {
                /**
                 * Contract constructor.
                 * @param _logic address of the initial implementation.
                 * @param _admin Address of the proxy administrator.
                 * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
                 * It should include the signature and the parameters of the function to be called, as described in
                 * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
                 * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
                 */
                constructor(address _logic, address _admin, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable {
                  assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
                  _setAdmin(_admin);
                }
              }

              File 2 of 7: UniswapV2Pair
              // File: contracts/interfaces/IUniswapV2Pair.sol
              
              pragma solidity >=0.5.0;
              
              interface IUniswapV2Pair {
                  event Approval(address indexed owner, address indexed spender, uint value);
                  event Transfer(address indexed from, address indexed to, uint value);
              
                  function name() external pure returns (string memory);
                  function symbol() external pure returns (string memory);
                  function decimals() external pure returns (uint8);
                  function totalSupply() external view returns (uint);
                  function balanceOf(address owner) external view returns (uint);
                  function allowance(address owner, address spender) external view returns (uint);
              
                  function approve(address spender, uint value) external returns (bool);
                  function transfer(address to, uint value) external returns (bool);
                  function transferFrom(address from, address to, uint value) external returns (bool);
              
                  function DOMAIN_SEPARATOR() external view returns (bytes32);
                  function PERMIT_TYPEHASH() external pure returns (bytes32);
                  function nonces(address owner) external view returns (uint);
              
                  function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
              
                  event Mint(address indexed sender, uint amount0, uint amount1);
                  event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
                  event Swap(
                      address indexed sender,
                      uint amount0In,
                      uint amount1In,
                      uint amount0Out,
                      uint amount1Out,
                      address indexed to
                  );
                  event Sync(uint112 reserve0, uint112 reserve1);
              
                  function MINIMUM_LIQUIDITY() external pure returns (uint);
                  function factory() external view returns (address);
                  function token0() external view returns (address);
                  function token1() external view returns (address);
                  function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
                  function price0CumulativeLast() external view returns (uint);
                  function price1CumulativeLast() external view returns (uint);
                  function kLast() external view returns (uint);
              
                  function mint(address to) external returns (uint liquidity);
                  function burn(address to) external returns (uint amount0, uint amount1);
                  function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
                  function skim(address to) external;
                  function sync() external;
              
                  function initialize(address, address) external;
              }
              
              // File: contracts/interfaces/IUniswapV2ERC20.sol
              
              pragma solidity >=0.5.0;
              
              interface IUniswapV2ERC20 {
                  event Approval(address indexed owner, address indexed spender, uint value);
                  event Transfer(address indexed from, address indexed to, uint value);
              
                  function name() external pure returns (string memory);
                  function symbol() external pure returns (string memory);
                  function decimals() external pure returns (uint8);
                  function totalSupply() external view returns (uint);
                  function balanceOf(address owner) external view returns (uint);
                  function allowance(address owner, address spender) external view returns (uint);
              
                  function approve(address spender, uint value) external returns (bool);
                  function transfer(address to, uint value) external returns (bool);
                  function transferFrom(address from, address to, uint value) external returns (bool);
              
                  function DOMAIN_SEPARATOR() external view returns (bytes32);
                  function PERMIT_TYPEHASH() external pure returns (bytes32);
                  function nonces(address owner) external view returns (uint);
              
                  function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
              }
              
              // File: contracts/libraries/SafeMath.sol
              
              pragma solidity =0.5.16;
              
              // a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)
              
              library SafeMath {
                  function add(uint x, uint y) internal pure returns (uint z) {
                      require((z = x + y) >= x, 'ds-math-add-overflow');
                  }
              
                  function sub(uint x, uint y) internal pure returns (uint z) {
                      require((z = x - y) <= x, 'ds-math-sub-underflow');
                  }
              
                  function mul(uint x, uint y) internal pure returns (uint z) {
                      require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
                  }
              }
              
              // File: contracts/UniswapV2ERC20.sol
              
              pragma solidity =0.5.16;
              
              
              
              contract UniswapV2ERC20 is IUniswapV2ERC20 {
                  using SafeMath for uint;
              
                  string public constant name = 'Uniswap V2';
                  string public constant symbol = 'UNI-V2';
                  uint8 public constant decimals = 18;
                  uint  public totalSupply;
                  mapping(address => uint) public balanceOf;
                  mapping(address => mapping(address => uint)) public allowance;
              
                  bytes32 public DOMAIN_SEPARATOR;
                  // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
                  bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
                  mapping(address => uint) public nonces;
              
                  event Approval(address indexed owner, address indexed spender, uint value);
                  event Transfer(address indexed from, address indexed to, uint value);
              
                  constructor() public {
                      uint chainId;
                      assembly {
                          chainId := chainid
                      }
                      DOMAIN_SEPARATOR = keccak256(
                          abi.encode(
                              keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                              keccak256(bytes(name)),
                              keccak256(bytes('1')),
                              chainId,
                              address(this)
                          )
                      );
                  }
              
                  function _mint(address to, uint value) internal {
                      totalSupply = totalSupply.add(value);
                      balanceOf[to] = balanceOf[to].add(value);
                      emit Transfer(address(0), to, value);
                  }
              
                  function _burn(address from, uint value) internal {
                      balanceOf[from] = balanceOf[from].sub(value);
                      totalSupply = totalSupply.sub(value);
                      emit Transfer(from, address(0), value);
                  }
              
                  function _approve(address owner, address spender, uint value) private {
                      allowance[owner][spender] = value;
                      emit Approval(owner, spender, value);
                  }
              
                  function _transfer(address from, address to, uint value) private {
                      balanceOf[from] = balanceOf[from].sub(value);
                      balanceOf[to] = balanceOf[to].add(value);
                      emit Transfer(from, to, value);
                  }
              
                  function approve(address spender, uint value) external returns (bool) {
                      _approve(msg.sender, spender, value);
                      return true;
                  }
              
                  function transfer(address to, uint value) external returns (bool) {
                      _transfer(msg.sender, to, value);
                      return true;
                  }
              
                  function transferFrom(address from, address to, uint value) external returns (bool) {
                      if (allowance[from][msg.sender] != uint(-1)) {
                          allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
                      }
                      _transfer(from, to, value);
                      return true;
                  }
              
                  function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
                      require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
                      bytes32 digest = keccak256(
                          abi.encodePacked(
                              '\x19\x01',
                              DOMAIN_SEPARATOR,
                              keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
                          )
                      );
                      address recoveredAddress = ecrecover(digest, v, r, s);
                      require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
                      _approve(owner, spender, value);
                  }
              }
              
              // File: contracts/libraries/Math.sol
              
              pragma solidity =0.5.16;
              
              // a library for performing various math operations
              
              library Math {
                  function min(uint x, uint y) internal pure returns (uint z) {
                      z = x < y ? x : y;
                  }
              
                  // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
                  function sqrt(uint y) internal pure returns (uint z) {
                      if (y > 3) {
                          z = y;
                          uint x = y / 2 + 1;
                          while (x < z) {
                              z = x;
                              x = (y / x + x) / 2;
                          }
                      } else if (y != 0) {
                          z = 1;
                      }
                  }
              }
              
              // File: contracts/libraries/UQ112x112.sol
              
              pragma solidity =0.5.16;
              
              // a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))
              
              // range: [0, 2**112 - 1]
              // resolution: 1 / 2**112
              
              library UQ112x112 {
                  uint224 constant Q112 = 2**112;
              
                  // encode a uint112 as a UQ112x112
                  function encode(uint112 y) internal pure returns (uint224 z) {
                      z = uint224(y) * Q112; // never overflows
                  }
              
                  // divide a UQ112x112 by a uint112, returning a UQ112x112
                  function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
                      z = x / uint224(y);
                  }
              }
              
              // File: contracts/interfaces/IERC20.sol
              
              pragma solidity >=0.5.0;
              
              interface IERC20 {
                  event Approval(address indexed owner, address indexed spender, uint value);
                  event Transfer(address indexed from, address indexed to, uint value);
              
                  function name() external view returns (string memory);
                  function symbol() external view returns (string memory);
                  function decimals() external view returns (uint8);
                  function totalSupply() external view returns (uint);
                  function balanceOf(address owner) external view returns (uint);
                  function allowance(address owner, address spender) external view returns (uint);
              
                  function approve(address spender, uint value) external returns (bool);
                  function transfer(address to, uint value) external returns (bool);
                  function transferFrom(address from, address to, uint value) external returns (bool);
              }
              
              // File: contracts/interfaces/IUniswapV2Factory.sol
              
              pragma solidity >=0.5.0;
              
              interface IUniswapV2Factory {
                  event PairCreated(address indexed token0, address indexed token1, address pair, uint);
              
                  function feeTo() external view returns (address);
                  function feeToSetter() external view returns (address);
              
                  function getPair(address tokenA, address tokenB) external view returns (address pair);
                  function allPairs(uint) external view returns (address pair);
                  function allPairsLength() external view returns (uint);
              
                  function createPair(address tokenA, address tokenB) external returns (address pair);
              
                  function setFeeTo(address) external;
                  function setFeeToSetter(address) external;
              }
              
              // File: contracts/interfaces/IUniswapV2Callee.sol
              
              pragma solidity >=0.5.0;
              
              interface IUniswapV2Callee {
                  function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
              }
              
              // File: contracts/UniswapV2Pair.sol
              
              pragma solidity =0.5.16;
              
              
              
              
              
              
              
              
              contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
                  using SafeMath  for uint;
                  using UQ112x112 for uint224;
              
                  uint public constant MINIMUM_LIQUIDITY = 10**3;
                  bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));
              
                  address public factory;
                  address public token0;
                  address public token1;
              
                  uint112 private reserve0;           // uses single storage slot, accessible via getReserves
                  uint112 private reserve1;           // uses single storage slot, accessible via getReserves
                  uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves
              
                  uint public price0CumulativeLast;
                  uint public price1CumulativeLast;
                  uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event
              
                  uint private unlocked = 1;
                  modifier lock() {
                      require(unlocked == 1, 'UniswapV2: LOCKED');
                      unlocked = 0;
                      _;
                      unlocked = 1;
                  }
              
                  function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
                      _reserve0 = reserve0;
                      _reserve1 = reserve1;
                      _blockTimestampLast = blockTimestampLast;
                  }
              
                  function _safeTransfer(address token, address to, uint value) private {
                      (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
                      require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
                  }
              
                  event Mint(address indexed sender, uint amount0, uint amount1);
                  event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
                  event Swap(
                      address indexed sender,
                      uint amount0In,
                      uint amount1In,
                      uint amount0Out,
                      uint amount1Out,
                      address indexed to
                  );
                  event Sync(uint112 reserve0, uint112 reserve1);
              
                  constructor() public {
                      factory = msg.sender;
                  }
              
                  // called once by the factory at time of deployment
                  function initialize(address _token0, address _token1) external {
                      require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
                      token0 = _token0;
                      token1 = _token1;
                  }
              
                  // update reserves and, on the first call per block, price accumulators
                  function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
                      require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
                      uint32 blockTimestamp = uint32(block.timestamp % 2**32);
                      uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
                      if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
                          // * never overflows, and + overflow is desired
                          price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
                          price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
                      }
                      reserve0 = uint112(balance0);
                      reserve1 = uint112(balance1);
                      blockTimestampLast = blockTimestamp;
                      emit Sync(reserve0, reserve1);
                  }
              
                  // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
                  function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
                      address feeTo = IUniswapV2Factory(factory).feeTo();
                      feeOn = feeTo != address(0);
                      uint _kLast = kLast; // gas savings
                      if (feeOn) {
                          if (_kLast != 0) {
                              uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                              uint rootKLast = Math.sqrt(_kLast);
                              if (rootK > rootKLast) {
                                  uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                                  uint denominator = rootK.mul(5).add(rootKLast);
                                  uint liquidity = numerator / denominator;
                                  if (liquidity > 0) _mint(feeTo, liquidity);
                              }
                          }
                      } else if (_kLast != 0) {
                          kLast = 0;
                      }
                  }
              
                  // this low-level function should be called from a contract which performs important safety checks
                  function mint(address to) external lock returns (uint liquidity) {
                      (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
                      uint balance0 = IERC20(token0).balanceOf(address(this));
                      uint balance1 = IERC20(token1).balanceOf(address(this));
                      uint amount0 = balance0.sub(_reserve0);
                      uint amount1 = balance1.sub(_reserve1);
              
                      bool feeOn = _mintFee(_reserve0, _reserve1);
                      uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
                      if (_totalSupply == 0) {
                          liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
                         _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
                      } else {
                          liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
                      }
                      require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
                      _mint(to, liquidity);
              
                      _update(balance0, balance1, _reserve0, _reserve1);
                      if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
                      emit Mint(msg.sender, amount0, amount1);
                  }
              
                  // this low-level function should be called from a contract which performs important safety checks
                  function burn(address to) external lock returns (uint amount0, uint amount1) {
                      (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
                      address _token0 = token0;                                // gas savings
                      address _token1 = token1;                                // gas savings
                      uint balance0 = IERC20(_token0).balanceOf(address(this));
                      uint balance1 = IERC20(_token1).balanceOf(address(this));
                      uint liquidity = balanceOf[address(this)];
              
                      bool feeOn = _mintFee(_reserve0, _reserve1);
                      uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
                      amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
                      amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
                      require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
                      _burn(address(this), liquidity);
                      _safeTransfer(_token0, to, amount0);
                      _safeTransfer(_token1, to, amount1);
                      balance0 = IERC20(_token0).balanceOf(address(this));
                      balance1 = IERC20(_token1).balanceOf(address(this));
              
                      _update(balance0, balance1, _reserve0, _reserve1);
                      if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
                      emit Burn(msg.sender, amount0, amount1, to);
                  }
              
                  // this low-level function should be called from a contract which performs important safety checks
                  function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
                      require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
                      (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
                      require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');
              
                      uint balance0;
                      uint balance1;
                      { // scope for _token{0,1}, avoids stack too deep errors
                      address _token0 = token0;
                      address _token1 = token1;
                      require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
                      if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
                      if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
                      if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
                      balance0 = IERC20(_token0).balanceOf(address(this));
                      balance1 = IERC20(_token1).balanceOf(address(this));
                      }
                      uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
                      uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
                      require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
                      { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
                      uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
                      uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
                      require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
                      }
              
                      _update(balance0, balance1, _reserve0, _reserve1);
                      emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
                  }
              
                  // force balances to match reserves
                  function skim(address to) external lock {
                      address _token0 = token0; // gas savings
                      address _token1 = token1; // gas savings
                      _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
                      _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
                  }
              
                  // force reserves to match balances
                  function sync() external lock {
                      _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
                  }
              }

              File 3 of 7: LockToken
              //Team Token Locking Contract
              pragma solidity 0.6.2;
              pragma experimental ABIEncoderV2;
              import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC20/SafeERC20.sol";
              import "@openzeppelin/contracts-ethereum-package/contracts/access/Ownable.sol";
              import "@openzeppelin/contracts-ethereum-package/contracts/utils/Pausable.sol";
              import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC721/IERC721Receiver.sol";
              import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC721/IERC721Enumerable.sol";
              import "./interfaces/IERC20Extended.sol";
              import "./interfaces/IPriceEstimator.sol";
              import "./interfaces/IV3Migrator.sol";
              import "./interfaces/IERC721Extended.sol";
              import "./interfaces/IUniswapV3PositionManager.sol";
              contract LockToken is Initializable, OwnableUpgradeSafe, PausableUpgradeSafe, IERC721Receiver{
                  using SafeERC20 for IERC20;
                  using SafeMath for uint256;
                  using Address for address;
                  /*
                   * deposit vars
                  */
                  struct Items {
                      address tokenAddress;
                      address withdrawalAddress;
                      uint256 tokenAmount;
                      uint256 unlockTime;
                      bool withdrawn;
                  }
                  struct NFTItems {
                      address tokenAddress;
                      address withdrawalAddress;
                      uint256 tokenAmount;
                      uint256 unlockTime;
                      bool withdrawn;
                      uint256 tokenId;
                  }
                  uint256 public depositId;
                  uint256[] public allDepositIds;
                  mapping(address => uint256[]) public depositsByWithdrawalAddress;
                  mapping(uint256 => Items) public lockedToken;
                  mapping(address => mapping(address => uint256)) public walletTokenBalance;
                  /*
                   * Fee vars
                  */
                  address public usdTokenAddress;
                  IPriceEstimator public priceEstimator;
                  //feeInUSD is in Wei, i.e 25USD = 25000000 USDT
                  uint256 public feesInUSD;
                  address payable public companyWallet;
                  //list of free tokens
                  mapping(address => bool) private listFreeTokens;
                  mapping (uint256 => NFTItems) public lockedNFTs;
                  
                  //migrating liquidity
                  IERC721Enumerable public nonfungiblePositionManager;
                  IV3Migrator public v3Migrator;
                  //new deposit id to old deposit id
                  mapping(uint256 => uint256) public listMigratedDepositIds;
                  //NFT Liquidity
                  mapping(uint256 => bool) public nftMinted;
                  address public NFT;
                  bool private _notEntered;
                  uint256 private constant MAX_PERCENTAGE = 10000;
                  uint256 public referralDiscount;
                  uint256 public referrerCut;
                  // mapping of whitelisted wallet addresses
                  mapping(address => bool) public whitelistedWallets;
                  // mapping of admins that can whitelist
                  mapping (address => bool) public whitelistAdmins;
                  event LogTokenWithdrawal(uint256 id, address indexed tokenAddress, address indexed withdrawalAddress, uint256 amount);
                  event LogNFTWithdrawal(uint256 id, address indexed tokenAddress, uint256 tokenId, address indexed withdrawalAddress, uint256 amount);
                  event FeesChanged(uint256 indexed fees);
                  event ReferralParamsChanged(uint256 referralDiscount, uint256 referrerCut);
                  event ReferrerRewarded(address indexed addr, uint256 referrerCut);
                  // event LiquidityMigrated(address indexed migrator, uint256 oldDepositId, uint256 newDepositId, uint256 v3TokenId);
                  // event EthReceived(address, uint256);
                  event Deposit(uint256 id, address indexed tokenAddress, address indexed withdrawalAddress, uint256 amount, uint256 unlockTime);
                  event DepositNFT(uint256 id, address indexed tokenAddress, uint256 tokenId, address indexed withdrawalAddress, uint256 amount, uint256 unlockTime);
                  event LockDurationExtended(uint256 id, uint256 unlockTime);
                  event LockSplit(uint256 id, uint256 remainingAmount, uint256 splitLockId, uint256 newSplitLockAmount);
                  event CompanyWalletUpdated(address companyWallet);
                  event NftContractUpdated(address nftContract);
                  event FreeTokenListUpdated(address token, bool isFree);
                  event WhiteListUpdated(address wallet, bool noFee);
                  event WhiteListAdminUpdated(address wallet, bool status);
                  modifier nonReentrant() {
                      // On the first call to nonReentrant, _notEntered will be true
                      require(_notEntered, "ReentrancyGuard: reentrant call");
                      // Any calls to nonReentrant after this point will fail
                      _notEntered = false;
                      _;
                      // By storing the original value once again, a refund is triggered (see
                      // https://eips.ethereum.org/EIPS/eip-2200)
                      _notEntered = true;
                  }
                  modifier onlyContract(address account)
                  {
                      require(account.isContract(), "The address does not contain a contract");
                      _;
                  }
                  /**
                  * @dev initialize
                  */
                  function initialize()
                  external
                  {
                      __LockToken_init();
                  }
                  function __LockToken_init()
                  internal
                  initializer
                  {
                      __Context_init_unchained();
                      __Ownable_init_unchained();
                      __Pausable_init_unchained();
                      _notEntered = true;
                  }
                  function onERC721Received(
                      address,
                      address,
                      uint256,
                      bytes memory
                  ) public virtual override returns (bytes4) {
                      return this.onERC721Received.selector;
                  }
                  /**
                   *lock tokens
                  */
                  function lockToken(
                      address _tokenAddress,
                      address _withdrawalAddress,
                      uint256 _amount,
                      uint256 _unlockTime,
                      bool _mintNFT,
                      address referrer
                  )
                  external 
                  payable
                  whenNotPaused
                  nonReentrant
                  returns (uint256 _id)
                  {
                      require(_amount > 0, "Amount is zero");
                      require(_unlockTime > block.timestamp, "Invalid unlock time");
                      uint256 amountIn = _amount;
                      referrer == address(0) ? _chargeFees(_tokenAddress) : _chargeFeesReferral(_tokenAddress, referrer);
                          
                      uint256 balanceBefore = IERC20(_tokenAddress).balanceOf(address(this));
                      // transfer tokens into contract
                      IERC20(_tokenAddress).safeTransferFrom(_msgSender(), address(this), _amount);
                      amountIn = IERC20(_tokenAddress).balanceOf(address(this)).sub(balanceBefore);
                      //update balance in address
                      walletTokenBalance[_tokenAddress][_withdrawalAddress] = walletTokenBalance[_tokenAddress][_withdrawalAddress].add(amountIn);
                      _id = _addERC20Deposit(_tokenAddress, _withdrawalAddress, amountIn, _unlockTime);
                      if(_mintNFT) {
                          _mintNFTforLock(_id, _withdrawalAddress);
                      }
                      emit Deposit(_id, _tokenAddress, _withdrawalAddress, amountIn, _unlockTime);
                  }
                  /**
                   *lock nft
                  */
                  function lockNFT(
                      address _tokenAddress,
                      address _withdrawalAddress,
                      uint256 _amount,
                      uint256 _unlockTime,
                      uint256 _tokenId,
                      bool _mintNFT,
                      address referrer
                  )
                  external 
                  payable
                  whenNotPaused
                  nonReentrant
                  returns (uint256 _id)
                  {
                      require(_amount == 1, "Invalid amount");
                      require(_unlockTime > block.timestamp, "Invalid unlock time");
                      referrer == address(0) ? _chargeFees(_tokenAddress) : _chargeFeesReferral(_tokenAddress, referrer);
                      //update balance in address
                      walletTokenBalance[_tokenAddress][_withdrawalAddress] = walletTokenBalance[_tokenAddress][_withdrawalAddress].add(_amount);
                      _id = ++depositId;
                      lockedNFTs[_id] = NFTItems({
                          tokenAddress: _tokenAddress, 
                          withdrawalAddress: _withdrawalAddress,
                          tokenAmount: _amount,
                          unlockTime: _unlockTime,
                          withdrawn: false,
                          tokenId: _tokenId
                      });
                      allDepositIds.push(_id);
                      depositsByWithdrawalAddress[_withdrawalAddress].push(_id);
                      if(_mintNFT) {
                          _mintNFTforLock(_id, _withdrawalAddress);
                      }
                      IERC721(_tokenAddress).safeTransferFrom(_msgSender(), address(this), _tokenId);
                      emit DepositNFT(_id, _tokenAddress, _tokenId, _withdrawalAddress, _amount, _unlockTime);
                  }
                  /**
                   *Extend lock Duration
                  */
                  function extendLockDuration(
                      uint256 _id,
                      uint256 _unlockTime
                  )
                  external nonReentrant
                  {
                      require(_unlockTime > block.timestamp, "Invalid unlock time");
                      NFTItems storage lockedNFT = lockedNFTs[_id];
                      Items storage lockedERC20 = lockedToken[_id];
                      if(nftMinted[_id]) {
                          require(IERC721Extended(NFT).ownerOf(_id) == _msgSender(), "Unauthorised to extend");
                      } else {
                          require((_msgSender() == lockedNFT.withdrawalAddress || 
                              _msgSender() == lockedERC20.withdrawalAddress),
                              "Unauthorised to extend"
                          );
                      }
                      if(lockedNFT.tokenAddress != address(0x0))
                      {
                          require(_unlockTime > lockedNFT.unlockTime, "NFT: smaller unlockTime than existing");
                          require(!lockedNFT.withdrawn, "NFT: already withdrawn");
                          //set new unlock time
                          lockedNFT.unlockTime = _unlockTime;
                      }
                      else
                      {
                          require(
                              _unlockTime > lockedERC20.unlockTime,
                              "ERC20: smaller unlockTime than existing"
                          );
                          require(
                              !lockedERC20.withdrawn,
                              "ERC20: already withdrawn"
                          );
                          //set new unlock time
                          lockedERC20.unlockTime = _unlockTime;
                      }
                      emit LockDurationExtended(_id, _unlockTime);
                  }
                  /**
                   *transfer locked tokens
                  */
                  function transferLocks(
                      uint256 _id,
                      address _receiverAddress
                  )
                  external nonReentrant
                  {
                      address msg_sender;
                      NFTItems storage lockedNFT = lockedNFTs[_id];
                      Items storage lockedERC20 = lockedToken[_id];
                      if( lockedNFT.tokenAddress != address(0x0) )
                      {
                          if (_msgSender() == NFT && nftMinted[_id])
                          {
                              msg_sender = lockedNFT.withdrawalAddress;
                          }
                          else
                          {
                              require((!nftMinted[_id]), "NFT: Transfer Lock NFT");
                              require(_msgSender() == lockedNFT.withdrawalAddress, "Unauthorised to transfer");
                              msg_sender = _msgSender();
                          }
                          require(!lockedNFT.withdrawn, "NFT: already withdrawn");
                          require(msg_sender != _receiverAddress, "Cannot transfer to self");
                          //decrease sender's token balance
                          walletTokenBalance[lockedNFT.tokenAddress][msg_sender] = 
                              walletTokenBalance[lockedNFT.tokenAddress][msg_sender].sub(lockedNFT.tokenAmount);
                          
                          //increase receiver's token balance
                          walletTokenBalance[lockedNFT.tokenAddress][_receiverAddress] = 
                              walletTokenBalance[lockedNFT.tokenAddress][_receiverAddress].add(lockedNFT.tokenAmount);
                          
                          _removeDepositsForWithdrawalAddress(_id, msg_sender);
                          
                          //Assign this id to receiver address
                          lockedNFT.withdrawalAddress = _receiverAddress;
                      }
                      else
                      {
                          if (_msgSender() == NFT && nftMinted[_id])
                          {
                              msg_sender = lockedERC20.withdrawalAddress;
                          }
                          else {
                              require((!nftMinted[_id]), "ERC20: Transfer Lock NFT");
                              require(_msgSender() == lockedERC20.withdrawalAddress, "Unauthorised to transfer");
                              msg_sender = _msgSender();
                          }
                          
                          require(!lockedERC20.withdrawn, "ERC20: already withdrawn");
                          require(msg_sender != _receiverAddress, "Cannot transfer to self");
                          //decrease sender's token balance
                          walletTokenBalance[lockedERC20.tokenAddress][msg_sender] = 
                          walletTokenBalance[lockedERC20.tokenAddress][msg_sender].sub(lockedERC20.tokenAmount);
                          
                          //increase receiver's token balance
                          walletTokenBalance[lockedERC20.tokenAddress][_receiverAddress] = 
                          walletTokenBalance[lockedERC20.tokenAddress][_receiverAddress].add(lockedERC20.tokenAmount);
                          
                          _removeDepositsForWithdrawalAddress(_id, msg_sender);
                          
                          //Assign this id to receiver address
                          lockedERC20.withdrawalAddress = _receiverAddress;
                      }
                      
                      depositsByWithdrawalAddress[_receiverAddress].push(_id);
                  }
                  /**
                   *withdraw tokens
                  */
                  function withdrawTokens(
                      uint256 _id,
                      uint256 _amount
                  )
                  external
                  nonReentrant
                  {
                      if(nftMinted[_id]) {
                          require(IERC721Extended(NFT).ownerOf(_id) == _msgSender(), "Unauthorised to unlock");
                      }
                      NFTItems memory lockedNFT = lockedNFTs[_id];
                      Items storage lockedERC20 = lockedToken[_id];
                      require(
                          (_msgSender() == lockedNFT.withdrawalAddress || _msgSender() == lockedERC20.withdrawalAddress),
                          "Unauthorised to unlock"
                      );
                      //amount is ignored for erc-721 locks, in the future if 1155 locks are supported, we need to cater to amount var
                      if(lockedNFT.tokenAddress != address(0x0)) {
                          require(block.timestamp >= lockedNFT.unlockTime, "Unlock time not reached");
                          require(!lockedNFT.withdrawn, "NFT: already withdrawn");
                          _removeNFTDeposit(_id);
                          if(nftMinted[_id])
                          {
                              nftMinted[_id] = false;
                              IERC721Extended(NFT).burn(_id);
                          }
                          // transfer tokens to wallet address
                          IERC721(lockedNFT.tokenAddress).safeTransferFrom(address(this), _msgSender(), lockedNFT.tokenId);
                          emit LogNFTWithdrawal(_id, lockedNFT.tokenAddress, lockedNFT.tokenId, _msgSender(), lockedNFT.tokenAmount);
                      }
                      else
                      {
                          require(block.timestamp >= lockedERC20.unlockTime, "Unlock time not reached");
                          require(!lockedERC20.withdrawn, "ERC20: already withdrawn");
                          require(_amount > 0, "ERC20: Cannot Withdraw 0 Tokens");
                          require(lockedERC20.tokenAmount >= _amount, "Insufficent Balance to withdraw");
                          //full withdrawl
                          if(lockedERC20.tokenAmount == _amount){
                              _removeERC20Deposit(_id);
                              if (nftMinted[_id]){
                                  nftMinted[_id] = false;
                                  IERC721Extended(NFT).burn(_id);
                              }
                          }
                          else {
                              //partial withdrawl
                              lockedERC20.tokenAmount = lockedERC20.tokenAmount.sub(_amount);
                              walletTokenBalance[lockedERC20.tokenAddress][lockedERC20.withdrawalAddress] = 
                                  walletTokenBalance[lockedERC20.tokenAddress][lockedERC20.withdrawalAddress].sub(_amount);
                          }
                          // transfer tokens to wallet address
                          IERC20(lockedERC20.tokenAddress).safeTransfer(_msgSender(), _amount);
                          emit LogTokenWithdrawal(_id, lockedERC20.tokenAddress, _msgSender(), _amount);
                      }
                  }
                  /**
                  Split existing ERC20 Lock into 2
                  @dev This function will split a single lock into two induviual locks
                  @param _id represents the lockId of the token lock you are to split
                  @param _splitAmount is the amount of tokens in wei that will be 
                  shifted from the old lock to the new split lock
                  @param _splitUnlockTime the unlock time for the newly created split lock
                  must always be >= to unlockTime of lock it is being split from
                  @param _mintNFT is a boolean check on weather the new split lock will have an NFT minted
                   */
                   
                  function splitLock(
                      uint256 _id, 
                      uint256 _splitAmount,
                      uint256 _splitUnlockTime,
                      bool _mintNFT
                  ) 
                  external 
                  payable
                  whenNotPaused
                  nonReentrant
                  returns (uint256 _splitLockId)
                  {
                      require(_splitAmount > 0, "Amount is zero");
                      Items storage lockedERC20 = lockedToken[_id];
                      // NFTItems memory lockedNFT = lockedNFTs[_id];
                      address lockedNFTAddress = lockedNFTs[_id].tokenAddress;
                      //Check to ensure an NFT lock is not being split
                      require(lockedNFTAddress == address(0x0), "Can't split locked NFT");
                      uint256 lockedERC20Amount = lockedToken[_id].tokenAmount;
                      address lockedERC20Address = lockedToken[_id].tokenAddress;
                      address lockedERC20WithdrawlAddress = lockedToken[_id].withdrawalAddress;
                      require(lockedERC20Address != address(0x0), "Can't split empty lock");
                      if(nftMinted[_id]){
                          require(
                              IERC721(NFT).ownerOf(_id) == _msgSender(),
                              "Unauthorised to Split"
                          );
                      }
                      require(
                          _msgSender() == lockedERC20WithdrawlAddress,
                           "Unauthorised to Split"
                      );
                      require(!lockedERC20.withdrawn, "Cannot split withdrawn lock");
                      //Current locked tokenAmount must always be > _splitAmount as (lockedERC20.tokenAmount - _splitAmount) 
                      //will be the number of tokens retained in the original lock, while splitAmount will be the amount of tokens
                      //transferred to the new lock
                      require(lockedERC20Amount > _splitAmount, "Insufficient balance to split");
                      require(_splitUnlockTime >= lockedERC20.unlockTime, "Smaller unlock time than existing");
                      //charge Tier 2 fee for tokenSplit
                      _chargeFees(lockedERC20Address);
                      lockedERC20.tokenAmount = lockedERC20Amount.sub(_splitAmount);
                      //new token lock created with id stored in var _splitLockId
                      _splitLockId = _addERC20Deposit(lockedERC20Address, lockedERC20WithdrawlAddress, _splitAmount, _splitUnlockTime);
                      if(_mintNFT) {
                          _mintNFTforLock(_splitLockId, lockedERC20WithdrawlAddress);
                      }
                      emit LockSplit(_id, lockedERC20.tokenAmount, _splitLockId, _splitAmount);
                      emit Deposit(_splitLockId, lockedERC20Address, lockedERC20WithdrawlAddress, _splitAmount, _splitUnlockTime);
                  }
                  /**
                  * @dev Called by an admin to pause, triggers stopped state.
                  */
                  function pause()
                  external
                  onlyOwner 
                  {
                      _pause();
                  }
                  /**
                  * @dev Called by an admin to unpause, returns to normal state.
                  */
                  function unpause()
                  external
                  onlyOwner
                  {
                      _unpause();
                  }
                  function setFeeParams(address _priceEstimator, address _usdTokenAddress, uint256 _feesInUSD, address payable _companyWallet)
                  external
                  onlyOwner
                  onlyContract(_priceEstimator)
                  onlyContract(_usdTokenAddress)
                  {
                      require(_feesInUSD > 0, "fees should be greater than 0");
                      require(_companyWallet != address(0), "Invalid wallet address");
                      priceEstimator = IPriceEstimator(_priceEstimator);
                      usdTokenAddress = _usdTokenAddress;
                      feesInUSD = _feesInUSD;
                      companyWallet = _companyWallet;
                      emit FeesChanged(_feesInUSD);
                  }
                  function setFeesInUSD(uint256 _feesInUSD)
                  external
                  onlyOwner
                  {
                      require(_feesInUSD > 0,"fees should be greater than 0");
                      feesInUSD = _feesInUSD;
                      emit FeesChanged(_feesInUSD);
                  }
                  function setReferralParams(uint256 _referralDiscount, uint256 _referrerCut)
                  external
                  onlyOwner
                  {
                      require(_referralDiscount <= MAX_PERCENTAGE, "Referral discount invalid");
                      require(_referrerCut <= MAX_PERCENTAGE, "Referrer cut invalid");
                      referralDiscount = _referralDiscount;
                      referrerCut = _referrerCut;
                      emit ReferralParamsChanged(_referralDiscount, _referrerCut);
                  }
                  function setCompanyWallet(address payable _companyWallet)
                  external
                  onlyOwner
                  {
                      require(_companyWallet != address(0), "Invalid wallet address");
                      companyWallet = _companyWallet;
                      emit CompanyWalletUpdated(_companyWallet);
                  }
                  /**
                   * @dev Update the address of the NFT SC
                   * @param _nftContractAddress The address of the new NFT SC
                   */
                  function setNFTContract(address _nftContractAddress)
                  external
                  onlyOwner
                  onlyContract(_nftContractAddress)
                  {
                      NFT = _nftContractAddress;
                      emit NftContractUpdated(_nftContractAddress);
                  }
                  /**
                  * @dev called by admin to add given token to free tokens list
                  */
                  function addTokenToFreeList(address token)
                  external
                  onlyOwner
                  onlyContract(token)
                  {
                      listFreeTokens[token] = true;
                      emit FreeTokenListUpdated(token, true);
                  }
                  /**
                  * @dev called by admin to remove given token from free tokens list
                  */
                  function removeTokenFromFreeList(address token)
                  external
                  onlyOwner
                  onlyContract(token)
                  {
                      listFreeTokens[token] = false;
                      emit FreeTokenListUpdated(token, false);
                  }
                   /**
                  * @dev called by admin/owner to add add or remove wallet from whitelist
                  * @param wallet address to add/remove from whitelist
                  * @param noFee if to add or remove from whitelist
                  */
                  function updateWhitelist(address wallet, bool noFee)
                  external
                  {
                      require(
                          (whitelistAdmins[_msgSender()] || owner() == _msgSender()),
                          "Caller is not authorized to whitelist"
                      );
                      whitelistedWallets[wallet] = noFee;
                      emit WhiteListUpdated(wallet, noFee);
                  }
                  /*get total token balance in contract*/
                  function getTotalTokenBalance(address _tokenAddress) view external returns (uint256)
                  {
                     return IERC20(_tokenAddress).balanceOf(address(this));
                  }
                  
                  /*get allDepositIds*/
                  function getAllDepositIds() view external returns (uint256[] memory)
                  {
                      return allDepositIds;
                  }
                  
                  /*get getDepositDetails*/
                  function getDepositDetails(uint256 _id)
                  view
                  external
                  returns (
                      address _tokenAddress, 
                      address _withdrawalAddress, 
                      uint256 _tokenAmount, 
                      uint256 _unlockTime, 
                      bool _withdrawn, 
                      uint256 _tokenId,
                      bool _isNFT,
                      uint256 _migratedLockDepositId,
                      bool _isNFTMinted)
                  {
                      bool isNftMinted = nftMinted[_id];
                      NFTItems memory lockedNFT = lockedNFTs[_id];
                      Items memory lockedERC20 = lockedToken[_id];
                      if( lockedNFT.tokenAddress != address(0x0) )
                      {
                          // //old lock id
                          // uint256 migratedLockId = listMigratedDepositIds[_id];
                          return (
                              lockedNFT.tokenAddress,
                              lockedNFT.withdrawalAddress,
                              lockedNFT.tokenAmount,
                              lockedNFT.unlockTime,
                              lockedNFT.withdrawn, 
                              lockedNFT.tokenId,
                              true,
                              0,
                              isNftMinted
                          );
                      }
                      else
                      {
                          return (
                              lockedERC20.tokenAddress,
                              lockedERC20.withdrawalAddress,
                              lockedERC20.tokenAmount,
                              lockedERC20.unlockTime,
                              lockedERC20.withdrawn,
                              0,
                              false,
                              0,
                              isNftMinted
                          );
                      }
                  }
                  
                  /*get DepositsByWithdrawalAddress*/
                  function getDepositsByWithdrawalAddress(address _withdrawalAddress) view external returns (uint256[] memory)
                  {
                      return depositsByWithdrawalAddress[_withdrawalAddress];
                  }
                  
                  function getFeesInETH(address _tokenAddress)
                  public
                  view
                  returns (uint256)
                  {
                      //token listed free or fee params not set
                      if (whitelistedWallets[_msgSender()] || 
                          isFreeToken(_tokenAddress) ||
                          feesInUSD == 0 ||
                          address(priceEstimator) == address(0) ||
                          usdTokenAddress == address(0) 
                          )
                      {
                          return 0;
                      }
                      else 
                      {
                          if (priceEstimator.getUseOracle()) {
                              return priceEstimator.getFeeInETHWithOracle(feesInUSD);
                          }
                          //price should be estimated by 1 token because Uniswap algo changes price based on large amount
                          uint256 tokenBits = 10 ** uint256(IERC20Extended(usdTokenAddress).decimals());
                          uint256 estFeesInEthPerUnit = priceEstimator.getEstimatedETHforERC20(tokenBits, usdTokenAddress)[0];
                          //subtract uniswap 0.30% fees
                          //_uniswapFeePercentage is a percentage expressed in 1/10 (a tenth) of a percent hence we divide by 1000
                          estFeesInEthPerUnit = estFeesInEthPerUnit.sub(estFeesInEthPerUnit.mul(3).div(1000));
                          uint256 feesInEth = feesInUSD.mul(estFeesInEthPerUnit).div(tokenBits);
                          return feesInEth;
                      }
                  }
                  /**
                   * @dev Checks if token is in free list
                   * @param token The address to check
                  */
                  function isFreeToken(address token)
                  public
                  view
                  returns(bool)
                  {
                      return listFreeTokens[token];
                  }
                  function _addERC20Deposit (
                      address _tokenAddress,
                      address _withdrawalAddress,
                      uint256 amountIn,
                      uint256 _unlockTime
                  ) 
                  private 
                  returns (uint256 _id){
                      _id = ++depositId;
                      lockedToken[_id] = Items({
                          tokenAddress: _tokenAddress, 
                          withdrawalAddress: _withdrawalAddress,
                          tokenAmount: amountIn, 
                          unlockTime: _unlockTime, 
                          withdrawn: false
                      });
                      allDepositIds.push(_id);
                      depositsByWithdrawalAddress[_withdrawalAddress].push(_id);
                  }
                  function _removeERC20Deposit(
                      uint256 _id
                  )
                  private
                  {
                      Items storage lockedERC20 = lockedToken[_id];
                      //remove entry from lockedToken struct
                      lockedERC20.withdrawn = true;
                              
                      //update balance in address
                      walletTokenBalance[lockedERC20.tokenAddress][lockedERC20.withdrawalAddress] = 
                      walletTokenBalance[lockedERC20.tokenAddress][lockedERC20.withdrawalAddress].sub(lockedERC20.tokenAmount);
                      
                      _removeDepositsForWithdrawalAddress(_id, lockedERC20.withdrawalAddress);
                  }
                  function _removeNFTDeposit(
                      uint256 _id
                  )
                  private
                  {
                      NFTItems storage lockedNFT = lockedNFTs[_id];
                      //remove entry from lockedNFTs struct
                      lockedNFT.withdrawn = true;
                              
                      //update balance in address
                      walletTokenBalance[lockedNFT.tokenAddress][lockedNFT.withdrawalAddress] = 
                      walletTokenBalance[lockedNFT.tokenAddress][lockedNFT.withdrawalAddress].sub(lockedNFT.tokenAmount);
                      
                      _removeDepositsForWithdrawalAddress(_id, lockedNFTs[_id].withdrawalAddress);
                  }
                  function _removeDepositsForWithdrawalAddress(
                      uint256 _id,
                      address _withdrawalAddress
                  )
                  private
                  {
                      //remove this id from this address
                      uint256 j;
                      uint256 arrLength = depositsByWithdrawalAddress[_withdrawalAddress].length;
                      for (j=0; j<arrLength; j++) {
                          if (depositsByWithdrawalAddress[_withdrawalAddress][j] == _id) {
                              depositsByWithdrawalAddress[_withdrawalAddress][j] = 
                                  depositsByWithdrawalAddress[_withdrawalAddress][arrLength - 1];
                              depositsByWithdrawalAddress[_withdrawalAddress].pop();
                              break;
                          }
                      }
                  }
                  function _chargeFees(
                      address _tokenAddress
                  )
                  private
                  {
                      uint256 minRequiredFeeInEth = getFeesInETH(_tokenAddress);
                      if (minRequiredFeeInEth == 0) {
                          if (msg.value > 0) {
                              (bool refundSuccess,) = _msgSender().call.value(msg.value)("");
                              require(refundSuccess, "Refund failed.");
                          }
                          return;
                      }
                      bool feesBelowMinRequired = msg.value < minRequiredFeeInEth;
                      uint256 feeDiff = feesBelowMinRequired ? 
                          SafeMath.sub(minRequiredFeeInEth, msg.value) : 
                          SafeMath.sub(msg.value, minRequiredFeeInEth);
                          
                      if( feesBelowMinRequired ) {
                          // multiply by 10000 to convert to Basis Points (BPS)
                          uint256 feeSlippagePercentage = feeDiff.mul(10000).div(minRequiredFeeInEth);
                          //will allow if diff is less than 5% (500 BPS)
                          require(feeSlippagePercentage <= 500, "Fee Not Met");
                      }
                      (bool success,) = companyWallet.call.value(feesBelowMinRequired ? msg.value : minRequiredFeeInEth)("");
                      require(success, "Fee transfer failed");
                      /* refund difference. */
                      if (!feesBelowMinRequired && feeDiff > 0) {
                          (bool refundSuccess,) = _msgSender().call.value(feeDiff)("");
                          require(refundSuccess, "Refund failed");
                      }
                  }
                  /**
                   * @notice Collects fees from a Uniswap V3 position while maintaining the LP position
                   * @dev see https://github.com/Uniswap/v3-periphery/blob/main/contracts/NonfungiblePositionManager.sol#L309
                   * @param _id lockTokenId
                   */
                  function collectUniswapV3LPFees(
                      uint256 _id
                  ) 
                  external 
                  {
                      NFTItems storage lockedNFT = lockedNFTs[_id];
                      
                      //check if NFT actually exists
                      if(lockedNFT.tokenAddress != address(0x0)) {
                          //check if caller is the owner of locked NFT
                          require(
                              lockedNFT.withdrawalAddress == _msgSender(),
                              "Unauthorised to unlock"
                          );
                          //check if the NFT was already withdrawn
                          require(
                              !lockedNFT.withdrawn, 
                              "NFT: already withdrawn"
                          );
                      } else {
                          revert("No NFT locked");
                      }
                      uint128 maxAmount = uint128(-1); // type(uint128).max does not work with old compiler
                      IUniswapV3NonfungiblePositionManager.CollectParams memory collectFeeParams = 
                      IUniswapV3NonfungiblePositionManager.CollectParams({
                          tokenId: lockedNFT.tokenId,
                          recipient: lockedNFT.withdrawalAddress,
                          amount0Max: maxAmount,
                          amount1Max: maxAmount
                      });
                      IUniswapV3NonfungiblePositionManager(
                          lockedNFT.tokenAddress
                      ).collect(collectFeeParams);
                      //Uniswap emits event Collect(params.tokenId, recipient, amount0Collect, amount1Collect);
                  }
                  function _chargeFeesReferral(
                      address _tokenAddress,
                      address referrer
                  )
                  private
                  {
                      require(_msgSender() != referrer, "Refferer cant be msg sender");
                      uint256 feeInEth = getFeesInETH(_tokenAddress);
                      if (feeInEth == 0) {
                          if (msg.value > 0) {
                              (bool refundSuccess,) = _msgSender().call.value(msg.value)("");
                              require(refundSuccess, "Refund failed.");
                          }
                          return;
                      }
                      uint256 _referralDiscount = referralDiscount;
                      require(_referralDiscount > 0, "Refferal discount not set");
                      feeInEth = feeInEth.mul(referralDiscount).div(MAX_PERCENTAGE);
                      // will allow if diff is less than 5%
                      require(msg.value >= feeInEth.mul(95).div(100), "Fee Not Met");
                      uint256 takenFee = msg.value < feeInEth ? msg.value : feeInEth;
                      uint256 referrerFee = takenFee.mul(referrerCut).div(MAX_PERCENTAGE);
                      (bool referrerTransferSuccess,) = payable(referrer).call.value(referrerFee)("");
                      require(referrerTransferSuccess, "Referrer transfer failed.");
                      // cant overflow because referrerCut must be < MAX_PERCENTAGE -> referrerFee < takenFee
                      uint256 trustswapPart = takenFee - referrerFee;
                      (bool success,) = companyWallet.call.value(trustswapPart)("");
                      require(success, "Fee transfer failed");
                      /* refund difference. */
                      if (msg.value > takenFee) {
                          // cant overflow because takenFee < msg.value
                          (bool refundSuccess,) = _msgSender().call.value(msg.value - takenFee)("");
                          require(refundSuccess, "Refund failed");
                      }
                      emit ReferrerRewarded(referrer, referrerFee);
                  }
                  /**
                   */
                  function mintNFTforLock(uint256 _id)
                      external
                      whenNotPaused
                      nonReentrant
                  {
                      require(NFT != address(0), 'NFT: Unintalized');
                      require(
                          !nftMinted[_id], 
                          "NFT already minted"
                      );
                      NFTItems memory lockedNFT = lockedNFTs[_id];
                      Items memory lockedERC20 = lockedToken[_id];
                      require(
                          (lockedNFT.withdrawalAddress == _msgSender() || lockedERC20.withdrawalAddress == _msgSender()), 
                          "Unauthorised"
                      );
                      require((!lockedNFT.withdrawn && !lockedERC20.withdrawn), 
                          "Token/NFT already withdrawn"
                      );
                      _mintNFTforLock(_id, _msgSender());
                  }
                  function _mintNFTforLock(
                      uint256 _id, 
                      address _withdrawalAddress
                  ) 
                  private{
                      require(NFT != address(0), 'NFT: Unintalized');
                      nftMinted[_id] = true;
                      IERC721Extended(NFT).mintLiquidityLockNFT(_withdrawalAddress, _id);
                  }
                  /**
                   * @dev This function is used to setup a whitelistAdmin with the onlyOwner modifier
                   * @param account the account to assign the role to
                   * @param access to grank or revoke access
                  */
                  function updateWhitelistAdminAccess (
                      address account,
                      bool access
                  ) 
                  external  
                  onlyOwner {
                      whitelistAdmins[account] = access;
                      emit WhiteListAdminUpdated(account, access);
                  }
                  function recoverAssets(
                      address user, 
                      address newRecipient
                  ) external onlyOwner {
                      
                      require(user != address(0), "Invalid user address");
                      require(newRecipient != address(0), "Invalid new recipient address");
                      require(user != newRecipient, 'User and newRecipient address cannot be the same');
                      uint256[] memory userDeposits = depositsByWithdrawalAddress[user];
                      require(userDeposits.length > 0, "User has no deposits");
                      IERC721Extended _NFT = IERC721Extended(NFT);
                      for (uint i = 0; i < userDeposits.length; i++) {
                          uint256 _depositId = userDeposits[i];
                          Items storage item = lockedToken[_depositId];
                          NFTItems storage itemNFT = lockedNFTs[_depositId];
                          if (item.tokenAddress != address(0)) {
                              address tokenAddress = item.tokenAddress;
                              item.withdrawalAddress = newRecipient;
                              walletTokenBalance[tokenAddress][newRecipient] = walletTokenBalance[tokenAddress][newRecipient].add(item.tokenAmount);
                              walletTokenBalance[tokenAddress][user] = walletTokenBalance[tokenAddress][user].sub(item.tokenAmount);
                          } 
                          else if (itemNFT.tokenAddress != address(0)) {
                              address tokenAddress = itemNFT.tokenAddress;
                              itemNFT.withdrawalAddress = newRecipient;
                              walletTokenBalance[tokenAddress][newRecipient] = walletTokenBalance[tokenAddress][newRecipient].add(itemNFT.tokenAmount);
                              walletTokenBalance[tokenAddress][user] = walletTokenBalance[tokenAddress][user].sub(itemNFT.tokenAmount);
                          }
                          if(nftMinted[_depositId]) {
                              _NFT.burn(_depositId);
                              nftMinted[_depositId] = false;
                          }
                          depositsByWithdrawalAddress[newRecipient].push(_depositId);
                      }
                      depositsByWithdrawalAddress[user] = new uint256[](0);
                  }
              }pragma solidity ^0.6.0;
              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 ERC20;` 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));
                  }
                  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.
                      // A Solidity high level call has three parts:
                      //  1. The target address is checked to verify it contains contract code
                      //  2. The call itself is made, and success asserted
                      //  3. The return value is decoded, which in turn checks the size of the returned data.
                      // solhint-disable-next-line max-line-length
                      require(address(token).isContract(), "SafeERC20: call to non-contract");
                      // solhint-disable-next-line avoid-low-level-calls
                      (bool success, bytes memory returndata) = address(token).call(data);
                      require(success, "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 "../GSN/Context.sol";
              import "../Initializable.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              contract OwnableUpgradeSafe is Initializable, ContextUpgradeSafe {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  function __Ownable_init() internal initializer {
                      __Context_init_unchained();
                      __Ownable_init_unchained();
                  }
                  function __Ownable_init_unchained() internal initializer {
                      address msgSender = _msgSender();
                      _owner = msgSender;
                      emit OwnershipTransferred(address(0), msgSender);
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(_owner == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      emit OwnershipTransferred(_owner, address(0));
                      _owner = address(0);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      emit OwnershipTransferred(_owner, newOwner);
                      _owner = newOwner;
                  }
                  uint256[49] private __gap;
              }
              pragma solidity ^0.6.0;
              import "../GSN/Context.sol";
              import "../Initializable.sol";
              /**
               * @dev Contract module which allows children to implement an emergency stop
               * mechanism that can be triggered by an authorized account.
               *
               * This module is used through inheritance. It will make available the
               * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
               * the functions of your contract. Note that they will not be pausable by
               * simply including this module, only once the modifiers are put in place.
               */
              contract PausableUpgradeSafe is Initializable, ContextUpgradeSafe {
                  /**
                   * @dev Emitted when the pause is triggered by `account`.
                   */
                  event Paused(address account);
                  /**
                   * @dev Emitted when the pause is lifted by `account`.
                   */
                  event Unpaused(address account);
                  bool private _paused;
                  /**
                   * @dev Initializes the contract in unpaused state.
                   */
                  function __Pausable_init() internal initializer {
                      __Context_init_unchained();
                      __Pausable_init_unchained();
                  }
                  function __Pausable_init_unchained() internal initializer {
                      _paused = false;
                  }
                  /**
                   * @dev Returns true if the contract is paused, and false otherwise.
                   */
                  function paused() public view returns (bool) {
                      return _paused;
                  }
                  /**
                   * @dev Modifier to make a function callable only when the contract is not paused.
                   */
                  modifier whenNotPaused() {
                      require(!_paused, "Pausable: paused");
                      _;
                  }
                  /**
                   * @dev Modifier to make a function callable only when the contract is paused.
                   */
                  modifier whenPaused() {
                      require(_paused, "Pausable: not paused");
                      _;
                  }
                  /**
                   * @dev Triggers stopped state.
                   */
                  function _pause() internal virtual whenNotPaused {
                      _paused = true;
                      emit Paused(_msgSender());
                  }
                  /**
                   * @dev Returns to normal state.
                   */
                  function _unpause() internal virtual whenPaused {
                      _paused = false;
                      emit Unpaused(_msgSender());
                  }
                  uint256[49] private __gap;
              }
              pragma solidity ^0.6.0;
              /**
               * @title ERC721 token receiver interface
               * @dev Interface for any contract that wants to support safeTransfers
               * from ERC721 asset contracts.
               */
              interface IERC721Receiver {
                  /**
                   * @notice Handle the receipt of an NFT
                   * @dev The ERC721 smart contract calls this function on the recipient
                   * after a {IERC721-safeTransferFrom}. This function MUST return the function selector,
                   * otherwise the caller will revert the transaction. The selector to be
                   * returned can be obtained as `this.onERC721Received.selector`. This
                   * function MAY throw to revert and reject the transfer.
                   * Note: the ERC721 contract address is always the message sender.
                   * @param operator The address which called `safeTransferFrom` function
                   * @param from The address which previously owned the token
                   * @param tokenId The NFT identifier which is being transferred
                   * @param data Additional data with no specified format
                   * @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
                   */
                  function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data)
                  external returns (bytes4);
              }
              pragma solidity ^0.6.2;
              import "./IERC721.sol";
              /**
               * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
               * @dev See https://eips.ethereum.org/EIPS/eip-721
               */
              interface IERC721Enumerable is IERC721 {
                  function totalSupply() external view returns (uint256);
                  function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
                  function tokenByIndex(uint256 index) external view returns (uint256);
              }
              pragma solidity 0.6.2;
              interface IERC20Extended {
                  function decimals() external view returns (uint8);
              }pragma solidity 0.6.2;
              interface IPriceEstimator {
                  function getEstimatedETHforERC20(
                      uint256 erc20Amount,
                      address token
                  ) external view returns (uint256[] memory);
                  function getEstimatedERC20forETH(
                      uint256 etherAmountInWei,
                      address tokenAddress
                  ) external view returns (uint256[] memory);
                  function getFeeInETHWithOracle(
                      uint256 _feesInUSD
                  ) external view returns (uint256);
                  function setOracleParams(address _dataFeed, bool _useOracle) external;
                  function getUseOracle() external view returns (bool);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity 0.6.2;
              pragma experimental ABIEncoderV2;
              /// @title V3 Migrator
              /// @notice Enables migration of liqudity from Uniswap v2-compatible pairs into Uniswap v3 pools
              interface IV3Migrator {
                  struct MigrateParams {
                      address pair; // the Uniswap v2-compatible pair
                      uint256 liquidityToMigrate; // expected to be balanceOf(msg.sender)
                      uint8 percentageToMigrate; // represented as a numerator over 100
                      address token0;
                      address token1;
                      uint24 fee;
                      int24 tickLower;
                      int24 tickUpper;
                      uint256 amount0Min; // must be discounted by percentageToMigrate
                      uint256 amount1Min; // must be discounted by percentageToMigrate
                      address recipient;
                      uint256 deadline;
                      bool refundAsETH;
                  }
                  /// @notice Migrates liquidity to v3 by burning v2 liquidity and minting a new position for v3
                  /// @dev Slippage protection is enforced via `amount{0,1}Min`, which should be a discount of the expected values of
                  /// the maximum amount of v3 liquidity that the v2 liquidity can get. For the special case of migrating to an
                  /// out-of-range position, `amount{0,1}Min` may be set to 0, enforcing that the position remains out of range
                  /// @param params The params necessary to migrate v2 liquidity, encoded as `MigrateParams` in calldata
                  function migrate(MigrateParams calldata params) external;
                  /// @notice Creates a new pool if it does not exist, then initializes if not initialized
                  /// @dev This method can be bundled with others via IMulticall for the first action (e.g. mint) performed against a pool
                  /// @param token0 The contract address of token0 of the pool
                  /// @param token1 The contract address of token1 of the pool
                  /// @param fee The fee amount of the v3 pool for the specified token pair
                  /// @param sqrtPriceX96 The initial square root price of the pool as a Q64.96 value
                  /// @return pool Returns the pool address based on the pair of tokens and fee, will return the newly created pool address if necessary
                  function createAndInitializePoolIfNecessary(
                      address token0,
                      address token1,
                      uint24 fee,
                      uint160 sqrtPriceX96
                  ) external payable returns (address pool);
              }
              pragma solidity 0.6.2;
              import "@openzeppelin/contracts-ethereum-package/contracts/token/ERC721/IERC721.sol";
              interface IERC721Extended is IERC721 {
                  function mintLiquidityLockNFT(address _to, uint256 _tokenId) external;
                  function burn (uint256 _tokenId) external;
                  function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
                  function transferOwnership (address _newOwner) external;
              }pragma solidity 0.6.2;
              pragma experimental ABIEncoderV2;
              interface IUniswapV3NonfungiblePositionManager {
                  struct CollectParams {
                      uint256 tokenId;
                      address recipient;
                      uint128 amount0Max;
                      uint128 amount1Max;
                  }
                  /// @notice Collects up to a maximum amount of fees owed to a specific position to the recipient
                  /// @param params tokenId The ID of the NFT for which tokens are being collected,
                  /// recipient The account that should receive the tokens,
                  /// amount0Max The maximum amount of token0 to collect,
                  /// amount1Max The maximum amount of token1 to collect
                  /// @return amount0 The amount of fees collected in token0
                  /// @return amount1 The amount of fees collected in token1
                  function collect(
                      CollectParams calldata params
                  ) external 
                  payable 
                  returns (
                      uint256 amount0, 
                      uint256 amount1
                  );
              }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);
              }
              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) {
                      // 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;
                  }
              }
              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) {
                      // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
                      // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
                      // for accounts without code, i.e. `keccak256('')`
                      bytes32 codehash;
                      bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
                      // solhint-disable-next-line no-inline-assembly
                      assembly { codehash := extcodehash(account) }
                      return (codehash != accountHash && codehash != 0x0);
                  }
                  /**
                   * @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");
                  }
              }
              pragma solidity ^0.6.0;
              import "../Initializable.sol";
              /*
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with GSN meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              contract ContextUpgradeSafe is Initializable {
                  // Empty internal constructor, to prevent people from mistakenly deploying
                  // an instance of this contract, which should be used via inheritance.
                  function __Context_init() internal initializer {
                      __Context_init_unchained();
                  }
                  function __Context_init_unchained() internal initializer {
                  }
                  function _msgSender() internal view virtual returns (address payable) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes memory) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
                  uint256[50] private __gap;
              }
              pragma solidity >=0.4.24 <0.7.0;
              /**
               * @title Initializable
               *
               * @dev Helper contract to support initializer functions. To use it, replace
               * the constructor with a function that has the `initializer` modifier.
               * WARNING: Unlike constructors, initializer functions must be manually
               * invoked. This applies both to deploying an Initializable contract, as well
               * as extending an Initializable contract via inheritance.
               * WARNING: When used with inheritance, manual care must be taken to not invoke
               * a parent initializer twice, or ensure that all initializers are idempotent,
               * because this is not dealt with automatically as with constructors.
               */
              contract Initializable {
                /**
                 * @dev Indicates that the contract has been initialized.
                 */
                bool private initialized;
                /**
                 * @dev Indicates that the contract is in the process of being initialized.
                 */
                bool private initializing;
                /**
                 * @dev Modifier to use in the initializer function of a contract.
                 */
                modifier initializer() {
                  require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");
                  bool isTopLevelCall = !initializing;
                  if (isTopLevelCall) {
                    initializing = true;
                    initialized = true;
                  }
                  _;
                  if (isTopLevelCall) {
                    initializing = false;
                  }
                }
                /// @dev Returns true if and only if the function is running in the constructor
                function isConstructor() private view returns (bool) {
                  // extcodesize checks the size of the code stored in an address, and
                  // address returns the current address. Since the code is still not
                  // deployed when running a constructor, any checks on its code size will
                  // yield zero, making it an effective way to detect if a contract is
                  // under construction or not.
                  address self = address(this);
                  uint256 cs;
                  assembly { cs := extcodesize(self) }
                  return cs == 0;
                }
                // Reserved storage space to allow for layout changes in the future.
                uint256[50] private ______gap;
              }
              pragma solidity ^0.6.2;
              import "../../introspection/IERC165.sol";
              /**
               * @dev Required interface of an ERC721 compliant contract.
               */
              interface IERC721 is IERC165 {
                  event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
                  event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
                  event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
                  /**
                   * @dev Returns the number of NFTs in ``owner``'s account.
                   */
                  function balanceOf(address owner) external view returns (uint256 balance);
                  /**
                   * @dev Returns the owner of the NFT specified by `tokenId`.
                   */
                  function ownerOf(uint256 tokenId) external view returns (address owner);
                  /**
                   * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
                   * another (`to`).
                   *
                   *
                   *
                   * Requirements:
                   * - `from`, `to` cannot be zero.
                   * - `tokenId` must be owned by `from`.
                   * - If the caller is not `from`, it must be have been allowed to move this
                   * NFT by either {approve} or {setApprovalForAll}.
                   */
                  function safeTransferFrom(address from, address to, uint256 tokenId) external;
                  /**
                   * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
                   * another (`to`).
                   *
                   * Requirements:
                   * - If the caller is not `from`, it must be approved to move this NFT by
                   * either {approve} or {setApprovalForAll}.
                   */
                  function transferFrom(address from, address to, uint256 tokenId) external;
                  function approve(address to, uint256 tokenId) external;
                  function getApproved(uint256 tokenId) external view returns (address operator);
                  function setApprovalForAll(address operator, bool _approved) external;
                  function isApprovedForAll(address owner, address operator) external view returns (bool);
                  function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
              }
              pragma solidity ^0.6.0;
              /**
               * @dev Interface of the ERC165 standard, as defined in the
               * https://eips.ethereum.org/EIPS/eip-165[EIP].
               *
               * Implementers can declare support of contract interfaces, which can then be
               * queried by others ({ERC165Checker}).
               *
               * For an implementation, see {ERC165}.
               */
              interface IERC165 {
                  /**
                   * @dev Returns true if this contract implements the interface defined by
                   * `interfaceId`. See the corresponding
                   * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
                   * to learn more about how these ids are created.
                   *
                   * This function call must use less than 30 000 gas.
                   */
                  function supportsInterface(bytes4 interfaceId) external view returns (bool);
              }
              

              File 4 of 7: TransparentUpgradeableProxy
              // 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 admin_) {
                      admin_ = _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 implementation_) {
                      implementation_ = _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 virtual 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 virtual 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 virtual ifAdmin {
                      _upgradeTo(newImplementation);
                      Address.functionDelegateCall(newImplementation, data);
                  }
                  /**
                   * @dev Returns the current admin.
                   */
                  function _admin() internal view virtual 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 virtual override {
                      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 "./Proxy.sol";
              import "../utils/Address.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) {
                          Address.functionDelegateCall(_logic, _data);
                      }
                  }
                  /**
                   * @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 view virtual override 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 virtual {
                      _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 virtual {
                      // 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 view virtual 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 virtual {
                      _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 () external payable virtual {
                      _fallback();
                  }
                  /**
                   * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                   * is empty.
                   */
                  receive () external payable virtual {
                      _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 {
                  }
              }
              // 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);
                          }
                      }
                  }
              }
              

              File 5 of 7: PriceEstimator
              pragma solidity 0.6.2;
              import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol";
              import "@openzeppelin/contracts-ethereum-package/contracts/access/Ownable.sol";
              import "@openzeppelin/contracts-ethereum-package/contracts/utils/Address.sol";
              import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";
              import "./interfaces/IPriceEstimator.sol";
              contract PriceEstimator is IPriceEstimator, Initializable, OwnableUpgradeSafe {
                  using Address for address;
                  IUniswapV2Router02 internal uniswapRouter;
                  AggregatorV3Interface internal dataFeed;
                  bool public useOracle;
                  event SettingsUpdated(address priceAggregatorAddress, bool useOracle);
                  modifier onlyContract(address account) {
                      require(
                          account.isContract(),
                          "[Validation] The address does not contain a contract"
                      );
                      _;
                  }
                  function initialize(
                      address uniswapOrOracleAddress,
                      bool _useOracle
                  ) external onlyContract(uniswapOrOracleAddress) {
                      __PriceEstimator_init(uniswapOrOracleAddress, _useOracle);
                  }
                  function __PriceEstimator_init(
                      address uniswapOrOracleAddress,
                      bool _useOracle
                  ) internal initializer {
                      __Context_init_unchained();
                      __Ownable_init_unchained();
                      if (_useOracle) {
                          dataFeed = AggregatorV3Interface(uniswapOrOracleAddress);
                      } else {
                          uniswapRouter = IUniswapV2Router02(uniswapOrOracleAddress);
                      }
                      useOracle = _useOracle;
                  }
                  /// @notice Set Price estimator to use dex router.
                  /// @param uniswapRouterAddress The dex router to use.
                  /// @param _useOracle flag for using oracle, set false for dex router.
                  function setUniswapRouter(
                      address uniswapRouterAddress,
                      bool _useOracle
                  ) external onlyOwner onlyContract(uniswapRouterAddress) {
                      require(
                          uniswapRouterAddress != address(0),
                          "[Validation]: Invalid uniswap router address"
                      );
                      uniswapRouter = IUniswapV2Router02(uniswapRouterAddress);
                      useOracle = _useOracle;
                      emit SettingsUpdated(uniswapRouterAddress, _useOracle);
                  }
                  function getEstimatedETHforERC20(
                      uint256 erc20Amount,
                      address tokenAddress
                  ) external view override returns (uint256[] memory) {
                      return
                          uniswapRouter.getAmountsIn(
                              erc20Amount,
                              getPathForETHtoERC20(tokenAddress)
                          );
                  }
                  function getPathForETHtoERC20(
                      address tokenAddress
                  ) internal view returns (address[] memory) {
                      address[] memory path = new address[](2);
                      path[0] = uniswapRouter.WETH();
                      path[1] = tokenAddress;
                      return path;
                  }
                  function getUseOracle() external view override returns (bool) {
                      return useOracle;
                  }
                  function getEstimatedERC20forETH(
                      uint256 etherAmount,
                      address tokenAddress
                  ) external view override returns (uint256[] memory) {
                      return
                          uniswapRouter.getAmountsIn(
                              etherAmount,
                              getPathForERC20toETH(tokenAddress)
                          );
                  }
                  function getPathForERC20toETH(
                      address tokenAddress
                  ) internal view returns (address[] memory) {
                      address[] memory path = new address[](2);
                      path[0] = tokenAddress;
                      path[1] = uniswapRouter.WETH();
                      return path;
                  }
                  /// @notice Set Price estimator to use oracle feed.
                  /// @param _dataFeed The chainlink feed to use.
                  /// @param _useOracle flag for using _dataFeed, set true to use data feed.
                  function setOracleParams(
                      address _dataFeed,
                      bool _useOracle
                  ) external override onlyOwner onlyContract(_dataFeed) {
                      require(address(_dataFeed) != address(0), "dataFeed is zero address");
                      useOracle = _useOracle;
                      dataFeed = AggregatorV3Interface(_dataFeed);
                      emit SettingsUpdated(_dataFeed, _useOracle);
                  }
                  /// @notice Retrieves the current fee amount in ETH for a given token.
                  /// @param _feesInUSD The Fees in USD.
                  /// @return The calculated fee amount in ETH.
                  /// @dev Uses the Chainlink data feed to get the latest ETH price for fee calculation.
                  function getFeeInETHWithOracle(
                      uint256 _feesInUSD
                  ) external view override returns (uint256) {
                      (
                          ,
                          /* uint80 roundID */ int answer /*uint startedAt*/ /*uint timeStamp*/ /*uint80 answeredInRound*/,
                          ,
                          ,
                      ) = dataFeed.latestRoundData();
                      // multiply by 100 to keep decimals same with uniswap router response
                      return ((_feesInUSD * 10 ** 18) / uint256(answer)) * 100;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.6.0;
              interface AggregatorV3Interface {
                function decimals()
                  external
                  view
                  returns (
                    uint8
                  );
                function description()
                  external
                  view
                  returns (
                    string memory
                  );
                function version()
                  external
                  view
                  returns (
                    uint256
                  );
                function getRoundData(
                  uint80 _roundId
                )
                  external
                  view
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  );
                function latestRoundData()
                  external
                  view
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  );
              }
              pragma solidity ^0.6.0;
              import "../GSN/Context.sol";
              import "../Initializable.sol";
              /**
               * @dev Contract module which provides a basic access control mechanism, where
               * there is an account (an owner) that can be granted exclusive access to
               * specific functions.
               *
               * By default, the owner account will be the one that deploys the contract. This
               * can later be changed with {transferOwnership}.
               *
               * This module is used through inheritance. It will make available the modifier
               * `onlyOwner`, which can be applied to your functions to restrict their use to
               * the owner.
               */
              contract OwnableUpgradeSafe is Initializable, ContextUpgradeSafe {
                  address private _owner;
                  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                  /**
                   * @dev Initializes the contract setting the deployer as the initial owner.
                   */
                  function __Ownable_init() internal initializer {
                      __Context_init_unchained();
                      __Ownable_init_unchained();
                  }
                  function __Ownable_init_unchained() internal initializer {
                      address msgSender = _msgSender();
                      _owner = msgSender;
                      emit OwnershipTransferred(address(0), msgSender);
                  }
                  /**
                   * @dev Returns the address of the current owner.
                   */
                  function owner() public view returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(_owner == _msgSender(), "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Leaves the contract without owner. It will not be possible to call
                   * `onlyOwner` functions anymore. Can only be called by the current owner.
                   *
                   * NOTE: Renouncing ownership will leave the contract without an owner,
                   * thereby removing any functionality that is only available to the owner.
                   */
                  function renounceOwnership() public virtual onlyOwner {
                      emit OwnershipTransferred(_owner, address(0));
                      _owner = address(0);
                  }
                  /**
                   * @dev Transfers ownership of the contract to a new account (`newOwner`).
                   * Can only be called by the current owner.
                   */
                  function transferOwnership(address newOwner) public virtual onlyOwner {
                      require(newOwner != address(0), "Ownable: new owner is the zero address");
                      emit OwnershipTransferred(_owner, newOwner);
                      _owner = newOwner;
                  }
                  uint256[49] private __gap;
              }
              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) {
                      // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
                      // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
                      // for accounts without code, i.e. `keccak256('')`
                      bytes32 codehash;
                      bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
                      // solhint-disable-next-line no-inline-assembly
                      assembly { codehash := extcodehash(account) }
                      return (codehash != accountHash && codehash != 0x0);
                  }
                  /**
                   * @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");
                  }
              }
              pragma solidity >=0.6.2;
              import './IUniswapV2Router01.sol';
              interface IUniswapV2Router02 is IUniswapV2Router01 {
                  function removeLiquidityETHSupportingFeeOnTransferTokens(
                      address token,
                      uint liquidity,
                      uint amountTokenMin,
                      uint amountETHMin,
                      address to,
                      uint deadline
                  ) external returns (uint amountETH);
                  function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
                      address token,
                      uint liquidity,
                      uint amountTokenMin,
                      uint amountETHMin,
                      address to,
                      uint deadline,
                      bool approveMax, uint8 v, bytes32 r, bytes32 s
                  ) external returns (uint amountETH);
                  function swapExactTokensForTokensSupportingFeeOnTransferTokens(
                      uint amountIn,
                      uint amountOutMin,
                      address[] calldata path,
                      address to,
                      uint deadline
                  ) external;
                  function swapExactETHForTokensSupportingFeeOnTransferTokens(
                      uint amountOutMin,
                      address[] calldata path,
                      address to,
                      uint deadline
                  ) external payable;
                  function swapExactTokensForETHSupportingFeeOnTransferTokens(
                      uint amountIn,
                      uint amountOutMin,
                      address[] calldata path,
                      address to,
                      uint deadline
                  ) external;
              }
              pragma solidity 0.6.2;
              interface IPriceEstimator {
                  function getEstimatedETHforERC20(
                      uint256 erc20Amount,
                      address token
                  ) external view returns (uint256[] memory);
                  function getEstimatedERC20forETH(
                      uint256 etherAmountInWei,
                      address tokenAddress
                  ) external view returns (uint256[] memory);
                  function getFeeInETHWithOracle(
                      uint256 _feesInUSD
                  ) external view returns (uint256);
                  function setOracleParams(address _dataFeed, bool _useOracle) external;
                  function getUseOracle() external view returns (bool);
              }
              pragma solidity ^0.6.0;
              import "../Initializable.sol";
              /*
               * @dev Provides information about the current execution context, including the
               * sender of the transaction and its data. While these are generally available
               * via msg.sender and msg.data, they should not be accessed in such a direct
               * manner, since when dealing with GSN meta-transactions the account sending and
               * paying for execution may not be the actual sender (as far as an application
               * is concerned).
               *
               * This contract is only required for intermediate, library-like contracts.
               */
              contract ContextUpgradeSafe is Initializable {
                  // Empty internal constructor, to prevent people from mistakenly deploying
                  // an instance of this contract, which should be used via inheritance.
                  function __Context_init() internal initializer {
                      __Context_init_unchained();
                  }
                  function __Context_init_unchained() internal initializer {
                  }
                  function _msgSender() internal view virtual returns (address payable) {
                      return msg.sender;
                  }
                  function _msgData() internal view virtual returns (bytes memory) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
                  uint256[50] private __gap;
              }
              pragma solidity >=0.4.24 <0.7.0;
              /**
               * @title Initializable
               *
               * @dev Helper contract to support initializer functions. To use it, replace
               * the constructor with a function that has the `initializer` modifier.
               * WARNING: Unlike constructors, initializer functions must be manually
               * invoked. This applies both to deploying an Initializable contract, as well
               * as extending an Initializable contract via inheritance.
               * WARNING: When used with inheritance, manual care must be taken to not invoke
               * a parent initializer twice, or ensure that all initializers are idempotent,
               * because this is not dealt with automatically as with constructors.
               */
              contract Initializable {
                /**
                 * @dev Indicates that the contract has been initialized.
                 */
                bool private initialized;
                /**
                 * @dev Indicates that the contract is in the process of being initialized.
                 */
                bool private initializing;
                /**
                 * @dev Modifier to use in the initializer function of a contract.
                 */
                modifier initializer() {
                  require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");
                  bool isTopLevelCall = !initializing;
                  if (isTopLevelCall) {
                    initializing = true;
                    initialized = true;
                  }
                  _;
                  if (isTopLevelCall) {
                    initializing = false;
                  }
                }
                /// @dev Returns true if and only if the function is running in the constructor
                function isConstructor() private view returns (bool) {
                  // extcodesize checks the size of the code stored in an address, and
                  // address returns the current address. Since the code is still not
                  // deployed when running a constructor, any checks on its code size will
                  // yield zero, making it an effective way to detect if a contract is
                  // under construction or not.
                  address self = address(this);
                  uint256 cs;
                  assembly { cs := extcodesize(self) }
                  return cs == 0;
                }
                // Reserved storage space to allow for layout changes in the future.
                uint256[50] private ______gap;
              }
              pragma solidity >=0.6.2;
              interface IUniswapV2Router01 {
                  function factory() external pure returns (address);
                  function WETH() external pure returns (address);
                  function addLiquidity(
                      address tokenA,
                      address tokenB,
                      uint amountADesired,
                      uint amountBDesired,
                      uint amountAMin,
                      uint amountBMin,
                      address to,
                      uint deadline
                  ) external returns (uint amountA, uint amountB, uint liquidity);
                  function addLiquidityETH(
                      address token,
                      uint amountTokenDesired,
                      uint amountTokenMin,
                      uint amountETHMin,
                      address to,
                      uint deadline
                  ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
                  function removeLiquidity(
                      address tokenA,
                      address tokenB,
                      uint liquidity,
                      uint amountAMin,
                      uint amountBMin,
                      address to,
                      uint deadline
                  ) external returns (uint amountA, uint amountB);
                  function removeLiquidityETH(
                      address token,
                      uint liquidity,
                      uint amountTokenMin,
                      uint amountETHMin,
                      address to,
                      uint deadline
                  ) external returns (uint amountToken, uint amountETH);
                  function removeLiquidityWithPermit(
                      address tokenA,
                      address tokenB,
                      uint liquidity,
                      uint amountAMin,
                      uint amountBMin,
                      address to,
                      uint deadline,
                      bool approveMax, uint8 v, bytes32 r, bytes32 s
                  ) external returns (uint amountA, uint amountB);
                  function removeLiquidityETHWithPermit(
                      address token,
                      uint liquidity,
                      uint amountTokenMin,
                      uint amountETHMin,
                      address to,
                      uint deadline,
                      bool approveMax, uint8 v, bytes32 r, bytes32 s
                  ) external returns (uint amountToken, uint amountETH);
                  function swapExactTokensForTokens(
                      uint amountIn,
                      uint amountOutMin,
                      address[] calldata path,
                      address to,
                      uint deadline
                  ) external returns (uint[] memory amounts);
                  function swapTokensForExactTokens(
                      uint amountOut,
                      uint amountInMax,
                      address[] calldata path,
                      address to,
                      uint deadline
                  ) external returns (uint[] memory amounts);
                  function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
                      external
                      payable
                      returns (uint[] memory amounts);
                  function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
                      external
                      returns (uint[] memory amounts);
                  function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
                      external
                      returns (uint[] memory amounts);
                  function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
                      external
                      payable
                      returns (uint[] memory amounts);
                  function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
                  function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
                  function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
                  function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
                  function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
              }
              

              File 6 of 7: EACAggregatorProxy
              pragma solidity 0.6.6;
              
              
              /**
               * @title The Owned contract
               * @notice A contract with helpers for basic contract ownership.
               */
              contract Owned {
              
                address payable public owner;
                address private pendingOwner;
              
                event OwnershipTransferRequested(
                  address indexed from,
                  address indexed to
                );
                event OwnershipTransferred(
                  address indexed from,
                  address indexed to
                );
              
                constructor() public {
                  owner = msg.sender;
                }
              
                /**
                 * @dev Allows an owner to begin transferring ownership to a new address,
                 * pending.
                 */
                function transferOwnership(address _to)
                  external
                  onlyOwner()
                {
                  pendingOwner = _to;
              
                  emit OwnershipTransferRequested(owner, _to);
                }
              
                /**
                 * @dev Allows an ownership transfer to be completed by the recipient.
                 */
                function acceptOwnership()
                  external
                {
                  require(msg.sender == pendingOwner, "Must be proposed owner");
              
                  address oldOwner = owner;
                  owner = msg.sender;
                  pendingOwner = address(0);
              
                  emit OwnershipTransferred(oldOwner, msg.sender);
                }
              
                /**
                 * @dev Reverts if called by anyone other than the contract owner.
                 */
                modifier onlyOwner() {
                  require(msg.sender == owner, "Only callable by owner");
                  _;
                }
              
              }
              
              interface AggregatorInterface {
                function latestAnswer() external view returns (int256);
                function latestTimestamp() external view returns (uint256);
                function latestRound() external view returns (uint256);
                function getAnswer(uint256 roundId) external view returns (int256);
                function getTimestamp(uint256 roundId) external view returns (uint256);
              
                event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);
                event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
              }
              
              interface AggregatorV3Interface {
              
                function decimals() external view returns (uint8);
                function description() external view returns (string memory);
                function version() external view returns (uint256);
              
                // getRoundData and latestRoundData should both raise "No data present"
                // if they do not have data to report, instead of returning unset values
                // which could be misinterpreted as actual reported values.
                function getRoundData(uint80 _roundId)
                  external
                  view
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  );
                function latestRoundData()
                  external
                  view
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  );
              
              }
              
              interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface
              {
              }
              
              /**
               * @title A trusted proxy for updating where current answers are read from
               * @notice This contract provides a consistent address for the
               * CurrentAnwerInterface but delegates where it reads from to the owner, who is
               * trusted to update it.
               */
              contract AggregatorProxy is AggregatorV2V3Interface, Owned {
              
                struct Phase {
                  uint16 id;
                  AggregatorV2V3Interface aggregator;
                }
                Phase private currentPhase;
                AggregatorV2V3Interface public proposedAggregator;
                mapping(uint16 => AggregatorV2V3Interface) public phaseAggregators;
              
                uint256 constant private PHASE_OFFSET = 64;
                uint256 constant private PHASE_SIZE = 16;
                uint256 constant private MAX_ID = 2**(PHASE_OFFSET+PHASE_SIZE) - 1;
              
                constructor(address _aggregator) public Owned() {
                  setAggregator(_aggregator);
                }
              
                /**
                 * @notice Reads the current answer from aggregator delegated to.
                 *
                 * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended latestRoundData
                 * instead which includes better verification information.
                 */
                function latestAnswer()
                  public
                  view
                  virtual
                  override
                  returns (int256 answer)
                {
                  return currentPhase.aggregator.latestAnswer();
                }
              
                /**
                 * @notice Reads the last updated height from aggregator delegated to.
                 *
                 * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended latestRoundData
                 * instead which includes better verification information.
                 */
                function latestTimestamp()
                  public
                  view
                  virtual
                  override
                  returns (uint256 updatedAt)
                {
                  return currentPhase.aggregator.latestTimestamp();
                }
              
                /**
                 * @notice get past rounds answers
                 * @param _roundId the answer number to retrieve the answer for
                 *
                 * @dev #[deprecated] Use getRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended getRoundData
                 * instead which includes better verification information.
                 */
                function getAnswer(uint256 _roundId)
                  public
                  view
                  virtual
                  override
                  returns (int256 answer)
                {
                  if (_roundId > MAX_ID) return 0;
              
                  (uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
                  AggregatorV2V3Interface aggregator = phaseAggregators[phaseId];
                  if (address(aggregator) == address(0)) return 0;
              
                  return aggregator.getAnswer(aggregatorRoundId);
                }
              
                /**
                 * @notice get block timestamp when an answer was last updated
                 * @param _roundId the answer number to retrieve the updated timestamp for
                 *
                 * @dev #[deprecated] Use getRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended getRoundData
                 * instead which includes better verification information.
                 */
                function getTimestamp(uint256 _roundId)
                  public
                  view
                  virtual
                  override
                  returns (uint256 updatedAt)
                {
                  if (_roundId > MAX_ID) return 0;
              
                  (uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
                  AggregatorV2V3Interface aggregator = phaseAggregators[phaseId];
                  if (address(aggregator) == address(0)) return 0;
              
                  return aggregator.getTimestamp(aggregatorRoundId);
                }
              
                /**
                 * @notice get the latest completed round where the answer was updated. This
                 * ID includes the proxy's phase, to make sure round IDs increase even when
                 * switching to a newly deployed aggregator.
                 *
                 * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended latestRoundData
                 * instead which includes better verification information.
                 */
                function latestRound()
                  public
                  view
                  virtual
                  override
                  returns (uint256 roundId)
                {
                  Phase memory phase = currentPhase; // cache storage reads
                  return addPhase(phase.id, uint64(phase.aggregator.latestRound()));
                }
              
                /**
                 * @notice get data about a round. Consumers are encouraged to check
                 * that they're receiving fresh data by inspecting the updatedAt and
                 * answeredInRound return values.
                 * Note that different underlying implementations of AggregatorV3Interface
                 * have slightly different semantics for some of the return values. Consumers
                 * should determine what implementations they expect to receive
                 * data from and validate that they can properly handle return data from all
                 * of them.
                 * @param _roundId the requested round ID as presented through the proxy, this
                 * is made up of the aggregator's round ID with the phase ID encoded in the
                 * two highest order bytes
                 * @return roundId is the round ID from the aggregator for which the data was
                 * retrieved combined with an phase to ensure that round IDs get larger as
                 * time moves forward.
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @dev Note that answer and updatedAt may change between queries.
                 */
                function getRoundData(uint80 _roundId)
                  public
                  view
                  virtual
                  override
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  (uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
              
                  (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 ansIn
                  ) = phaseAggregators[phaseId].getRoundData(aggregatorRoundId);
              
                  return addPhaseIds(roundId, answer, startedAt, updatedAt, ansIn, phaseId);
                }
              
                /**
                 * @notice get data about the latest round. Consumers are encouraged to check
                 * that they're receiving fresh data by inspecting the updatedAt and
                 * answeredInRound return values.
                 * Note that different underlying implementations of AggregatorV3Interface
                 * have slightly different semantics for some of the return values. Consumers
                 * should determine what implementations they expect to receive
                 * data from and validate that they can properly handle return data from all
                 * of them.
                 * @return roundId is the round ID from the aggregator for which the data was
                 * retrieved combined with an phase to ensure that round IDs get larger as
                 * time moves forward.
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @dev Note that answer and updatedAt may change between queries.
                 */
                function latestRoundData()
                  public
                  view
                  virtual
                  override
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  Phase memory current = currentPhase; // cache storage reads
              
                  (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 ansIn
                  ) = current.aggregator.latestRoundData();
              
                  return addPhaseIds(roundId, answer, startedAt, updatedAt, ansIn, current.id);
                }
              
                /**
                 * @notice Used if an aggregator contract has been proposed.
                 * @param _roundId the round ID to retrieve the round data for
                 * @return roundId is the round ID for which data was retrieved
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                */
                function proposedGetRoundData(uint80 _roundId)
                  public
                  view
                  virtual
                  hasProposal()
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return proposedAggregator.getRoundData(_roundId);
                }
              
                /**
                 * @notice Used if an aggregator contract has been proposed.
                 * @return roundId is the round ID for which data was retrieved
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                */
                function proposedLatestRoundData()
                  public
                  view
                  virtual
                  hasProposal()
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return proposedAggregator.latestRoundData();
                }
              
                /**
                 * @notice returns the current phase's aggregator address.
                 */
                function aggregator()
                  external
                  view
                  returns (address)
                {
                  return address(currentPhase.aggregator);
                }
              
                /**
                 * @notice returns the current phase's ID.
                 */
                function phaseId()
                  external
                  view
                  returns (uint16)
                {
                  return currentPhase.id;
                }
              
                /**
                 * @notice represents the number of decimals the aggregator responses represent.
                 */
                function decimals()
                  external
                  view
                  override
                  returns (uint8)
                {
                  return currentPhase.aggregator.decimals();
                }
              
                /**
                 * @notice the version number representing the type of aggregator the proxy
                 * points to.
                 */
                function version()
                  external
                  view
                  override
                  returns (uint256)
                {
                  return currentPhase.aggregator.version();
                }
              
                /**
                 * @notice returns the description of the aggregator the proxy points to.
                 */
                function description()
                  external
                  view
                  override
                  returns (string memory)
                {
                  return currentPhase.aggregator.description();
                }
              
                /**
                 * @notice Allows the owner to propose a new address for the aggregator
                 * @param _aggregator The new address for the aggregator contract
                 */
                function proposeAggregator(address _aggregator)
                  external
                  onlyOwner()
                {
                  proposedAggregator = AggregatorV2V3Interface(_aggregator);
                }
              
                /**
                 * @notice Allows the owner to confirm and change the address
                 * to the proposed aggregator
                 * @dev Reverts if the given address doesn't match what was previously
                 * proposed
                 * @param _aggregator The new address for the aggregator contract
                 */
                function confirmAggregator(address _aggregator)
                  external
                  onlyOwner()
                {
                  require(_aggregator == address(proposedAggregator), "Invalid proposed aggregator");
                  delete proposedAggregator;
                  setAggregator(_aggregator);
                }
              
              
                /*
                 * Internal
                 */
              
                function setAggregator(address _aggregator)
                  internal
                {
                  uint16 id = currentPhase.id + 1;
                  currentPhase = Phase(id, AggregatorV2V3Interface(_aggregator));
                  phaseAggregators[id] = AggregatorV2V3Interface(_aggregator);
                }
              
                function addPhase(
                  uint16 _phase,
                  uint64 _originalId
                )
                  internal
                  view
                  returns (uint80)
                {
                  return uint80(uint256(_phase) << PHASE_OFFSET | _originalId);
                }
              
                function parseIds(
                  uint256 _roundId
                )
                  internal
                  view
                  returns (uint16, uint64)
                {
                  uint16 phaseId = uint16(_roundId >> PHASE_OFFSET);
                  uint64 aggregatorRoundId = uint64(_roundId);
              
                  return (phaseId, aggregatorRoundId);
                }
              
                function addPhaseIds(
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound,
                    uint16 phaseId
                )
                  internal
                  view
                  returns (uint80, int256, uint256, uint256, uint80)
                {
                  return (
                    addPhase(phaseId, uint64(roundId)),
                    answer,
                    startedAt,
                    updatedAt,
                    addPhase(phaseId, uint64(answeredInRound))
                  );
                }
              
                /*
                 * Modifiers
                 */
              
                modifier hasProposal() {
                  require(address(proposedAggregator) != address(0), "No proposed aggregator present");
                  _;
                }
              
              }
              
              interface AccessControllerInterface {
                function hasAccess(address user, bytes calldata data) external view returns (bool);
              }
              
              /**
               * @title External Access Controlled Aggregator Proxy
               * @notice A trusted proxy for updating where current answers are read from
               * @notice This contract provides a consistent address for the
               * Aggregator and AggregatorV3Interface but delegates where it reads from to the owner, who is
               * trusted to update it.
               * @notice Only access enabled addresses are allowed to access getters for
               * aggregated answers and round information.
               */
              contract EACAggregatorProxy is AggregatorProxy {
              
                AccessControllerInterface public accessController;
              
                constructor(
                  address _aggregator,
                  address _accessController
                )
                  public
                  AggregatorProxy(_aggregator)
                {
                  setController(_accessController);
                }
              
                /**
                 * @notice Allows the owner to update the accessController contract address.
                 * @param _accessController The new address for the accessController contract
                 */
                function setController(address _accessController)
                  public
                  onlyOwner()
                {
                  accessController = AccessControllerInterface(_accessController);
                }
              
                /**
                 * @notice Reads the current answer from aggregator delegated to.
                 * @dev overridden function to add the checkAccess() modifier
                 *
                 * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended latestRoundData
                 * instead which includes better verification information.
                 */
                function latestAnswer()
                  public
                  view
                  override
                  checkAccess()
                  returns (int256)
                {
                  return super.latestAnswer();
                }
              
                /**
                 * @notice get the latest completed round where the answer was updated. This
                 * ID includes the proxy's phase, to make sure round IDs increase even when
                 * switching to a newly deployed aggregator.
                 *
                 * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended latestRoundData
                 * instead which includes better verification information.
                 */
                function latestTimestamp()
                  public
                  view
                  override
                  checkAccess()
                  returns (uint256)
                {
                  return super.latestTimestamp();
                }
              
                /**
                 * @notice get past rounds answers
                 * @param _roundId the answer number to retrieve the answer for
                 * @dev overridden function to add the checkAccess() modifier
                 *
                 * @dev #[deprecated] Use getRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended getRoundData
                 * instead which includes better verification information.
                 */
                function getAnswer(uint256 _roundId)
                  public
                  view
                  override
                  checkAccess()
                  returns (int256)
                {
                  return super.getAnswer(_roundId);
                }
              
                /**
                 * @notice get block timestamp when an answer was last updated
                 * @param _roundId the answer number to retrieve the updated timestamp for
                 * @dev overridden function to add the checkAccess() modifier
                 *
                 * @dev #[deprecated] Use getRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended getRoundData
                 * instead which includes better verification information.
                 */
                function getTimestamp(uint256 _roundId)
                  public
                  view
                  override
                  checkAccess()
                  returns (uint256)
                {
                  return super.getTimestamp(_roundId);
                }
              
                /**
                 * @notice get the latest completed round where the answer was updated
                 * @dev overridden function to add the checkAccess() modifier
                 *
                 * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                 * answer has been reached, it will simply return 0. Either wait to point to
                 * an already answered Aggregator or use the recommended latestRoundData
                 * instead which includes better verification information.
                 */
                function latestRound()
                  public
                  view
                  override
                  checkAccess()
                  returns (uint256)
                {
                  return super.latestRound();
                }
              
                /**
                 * @notice get data about a round. Consumers are encouraged to check
                 * that they're receiving fresh data by inspecting the updatedAt and
                 * answeredInRound return values.
                 * Note that different underlying implementations of AggregatorV3Interface
                 * have slightly different semantics for some of the return values. Consumers
                 * should determine what implementations they expect to receive
                 * data from and validate that they can properly handle return data from all
                 * of them.
                 * @param _roundId the round ID to retrieve the round data for
                 * @return roundId is the round ID from the aggregator for which the data was
                 * retrieved combined with a phase to ensure that round IDs get larger as
                 * time moves forward.
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @dev Note that answer and updatedAt may change between queries.
                 */
                function getRoundData(uint80 _roundId)
                  public
                  view
                  checkAccess()
                  override
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return super.getRoundData(_roundId);
                }
              
                /**
                 * @notice get data about the latest round. Consumers are encouraged to check
                 * that they're receiving fresh data by inspecting the updatedAt and
                 * answeredInRound return values.
                 * Note that different underlying implementations of AggregatorV3Interface
                 * have slightly different semantics for some of the return values. Consumers
                 * should determine what implementations they expect to receive
                 * data from and validate that they can properly handle return data from all
                 * of them.
                 * @return roundId is the round ID from the aggregator for which the data was
                 * retrieved combined with a phase to ensure that round IDs get larger as
                 * time moves forward.
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @dev Note that answer and updatedAt may change between queries.
                 */
                function latestRoundData()
                  public
                  view
                  checkAccess()
                  override
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return super.latestRoundData();
                }
              
                /**
                 * @notice Used if an aggregator contract has been proposed.
                 * @param _roundId the round ID to retrieve the round data for
                 * @return roundId is the round ID for which data was retrieved
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                */
                function proposedGetRoundData(uint80 _roundId)
                  public
                  view
                  checkAccess()
                  hasProposal()
                  override
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return super.proposedGetRoundData(_roundId);
                }
              
                /**
                 * @notice Used if an aggregator contract has been proposed.
                 * @return roundId is the round ID for which data was retrieved
                 * @return answer is the answer for the given round
                 * @return startedAt is the timestamp when the round was started.
                 * (Only some AggregatorV3Interface implementations return meaningful values)
                 * @return updatedAt is the timestamp when the round last was updated (i.e.
                 * answer was last computed)
                 * @return answeredInRound is the round ID of the round in which the answer
                 * was computed.
                */
                function proposedLatestRoundData()
                  public
                  view
                  checkAccess()
                  hasProposal()
                  override
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return super.proposedLatestRoundData();
                }
              
                /**
                 * @dev reverts if the caller does not have access by the accessController
                 * contract or is the contract itself.
                 */
                modifier checkAccess() {
                  AccessControllerInterface ac = accessController;
                  require(address(ac) == address(0) || ac.hasAccess(msg.sender, msg.data), "No access");
                  _;
                }
              }

              File 7 of 7: AccessControlledOCR2Aggregator
              // SPDX-License-Identifier: MIT
              pragma solidity =0.8.19;
              import "./OCR2Aggregator.sol";
              import "./SimpleReadAccessController.sol";
              /**
               * @notice Wrapper of OCR2Aggregator which checks read access on Aggregator-interface methods
               */
              contract AccessControlledOCR2Aggregator is OCR2Aggregator, SimpleReadAccessController {
                constructor(
                  LinkTokenInterface _link,
                  int192 _minAnswer,
                  int192 _maxAnswer,
                  AccessControllerInterface _billingAccessController,
                  AccessControllerInterface _requesterAccessController,
                  uint8 _decimals,
                  string memory description
                )
                  OCR2Aggregator(
                    _link,
                    _minAnswer,
                    _maxAnswer,
                    _billingAccessController,
                    _requesterAccessController,
                    _decimals,
                    description
                  ) {
                  }
                /*
                 * Versioning
                 */
                function typeAndVersion()
                  external
                  override
                  pure
                  virtual
                  returns (string memory)
                {
                  return "AccessControlledOCR2Aggregator 1.0.0";
                }
                /*
                 * v2 Aggregator interface
                 */
                /// @inheritdoc OCR2Aggregator
                function latestAnswer()
                  public
                  override
                  view
                  checkAccess()
                  returns (int256)
                {
                  return super.latestAnswer();
                }
                /// @inheritdoc OCR2Aggregator
                function latestTimestamp()
                  public
                  override
                  view
                  checkAccess()
                  returns (uint256)
                {
                  return super.latestTimestamp();
                }
                /// @inheritdoc OCR2Aggregator
                function latestRound()
                  public
                  override
                  view
                  checkAccess()
                  returns (uint256)
                {
                  return super.latestRound();
                }
                /// @inheritdoc OCR2Aggregator
                function getAnswer(uint256 _roundId)
                  public
                  override
                  view
                  checkAccess()
                  returns (int256)
                {
                  return super.getAnswer(_roundId);
                }
                /// @inheritdoc OCR2Aggregator
                function getTimestamp(uint256 _roundId)
                  public
                  override
                  view
                  checkAccess()
                  returns (uint256)
                {
                  return super.getTimestamp(_roundId);
                }
                /*
                 * v3 Aggregator interface
                 */
                /// @inheritdoc OCR2Aggregator
                function description()
                  public
                  override
                  view
                  checkAccess()
                  returns (string memory)
                {
                  return super.description();
                }
                /// @inheritdoc OCR2Aggregator
                function getRoundData(uint80 _roundId)
                  public
                  override
                  view
                  checkAccess()
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return super.getRoundData(_roundId);
                }
                /// @inheritdoc OCR2Aggregator
                function latestRoundData()
                  public
                  override
                  view
                  checkAccess()
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  return super.latestRoundData();
                }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./ConfirmedOwnerWithProposal.sol";
              /**
               * @title The ConfirmedOwner contract
               * @notice A contract with helpers for basic contract ownership.
               */
              contract ConfirmedOwner is ConfirmedOwnerWithProposal {
                constructor(
                  address newOwner
                )
                  ConfirmedOwnerWithProposal(
                    newOwner,
                    address(0)
                  )
                {
                }
              }// SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./interfaces/OwnableInterface.sol";
              /**
               * @title The ConfirmedOwner contract
               * @notice A contract with helpers for basic contract ownership.
               */
              contract ConfirmedOwnerWithProposal is OwnableInterface {
                address private s_owner;
                address private s_pendingOwner;
                event OwnershipTransferRequested(
                  address indexed from,
                  address indexed to
                );
                event OwnershipTransferred(
                  address indexed from,
                  address indexed to
                );
                constructor(
                  address newOwner,
                  address pendingOwner
                ) {
                  require(newOwner != address(0), "Cannot set owner to zero");
                  s_owner = newOwner;
                  if (pendingOwner != address(0)) {
                    _transferOwnership(pendingOwner);
                  }
                }
                /**
                 * @notice Allows an owner to begin transferring ownership to a new address,
                 * pending.
                 */
                function transferOwnership(
                  address to
                )
                  public
                  override
                  onlyOwner()
                {
                  _transferOwnership(to);
                }
                /**
                 * @notice Allows an ownership transfer to be completed by the recipient.
                 */
                function acceptOwnership()
                  external
                  override
                {
                  require(msg.sender == s_pendingOwner, "Must be proposed owner");
                  address oldOwner = s_owner;
                  s_owner = msg.sender;
                  s_pendingOwner = address(0);
                  emit OwnershipTransferred(oldOwner, msg.sender);
                }
                /**
                 * @notice Get the current owner
                 */
                function owner()
                  public
                  view
                  override
                  returns (
                    address
                  )
                {
                  return s_owner;
                }
                /**
                 * @notice validate, transfer ownership, and emit relevant events
                 */
                function _transferOwnership(
                  address to
                )
                  private
                {
                  require(to != msg.sender, "Cannot transfer to self");
                  s_pendingOwner = to;
                  emit OwnershipTransferRequested(s_owner, to);
                }
                /**
                 * @notice validate access
                 */
                function _validateOwnership()
                  internal
                  view
                {
                  require(msg.sender == s_owner, "Only callable by owner");
                }
                /**
                 * @notice Reverts if called by anyone other than the contract owner.
                 */
                modifier onlyOwner() {
                  _validateOwnership();
                  _;
                }
              }// SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./interfaces/TypeAndVersionInterface.sol";
              abstract contract OCR2Abstract is TypeAndVersionInterface {
                // Maximum number of oracles the offchain reporting protocol is designed for
                uint256 constant internal maxNumOracles = 31;
                /**
                 * @notice triggers a new run of the offchain reporting protocol
                 * @param previousConfigBlockNumber block in which the previous config was set, to simplify historic analysis
                 * @param configDigest configDigest of this configuration
                 * @param configCount ordinal number of this config setting among all config settings over the life of this contract
                 * @param signers ith element is address ith oracle uses to sign a report
                 * @param transmitters ith element is address ith oracle uses to transmit a report via the transmit method
                 * @param f maximum number of faulty/dishonest oracles the protocol can tolerate while still working correctly
                 * @param onchainConfig serialized configuration used by the contract (and possibly oracles)
                 * @param offchainConfigVersion version of the serialization format used for "offchainConfig" parameter
                 * @param offchainConfig serialized configuration used by the oracles exclusively and only passed through the contract
                 */
                event ConfigSet(
                  uint32 previousConfigBlockNumber,
                  bytes32 configDigest,
                  uint64 configCount,
                  address[] signers,
                  address[] transmitters,
                  uint8 f,
                  bytes onchainConfig,
                  uint64 offchainConfigVersion,
                  bytes offchainConfig
                );
                /**
                 * @notice sets offchain reporting protocol configuration incl. participating oracles
                 * @param signers addresses with which oracles sign the reports
                 * @param transmitters addresses oracles use to transmit the reports
                 * @param f number of faulty oracles the system can tolerate
                 * @param onchainConfig serialized configuration used by the contract (and possibly oracles)
                 * @param offchainConfigVersion version number for offchainEncoding schema
                 * @param offchainConfig serialized configuration used by the oracles exclusively and only passed through the contract
                 */
                function setConfig(
                  address[] memory signers,
                  address[] memory transmitters,
                  uint8 f,
                  bytes memory onchainConfig,
                  uint64 offchainConfigVersion,
                  bytes memory offchainConfig
                )
                  external
                  virtual;
                /**
                 * @notice information about current offchain reporting protocol configuration
                 * @return configCount ordinal number of current config, out of all configs applied to this contract so far
                 * @return blockNumber block at which this config was set
                 * @return configDigest domain-separation tag for current config (see _configDigestFromConfigData)
                 */
                function latestConfigDetails()
                  external
                  view
                  virtual
                  returns (
                    uint32 configCount,
                    uint32 blockNumber,
                    bytes32 configDigest
                  );
                function _configDigestFromConfigData(
                  uint256 chainId,
                  address contractAddress,
                  uint64 configCount,
                  address[] memory signers,
                  address[] memory transmitters,
                  uint8 f,
                  bytes memory onchainConfig,
                  uint64 offchainConfigVersion,
                  bytes memory offchainConfig
                )
                  internal
                  pure
                  returns (bytes32)
                {
                  uint256 h = uint256(keccak256(abi.encode(chainId, contractAddress, configCount,
                    signers, transmitters, f, onchainConfig, offchainConfigVersion, offchainConfig
                  )));
                  uint256 prefixMask = type(uint256).max << (256-16); // 0xFFFF00..00
                  uint256 prefix = 0x0001 << (256-16); // 0x000100..00
                  return bytes32((prefix & prefixMask) | (h & ~prefixMask));
                }
                /**
                * @notice optionally emitted to indicate the latest configDigest and epoch for
                   which a report was successfully transmitted. Alternatively, the contract may
                   use latestConfigDigestAndEpoch with scanLogs set to false.
                */
                event Transmitted(
                  bytes32 configDigest,
                  uint32 epoch
                );
                /**
                 * @notice optionally returns the latest configDigest and epoch for which a
                   report was successfully transmitted. Alternatively, the contract may return
                   scanLogs set to true and use Transmitted events to provide this information
                   to offchain watchers.
                 * @return scanLogs indicates whether to rely on the configDigest and epoch
                   returned or whether to scan logs for the Transmitted event instead.
                 * @return configDigest
                 * @return epoch
                 */
                function latestConfigDigestAndEpoch()
                  external
                  view
                  virtual
                  returns(
                    bool scanLogs,
                    bytes32 configDigest,
                    uint32 epoch
                  );
                /**
                 * @notice transmit is called to post a new report to the contract
                 * @param reportContext serialized report context containing configDigest, epoch, round, extraHash
                 * @param report serialized report, which the signatures are signing
                 * @param rs ith element is the R components of the ith signature on report. Must have at most maxNumOracles entries
                 * @param ss ith element is the S components of the ith signature on report. Must have at most maxNumOracles entries
                 * @param rawVs ith element is the the V component of the ith signature
                 */
                function transmit(
                  // NOTE: If these parameters are changed, expectedMsgDataLength and/or
                  // TRANSMIT_MSGDATA_CONSTANT_LENGTH_COMPONENT need to be changed accordingly
                  bytes32[3] calldata reportContext,
                  bytes calldata report,
                  bytes32[] calldata rs, bytes32[] calldata ss, bytes32 rawVs // signatures
                )
                  external
                  virtual;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity =0.8.19;
              import "./interfaces/AccessControllerInterface.sol";
              import "./interfaces/AggregatorV2V3Interface.sol";
              import "./interfaces/AggregatorValidatorInterface.sol";
              import "./interfaces/LinkTokenInterface.sol";
              import "./interfaces/TypeAndVersionInterface.sol";
              import "./OCR2Abstract.sol";
              import "./OwnerIsCreator.sol";
              /**
               * @notice OCR2Aggregator for numerical data with billing support.
               * @dev
               * If you read or change this, be sure to read or adjust the comments. They
               * track the units of the values under consideration, and are crucial to
               * the readability of the operations it specifies.
               * @notice
               * Billing Trust Model:
               * Nothing in this contract prevents a billing admin from setting insane
               * values for the billing parameters in setBilling. Oracles
               * participating in this contract should regularly check that the
               * parameters make sense. Similarly, the outstanding obligations of this
               * contract to the oracles can exceed the funds held by the contract.
               * Oracles participating in this contract should regularly check that it
               * holds sufficient funds and stop interacting with it if funding runs
               * out.
               * This still leaves oracles with some risk due to TOCTOU issues.
               * However, since the sums involved are pretty small (Ethereum
               * transactions aren't that expensive in the end) and an oracle would
               * likely stop participating in a contract it repeatedly lost money on,
               * this risk is deemed acceptable. Oracles should also regularly
               * withdraw any funds in the contract to prevent issues where the
               * contract becomes underfunded at a later time, and different oracles
               * are competing for the left-over funds.
               * Finally, note that any change to the set of oracles or to the billing
               * parameters will trigger payout of all oracles first (using the old
               * parameters), a billing admin cannot take away funds that are already
               * marked for payment.
               */
              contract OCR2Aggregator is OCR2Abstract, OwnerIsCreator, AggregatorV2V3Interface {
                // This contract is divided into sections. Each section defines a set of
                // variables, events, and functions that belong together.
                /***************************************************************************
                 * Section: Variables used in multiple other sections
                 **************************************************************************/
                struct Transmitter {
                  bool active;
                  // Index of oracle in s_signersList/s_transmittersList
                  uint8 index;
                  // juels-denominated payment for transmitters, covering gas costs incurred
                  // by the transmitter plus additional rewards. The entire LINK supply (1e9
                  // LINK = 1e27 Juels) will always fit into a uint96.
                  uint96 paymentJuels;
                }
                mapping (address /* transmitter address */ => Transmitter) internal s_transmitters;
                struct Signer {
                  bool active;
                  // Index of oracle in s_signersList/s_transmittersList
                  uint8 index;
                }
                mapping (address /* signer address */ => Signer) internal s_signers;
                // s_signersList contains the signing address of each oracle
                address[] internal s_signersList;
                // s_transmittersList contains the transmission address of each oracle,
                // i.e. the address the oracle actually sends transactions to the contract from
                address[] internal s_transmittersList;
                // We assume that all oracles contribute observations to all rounds. this
                // variable tracks (per-oracle) from what round an oracle should be rewarded,
                // i.e. the oracle gets (latestAggregatorRoundId -
                // rewardFromAggregatorRoundId) * reward
                uint32[maxNumOracles] internal s_rewardFromAggregatorRoundId;
                bytes32 s_latestConfigDigest;
                // Storing these fields used on the hot path in a HotVars variable reduces the
                // retrieval of all of them to a single SLOAD.
                struct HotVars {
                  // maximum number of faulty oracles
                  uint8 f;
                  // epoch and round from OCR protocol.
                  // 32 most sig bits for epoch, 8 least sig bits for round
                  uint40 latestEpochAndRound;
                  // Chainlink Aggregators expose a roundId to consumers. The offchain reporting
                  // protocol does not use this id anywhere. We increment it whenever a new
                  // transmission is made to provide callers with contiguous ids for successive
                  // reports.
                  uint32 latestAggregatorRoundId;
                  // Highest compensated gas price, in gwei uints
                  uint32 maximumGasPriceGwei;
                  // If gas price is less (in gwei units), transmitter gets half the savings
                  uint32 reasonableGasPriceGwei;
                  // Fixed LINK reward for each observer
                  uint32 observationPaymentGjuels;
                  // Fixed reward for transmitter
                  uint32 transmissionPaymentGjuels;
                  // Overhead incurred by accounting logic
                  uint24 accountingGas;
                }
                HotVars internal s_hotVars;
                // Transmission records the median answer from the transmit transaction at
                // time timestamp
                struct Transmission {
                  int192 answer; // 192 bits ought to be enough for anyone
                  uint32 observationsTimestamp; // when were observations made offchain
                  uint32 transmissionTimestamp; // when was report received onchain
                }
                mapping(uint32 /* aggregator round ID */ => Transmission) internal s_transmissions;
                // Lowest answer the system is allowed to report in response to transmissions
                int192 immutable public minAnswer;
                // Highest answer the system is allowed to report in response to transmissions
                int192 immutable public maxAnswer;
                /***************************************************************************
                 * Section: Constructor
                 **************************************************************************/
                /**
                 * @param link address of the LINK contract
                 * @param minAnswer_ lowest answer the median of a report is allowed to be
                 * @param maxAnswer_ highest answer the median of a report is allowed to be
                 * @param requesterAccessController access controller for requesting new rounds
                 * @param decimals_ answers are stored in fixed-point format, with this many digits of precision
                 * @param description_ short human-readable description of observable this contract's answers pertain to
                 */
                constructor(
                  LinkTokenInterface link,
                  int192 minAnswer_,
                  int192 maxAnswer_,
                  AccessControllerInterface billingAccessController,
                  AccessControllerInterface requesterAccessController,
                  uint8 decimals_,
                  string memory description_
                ) {
                  s_linkToken = link;
                  emit LinkTokenSet(LinkTokenInterface(address(0)), link);
                  _setBillingAccessController(billingAccessController);
                  decimals = decimals_;
                  s_description = description_;
                  setRequesterAccessController(requesterAccessController);
                  setValidatorConfig(AggregatorValidatorInterface(address(0x0)), 0);
                  minAnswer = minAnswer_;
                  maxAnswer = maxAnswer_;
                }
                /***************************************************************************
                 * Section: OCR2Abstract Configuration
                 **************************************************************************/
                // incremented each time a new config is posted. This count is incorporated
                // into the config digest to prevent replay attacks.
                uint32 internal s_configCount;
                // makes it easier for offchain systems to extract config from logs
                uint32 internal s_latestConfigBlockNumber;
                // left as a function so this check can be disabled in derived contracts
                function _requirePositiveF (
                  uint256 f
                )
                  internal
                  pure
                  virtual
                {
                  require(0 < f, "f must be positive");
                }
                struct SetConfigArgs {
                  address[] signers;
                  address[] transmitters;
                  uint8 f;
                  bytes onchainConfig;
                  uint64 offchainConfigVersion;
                  bytes offchainConfig;
                }
                /// @inheritdoc OCR2Abstract
                function setConfig(
                  address[] memory signers,
                  address[] memory transmitters,
                  uint8 f,
                  bytes memory onchainConfig,
                  uint64 offchainConfigVersion,
                  bytes memory offchainConfig
                )
                  external
                  override
                  onlyOwner()
                {
                  require(signers.length <= maxNumOracles, "too many oracles");
                  require(signers.length == transmitters.length, "oracle length mismatch");
                  require(3*f < signers.length, "faulty-oracle f too high");
                  _requirePositiveF(f);
                  require(keccak256(onchainConfig) == keccak256(abi.encodePacked(uint8(1) /*version*/, minAnswer, maxAnswer)), "invalid onchainConfig");
                  SetConfigArgs memory args = SetConfigArgs({
                    signers: signers,
                    transmitters: transmitters,
                    f: f,
                    onchainConfig: onchainConfig,
                    offchainConfigVersion: offchainConfigVersion,
                    offchainConfig: offchainConfig
                  });
                  s_hotVars.latestEpochAndRound = 0;
                  _payOracles();
                  // remove any old signer/transmitter addresses
                  uint256 oldLength = s_signersList.length;
                  for (uint256 i = 0; i < oldLength; i++) {
                    address signer = s_signersList[i];
                    address transmitter = s_transmittersList[i];
                    delete s_signers[signer];
                    delete s_transmitters[transmitter];
                  }
                  delete s_signersList;
                  delete s_transmittersList;
                  // add new signer/transmitter addresses
                  for (uint i = 0; i < args.signers.length; i++) {
                    require(
                      !s_signers[args.signers[i]].active,
                      "repeated signer address"
                    );
                    s_signers[args.signers[i]] = Signer({
                      active: true,
                      index: uint8(i)
                    });
                    require(
                      !s_transmitters[args.transmitters[i]].active,
                      "repeated transmitter address"
                    );
                    s_transmitters[args.transmitters[i]] = Transmitter({
                      active: true,
                      index: uint8(i),
                      paymentJuels: 0
                    });
                  }
                  s_signersList = args.signers;
                  s_transmittersList = args.transmitters;
                  s_hotVars.f = args.f;
                  uint32 previousConfigBlockNumber = s_latestConfigBlockNumber;
                  s_latestConfigBlockNumber = uint32(block.number);
                  s_configCount += 1;
                  s_latestConfigDigest = _configDigestFromConfigData(
                    block.chainid,
                    address(this),
                    s_configCount,
                    args.signers,
                    args.transmitters,
                    args.f,
                    args.onchainConfig,
                    args.offchainConfigVersion,
                    args.offchainConfig
                  );
                  emit ConfigSet(
                    previousConfigBlockNumber,
                    s_latestConfigDigest,
                    s_configCount,
                    args.signers,
                    args.transmitters,
                    args.f,
                    args.onchainConfig,
                    args.offchainConfigVersion,
                    args.offchainConfig
                  );
                  uint32 latestAggregatorRoundId = s_hotVars.latestAggregatorRoundId;
                  for (uint256 i = 0; i < args.signers.length; i++) {
                    s_rewardFromAggregatorRoundId[i] = latestAggregatorRoundId;
                  }
                }
                /// @inheritdoc OCR2Abstract
                function latestConfigDetails()
                  external
                  override
                  view
                  returns (
                    uint32 configCount,
                    uint32 blockNumber,
                    bytes32 configDigest
                  )
                {
                  return (s_configCount, s_latestConfigBlockNumber, s_latestConfigDigest);
                }
                /**
                 * @return list of addresses permitted to transmit reports to this contract
                 * @dev The list will match the order used to specify the transmitter during setConfig
                 */
                function getTransmitters()
                  external
                  view
                  returns(address[] memory)
                {
                  return s_transmittersList;
                }
                /***************************************************************************
                 * Section: Onchain Validation
                 **************************************************************************/
                // Configuration for validator
                struct ValidatorConfig {
                  AggregatorValidatorInterface validator;
                  uint32 gasLimit;
                }
                ValidatorConfig private s_validatorConfig;
                /**
                 * @notice indicates that the validator configuration has been set
                 * @param previousValidator previous validator contract
                 * @param previousGasLimit previous gas limit for validate calls
                 * @param currentValidator current validator contract
                 * @param currentGasLimit current gas limit for validate calls
                 */
                event ValidatorConfigSet(
                  AggregatorValidatorInterface indexed previousValidator,
                  uint32 previousGasLimit,
                  AggregatorValidatorInterface indexed currentValidator,
                  uint32 currentGasLimit
                );
                /**
                 * @notice validator configuration
                 * @return validator validator contract
                 * @return gasLimit gas limit for validate calls
                 */
                function getValidatorConfig()
                  external
                  view
                  returns (AggregatorValidatorInterface validator, uint32 gasLimit)
                {
                  ValidatorConfig memory vc = s_validatorConfig;
                  return (vc.validator, vc.gasLimit);
                }
                /**
                 * @notice sets validator configuration
                 * @dev set newValidator to 0x0 to disable validate calls
                 * @param newValidator address of the new validator contract
                 * @param newGasLimit new gas limit for validate calls
                 */
                function setValidatorConfig(
                  AggregatorValidatorInterface newValidator,
                  uint32 newGasLimit
                )
                  public
                  onlyOwner()
                {
                  ValidatorConfig memory previous = s_validatorConfig;
                  if (previous.validator != newValidator || previous.gasLimit != newGasLimit) {
                    s_validatorConfig = ValidatorConfig({
                      validator: newValidator,
                      gasLimit: newGasLimit
                    });
                    emit ValidatorConfigSet(previous.validator, previous.gasLimit, newValidator, newGasLimit);
                  }
                }
                function _validateAnswer(
                  uint32 aggregatorRoundId,
                  int256 answer
                )
                  private
                {
                  ValidatorConfig memory vc = s_validatorConfig;
                  if (address(vc.validator) == address(0)) {
                    return;
                  }
                  uint32 prevAggregatorRoundId = aggregatorRoundId - 1;
                  int256 prevAggregatorRoundAnswer = s_transmissions[prevAggregatorRoundId].answer;
                  require(
                    _callWithExactGasEvenIfTargetIsNoContract(
                      vc.gasLimit,
                      address(vc.validator),
                      abi.encodeWithSignature(
                        "validate(uint256,int256,uint256,int256)",
                        uint256(prevAggregatorRoundId),
                        prevAggregatorRoundAnswer,
                        uint256(aggregatorRoundId),
                        answer
                      )
                    ),
                    "insufficient gas"
                  );
                }
                uint256 private constant CALL_WITH_EXACT_GAS_CUSHION = 5_000;
                /**
                 * @dev calls target address with exactly gasAmount gas and data as calldata
                 * or reverts if at least gasAmount gas is not available.
                 */
                function _callWithExactGasEvenIfTargetIsNoContract(
                  uint256 gasAmount,
                  address target,
                  bytes memory data
                )
                  private
                  returns (bool sufficientGas)
                {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                    let g := gas()
                    // Compute g -= CALL_WITH_EXACT_GAS_CUSHION and check for underflow. We
                    // need the cushion since the logic following the above call to gas also
                    // costs gas which we cannot account for exactly. So cushion is a
                    // conservative upper bound for the cost of this logic.
                    if iszero(lt(g, CALL_WITH_EXACT_GAS_CUSHION)) {
                      g := sub(g, CALL_WITH_EXACT_GAS_CUSHION)
                      // If g - g//64 <= gasAmount, we don't have enough gas. (We subtract g//64
                      // because of EIP-150.)
                      if gt(sub(g, div(g, 64)), gasAmount) {
                        // Call and ignore success/return data. Note that we did not check
                        // whether a contract actually exists at the target address.
                        pop(call(gasAmount, target, 0, add(data, 0x20), mload(data), 0, 0))
                        sufficientGas := true
                      }
                    }
                  }
                }
                /***************************************************************************
                 * Section: RequestNewRound
                 **************************************************************************/
                AccessControllerInterface internal s_requesterAccessController;
                /**
                 * @notice emitted when a new requester access controller contract is set
                 * @param old the address prior to the current setting
                 * @param current the address of the new access controller contract
                 */
                event RequesterAccessControllerSet(AccessControllerInterface old, AccessControllerInterface current);
                /**
                 * @notice emitted to immediately request a new round
                 * @param requester the address of the requester
                 * @param configDigest the latest transmission's configDigest
                 * @param epoch the latest transmission's epoch
                 * @param round the latest transmission's round
                 */
                event RoundRequested(address indexed requester, bytes32 configDigest, uint32 epoch, uint8 round);
                /**
                 * @notice address of the requester access controller contract
                 * @return requester access controller address
                 */
                function getRequesterAccessController()
                  external
                  view
                  returns (AccessControllerInterface)
                {
                  return s_requesterAccessController;
                }
                /**
                 * @notice sets the requester access controller
                 * @param requesterAccessController designates the address of the new requester access controller
                 */
                function setRequesterAccessController(AccessControllerInterface requesterAccessController)
                  public
                  onlyOwner()
                {
                  AccessControllerInterface oldController = s_requesterAccessController;
                  if (requesterAccessController != oldController) {
                    s_requesterAccessController = AccessControllerInterface(requesterAccessController);
                    emit RequesterAccessControllerSet(oldController, requesterAccessController);
                  }
                }
                /**
                 * @notice immediately requests a new round
                 * @return the aggregatorRoundId of the next round. Note: The report for this round may have been
                 * transmitted (but not yet mined) *before* requestNewRound() was even called. There is *no*
                 * guarantee of causality between the request and the report at aggregatorRoundId.
                 */
                function requestNewRound() external returns (uint80) {
                  require(msg.sender == owner() || s_requesterAccessController.hasAccess(msg.sender, msg.data),
                    "Only owner&requester can call");
                  uint40 latestEpochAndRound = s_hotVars.latestEpochAndRound;
                  uint32 latestAggregatorRoundId = s_hotVars.latestAggregatorRoundId;
                  emit RoundRequested(
                    msg.sender,
                    s_latestConfigDigest,
                    uint32(latestEpochAndRound >> 8),
                    uint8(latestEpochAndRound)
                  );
                  return latestAggregatorRoundId + 1;
                }
                /***************************************************************************
                 * Section: Transmission
                 **************************************************************************/
                /**
                 * @notice indicates that a new report was transmitted
                 * @param aggregatorRoundId the round to which this report was assigned
                 * @param answer median of the observations attached to this report
                 * @param transmitter address from which the report was transmitted
                 * @param observationsTimestamp when were observations made offchain
                 * @param observations observations transmitted with this report
                 * @param observers i-th element is the oracle id of the oracle that made the i-th observation
                 * @param juelsPerFeeCoin exchange rate between feeCoin (e.g. ETH on Ethereum) and LINK, denominated in juels
                 * @param configDigest configDigest of transmission
                 * @param epochAndRound least-significant byte is the OCR protocol round number, the other bytes give the big-endian OCR protocol epoch number
                 */
                event NewTransmission(
                  uint32 indexed aggregatorRoundId,
                  int192 answer,
                  address transmitter,
                  uint32 observationsTimestamp,
                  int192[] observations,
                  bytes observers,
                  int192 juelsPerFeeCoin,
                  bytes32 configDigest,
                  uint40 epochAndRound
                );
                // Used to relieve stack pressure in transmit
                struct Report {
                  uint32 observationsTimestamp;
                  bytes observers; // ith element is the index of the ith observer
                  int192[] observations; // ith element is the ith observation
                  int192 juelsPerFeeCoin;
                }
                // _decodeReport decodes a serialized report into a Report struct
                function _decodeReport(bytes memory rawReport)
                  internal
                  pure
                  returns (
                    Report memory
                  )
                {
                  uint32 observationsTimestamp;
                  bytes32 rawObservers;
                  int192[] memory observations;
                  int192 juelsPerFeeCoin;
                  (observationsTimestamp, rawObservers, observations, juelsPerFeeCoin) = abi.decode(rawReport, (uint32, bytes32, int192[], int192));
                  _requireExpectedReportLength(rawReport, observations);
                  uint256 numObservations = observations.length;
                  bytes memory observers = abi.encodePacked(rawObservers);
                  assembly {
                    // we truncate observers from length 32 to the number of observations
                    mstore(observers, numObservations)
                  }
                  return Report({
                    observationsTimestamp: observationsTimestamp,
                    observers: observers,
                    observations: observations,
                    juelsPerFeeCoin: juelsPerFeeCoin
                  });
                }
                // The constant-length components of the msg.data sent to transmit.
                // See the "If we wanted to call sam" example on for example reasoning
                // https://solidity.readthedocs.io/en/v0.7.2/abi-spec.html
                uint256 private constant TRANSMIT_MSGDATA_CONSTANT_LENGTH_COMPONENT =
                  4 + // function selector
                  32 * 3 + // 3 words containing reportContext
                  32 + // word containing start location of abiencoded report value
                  32 + // word containing start location of abiencoded rs value
                  32 + // word containing start location of abiencoded ss value
                  32 + // rawVs value
                  32 + // word containing length of report
                  32 + // word containing length rs
                  32 + // word containing length of ss
                  0; // placeholder
                // Make sure the calldata length matches the inputs. Otherwise, the
                // transmitter could append an arbitrarily long (up to gas-block limit)
                // string of 0 bytes, which we would reimburse at a rate of 16 gas/byte, but
                // which would only cost the transmitter 4 gas/byte.
                function _requireExpectedMsgDataLength(
                  bytes calldata report,
                  bytes32[] calldata rs,
                  bytes32[] calldata ss
                )
                  private
                  pure
                {
                  // calldata will never be big enough to make this overflow
                  uint256 expected = TRANSMIT_MSGDATA_CONSTANT_LENGTH_COMPONENT +
                    report.length + // one byte per entry in report
                    rs.length * 32 + // 32 bytes per entry in rs
                    ss.length * 32 + // 32 bytes per entry in ss
                    0; // placeholder
                  require(msg.data.length == expected, "calldata length mismatch");
                }
                /// @inheritdoc OCR2Abstract
                function transmit(
                  // reportContext consists of:
                  // reportContext[0]: ConfigDigest
                  // reportContext[1]: 27 byte padding, 4-byte epoch and 1-byte round
                  // reportContext[2]: ExtraHash
                  bytes32[3] calldata reportContext,
                  bytes calldata report,
                  // ECDSA signatures
                  bytes32[] calldata rs,
                  bytes32[] calldata ss,
                  bytes32 rawVs
                )
                  external
                  override
                {
                  // NOTE: If the arguments to this function are changed, _requireExpectedMsgDataLength and/or
                  // TRANSMIT_MSGDATA_CONSTANT_LENGTH_COMPONENT need to be changed accordingly
                  uint256 initialGas = gasleft(); // This line must come first
                  HotVars memory hotVars = s_hotVars;
                  uint40 epochAndRound = uint40(uint256(reportContext[1]));
                  require(hotVars.latestEpochAndRound < epochAndRound, "stale report");
                  require(s_transmitters[msg.sender].active, "unauthorized transmitter");
                  require(s_latestConfigDigest == reportContext[0], "configDigest mismatch");
                  _requireExpectedMsgDataLength(report, rs, ss);
                  require(rs.length == hotVars.f + 1, "wrong number of signatures");
                  require(rs.length == ss.length, "signatures out of registration");
                  // Verify signatures attached to report
                  {
                    bytes32 h = keccak256(abi.encode(keccak256(report), reportContext));
                    // i-th byte counts number of sigs made by i-th signer
                    uint256 signedCount = 0;
                    Signer memory signer;
                    for (uint i = 0; i < rs.length; i++) {
                      address signerAddress = ecrecover(h, uint8(rawVs[i])+27, rs[i], ss[i]);
                      signer = s_signers[signerAddress];
                      require(signer.active, "signature error");
                      unchecked{
                        signedCount += 1 << (8 * signer.index);
                      }
                    }
                    // The first byte of the mask can be 0, because we only ever have 31 oracles
                    require(signedCount & 0x0001010101010101010101010101010101010101010101010101010101010101 == signedCount, "duplicate signer");
                  }
                  int192 juelsPerFeeCoin = _report(hotVars, reportContext[0], epochAndRound, report);
                  _payTransmitter(hotVars, juelsPerFeeCoin, uint32(initialGas), msg.sender);
                }
                /**
                 * @notice details about the most recent report
                 * @return configDigest domain separation tag for the latest report
                 * @return epoch epoch in which the latest report was generated
                 * @return round OCR round in which the latest report was generated
                 * @return latestAnswer_ median value from latest report
                 * @return latestTimestamp_ when the latest report was transmitted
                 */
                function latestTransmissionDetails()
                  external
                  view
                  returns (
                    bytes32 configDigest,
                    uint32 epoch,
                    uint8 round,
                    int192 latestAnswer_,
                    uint64 latestTimestamp_
                  )
                {
                  require(msg.sender == tx.origin, "Only callable by EOA");
                  return (
                    s_latestConfigDigest,
                    uint32(s_hotVars.latestEpochAndRound >> 8),
                    uint8(s_hotVars.latestEpochAndRound),
                    s_transmissions[s_hotVars.latestAggregatorRoundId].answer,
                    s_transmissions[s_hotVars.latestAggregatorRoundId].transmissionTimestamp
                  );
                }
                /// @inheritdoc OCR2Abstract
                function latestConfigDigestAndEpoch()
                  external
                  override
                  view
                  virtual
                  returns(
                    bool scanLogs,
                    bytes32 configDigest,
                    uint32 epoch
                  )
                {
                  return (false, s_latestConfigDigest, uint32(s_hotVars.latestEpochAndRound >> 8));
                }
                function _requireExpectedReportLength(
                  bytes memory report,
                  int192[] memory observations
                )
                  private
                  pure
                {
                  uint256 expected =
                    32 + // observationsTimestamp
                    32 + // rawObservers
                    32 + // observations offset
                    32 + // juelsPerFeeCoin
                    32 + // observations length
                    32 * observations.length + // observations payload
                    0;
                  require(report.length == expected, "report length mismatch");
                }
                function _report(
                  HotVars memory hotVars,
                  bytes32 configDigest,
                  uint40 epochAndRound,
                  bytes memory rawReport
                )
                  internal
                  returns (int192 juelsPerFeeCoin)
                {
                  Report memory report = _decodeReport(rawReport);
                  require(report.observations.length <= maxNumOracles, "num observations out of bounds");
                  // Offchain logic ensures that a quorum of oracles is operating on a matching set of at least
                  // 2f+1 observations. By assumption, up to f of those can be faulty, which includes being
                  // malformed. Conversely, more than f observations have to be well-formed and sent on chain.
                  require(hotVars.f < report.observations.length, "too few values to trust median");
                  hotVars.latestEpochAndRound = epochAndRound;
                  // get median, validate its range, store it in new aggregator round
                  int192 median = report.observations[report.observations.length/2];
                  require(minAnswer <= median && median <= maxAnswer, "median is out of min-max range");
                  hotVars.latestAggregatorRoundId++;
                  s_transmissions[hotVars.latestAggregatorRoundId] =
                    Transmission({
                      answer: median,
                      observationsTimestamp: report.observationsTimestamp,
                      transmissionTimestamp: uint32(block.timestamp)
                    });
                  // persist updates to hotVars
                  s_hotVars = hotVars;
                  emit NewTransmission(
                    hotVars.latestAggregatorRoundId,
                    median,
                    msg.sender,
                    report.observationsTimestamp,
                    report.observations,
                    report.observers,
                    report.juelsPerFeeCoin,
                    configDigest,
                    epochAndRound
                  );
                  // Emit these for backwards compatibility with offchain consumers
                  // that only support legacy events
                  emit NewRound(
                    hotVars.latestAggregatorRoundId,
                    address(0x0), // use zero address since we don't have anybody "starting" the round here
                    report.observationsTimestamp
                  );
                  emit AnswerUpdated(
                    median,
                    hotVars.latestAggregatorRoundId,
                    block.timestamp
                  );
                  _validateAnswer(hotVars.latestAggregatorRoundId, median);
                  return report.juelsPerFeeCoin;
                }
                /***************************************************************************
                 * Section: v2 AggregatorInterface
                 **************************************************************************/
                /**
                 * @notice median from the most recent report
                 */
                function latestAnswer()
                  public
                  override
                  view
                  virtual
                  returns (int256)
                {
                  return s_transmissions[s_hotVars.latestAggregatorRoundId].answer;
                }
                /**
                 * @notice timestamp of block in which last report was transmitted
                 */
                function latestTimestamp()
                  public
                  override
                  view
                  virtual
                  returns (uint256)
                {
                  return s_transmissions[s_hotVars.latestAggregatorRoundId].transmissionTimestamp;
                }
                /**
                 * @notice Aggregator round (NOT OCR round) in which last report was transmitted
                 */
                function latestRound()
                  public
                  override
                  view
                  virtual
                  returns (uint256)
                {
                  return s_hotVars.latestAggregatorRoundId;
                }
                /**
                 * @notice median of report from given aggregator round (NOT OCR round)
                 * @param roundId the aggregator round of the target report
                 */
                function getAnswer(uint256 roundId)
                  public
                  override
                  view
                  virtual
                  returns (int256)
                {
                  if (roundId > 0xFFFFFFFF) { return 0; }
                  return s_transmissions[uint32(roundId)].answer;
                }
                /**
                 * @notice timestamp of block in which report from given aggregator round was transmitted
                 * @param roundId aggregator round (NOT OCR round) of target report
                 */
                function getTimestamp(uint256 roundId)
                  public
                  override
                  view
                  virtual
                  returns (uint256)
                {
                  if (roundId > 0xFFFFFFFF) { return 0; }
                  return s_transmissions[uint32(roundId)].transmissionTimestamp;
                }
                /***************************************************************************
                 * Section: v3 AggregatorInterface
                 **************************************************************************/
                /**
                 * @return answers are stored in fixed-point format, with this many digits of precision
                 */
                uint8 immutable public override decimals;
                /**
                 * @notice aggregator contract version
                 */
                uint256 constant public override version = 6;
                string internal s_description;
                /**
                 * @notice human-readable description of observable this contract is reporting on
                 */
                function description()
                  public
                  override
                  view
                  virtual
                  returns (string memory)
                {
                  return s_description;
                }
                /**
                 * @notice details for the given aggregator round
                 * @param roundId target aggregator round (NOT OCR round). Must fit in uint32
                 * @return roundId_ roundId
                 * @return answer median of report from given roundId
                 * @return startedAt timestamp of when observations were made offchain
                 * @return updatedAt timestamp of block in which report from given roundId was transmitted
                 * @return answeredInRound roundId
                 */
                function getRoundData(uint80 roundId)
                  public
                  override
                  view
                  virtual
                  returns (
                    uint80 roundId_,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  if(roundId > type(uint32).max) { return (0, 0, 0, 0, 0); }
                  Transmission memory transmission = s_transmissions[uint32(roundId)];
                  return (
                    roundId,
                    transmission.answer,
                    transmission.observationsTimestamp,
                    transmission.transmissionTimestamp,
                    roundId
                  );
                }
                /**
                 * @notice aggregator details for the most recently transmitted report
                 * @return roundId aggregator round of latest report (NOT OCR round)
                 * @return answer median of latest report
                 * @return startedAt timestamp of when observations were made offchain
                 * @return updatedAt timestamp of block containing latest report
                 * @return answeredInRound aggregator round of latest report
                 */
                function latestRoundData()
                  public
                  override
                  view
                  virtual
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  )
                {
                  uint32 latestAggregatorRoundId = s_hotVars.latestAggregatorRoundId;
                  Transmission memory transmission = s_transmissions[latestAggregatorRoundId];
                  return (
                    latestAggregatorRoundId,
                    transmission.answer,
                    transmission.observationsTimestamp,
                    transmission.transmissionTimestamp,
                    latestAggregatorRoundId
                  );
                }
                /***************************************************************************
                 * Section: Configurable LINK Token
                 **************************************************************************/
                // We assume that the token contract is correct. This contract is not written
                // to handle misbehaving ERC20 tokens!
                LinkTokenInterface internal s_linkToken;
                /*
                 * @notice emitted when the LINK token contract is set
                 * @param oldLinkToken the address of the old LINK token contract
                 * @param newLinkToken the address of the new LINK token contract
                 */
                event LinkTokenSet(
                  LinkTokenInterface indexed oldLinkToken,
                  LinkTokenInterface indexed newLinkToken
                );
                /**
                 * @notice sets the LINK token contract used for paying oracles
                 * @param linkToken the address of the LINK token contract
                 * @param recipient remaining funds from the previous token contract are transferred
                 * here
                 * @dev this function will return early (without an error) without changing any state
                 * if linkToken equals getLinkToken().
                 * @dev this will trigger a payout so that a malicious owner cannot take from oracles
                 * what is already owed to them.
                 * @dev we assume that the token contract is correct. This contract is not written
                 * to handle misbehaving ERC20 tokens!
                 */
                function setLinkToken(
                  LinkTokenInterface linkToken,
                  address recipient
                ) external
                  onlyOwner()
                {
                  LinkTokenInterface oldLinkToken = s_linkToken;
                  if (linkToken == oldLinkToken) {
                    // No change, nothing to be done
                    return;
                  }
                  // call balanceOf as a sanity check on whether we're talking to a token
                  // contract
                  linkToken.balanceOf(address(this));
                  // we break CEI here, but that's okay because we're dealing with a correct
                  // token contract (by assumption).
                  _payOracles();
                  uint256 remainingBalance = oldLinkToken.balanceOf(address(this));
                  require(oldLinkToken.transfer(recipient, remainingBalance), "transfer remaining funds failed");
                  s_linkToken = linkToken;
                  emit LinkTokenSet(oldLinkToken, linkToken);
                }
                /*
                 * @notice gets the LINK token contract used for paying oracles
                 * @return linkToken the address of the LINK token contract
                 */
                function getLinkToken()
                  external
                  view
                  returns(LinkTokenInterface linkToken)
                {
                  return s_linkToken;
                }
                /***************************************************************************
                 * Section: BillingAccessController Management
                 **************************************************************************/
                // Controls who can change billing parameters. A billingAdmin is not able to
                // affect any OCR protocol settings and therefore cannot tamper with the
                // liveness or integrity of a data feed. However, a billingAdmin can set
                // faulty billing parameters causing oracles to be underpaid, or causing them
                // to be paid so much that further calls to setConfig, setBilling,
                // setLinkToken will always fail due to the contract being underfunded.
                AccessControllerInterface internal s_billingAccessController;
                /**
                 * @notice emitted when a new access-control contract is set
                 * @param old the address prior to the current setting
                 * @param current the address of the new access-control contract
                 */
                event BillingAccessControllerSet(AccessControllerInterface old, AccessControllerInterface current);
                function _setBillingAccessController(AccessControllerInterface billingAccessController)
                  internal
                {
                  AccessControllerInterface oldController = s_billingAccessController;
                  if (billingAccessController != oldController) {
                    s_billingAccessController = billingAccessController;
                    emit BillingAccessControllerSet(
                      oldController,
                      billingAccessController
                    );
                  }
                }
                /**
                 * @notice sets billingAccessController
                 * @param _billingAccessController new billingAccessController contract address
                 * @dev only owner can call this
                 */
                function setBillingAccessController(AccessControllerInterface _billingAccessController)
                  external
                  onlyOwner
                {
                  _setBillingAccessController(_billingAccessController);
                }
                /**
                 * @notice gets billingAccessController
                 * @return address of billingAccessController contract
                 */
                function getBillingAccessController()
                  external
                  view
                  returns (AccessControllerInterface)
                {
                  return s_billingAccessController;
                }
                /***************************************************************************
                 * Section: Billing Configuration
                 **************************************************************************/
                /**
                 * @notice emitted when billing parameters are set
                 * @param maximumGasPriceGwei highest gas price for which transmitter will be compensated
                 * @param reasonableGasPriceGwei transmitter will receive reward for gas prices under this value
                 * @param observationPaymentGjuels reward to oracle for contributing an observation to a successfully transmitted report
                 * @param transmissionPaymentGjuels reward to transmitter of a successful report
                 * @param accountingGas gas overhead incurred by accounting logic
                 */
                event BillingSet(
                  uint32 maximumGasPriceGwei,
                  uint32 reasonableGasPriceGwei,
                  uint32 observationPaymentGjuels,
                  uint32 transmissionPaymentGjuels,
                  uint24 accountingGas
                );
                /**
                 * @notice sets billing parameters
                 * @param maximumGasPriceGwei highest gas price for which transmitter will be compensated
                 * @param reasonableGasPriceGwei transmitter will receive reward for gas prices under this value
                 * @param observationPaymentGjuels reward to oracle for contributing an observation to a successfully transmitted report
                 * @param transmissionPaymentGjuels reward to transmitter of a successful report
                 * @param accountingGas gas overhead incurred by accounting logic
                 * @dev access control provided by billingAccessController
                 */
                function setBilling(
                  uint32 maximumGasPriceGwei,
                  uint32 reasonableGasPriceGwei,
                  uint32 observationPaymentGjuels,
                  uint32 transmissionPaymentGjuels,
                  uint24 accountingGas
                )
                  external
                {
                  AccessControllerInterface access = s_billingAccessController;
                  require(msg.sender == owner() || access.hasAccess(msg.sender, msg.data),
                    "Only owner&billingAdmin can call");
                  _payOracles();
                  s_hotVars.maximumGasPriceGwei = maximumGasPriceGwei;
                  s_hotVars.reasonableGasPriceGwei = reasonableGasPriceGwei;
                  s_hotVars.observationPaymentGjuels = observationPaymentGjuels;
                  s_hotVars.transmissionPaymentGjuels = transmissionPaymentGjuels;
                  s_hotVars.accountingGas = accountingGas;
                  emit BillingSet(maximumGasPriceGwei, reasonableGasPriceGwei,
                    observationPaymentGjuels, transmissionPaymentGjuels, accountingGas);
                }
                /**
                 * @notice gets billing parameters
                 * @param maximumGasPriceGwei highest gas price for which transmitter will be compensated
                 * @param reasonableGasPriceGwei transmitter will receive reward for gas prices under this value
                 * @param observationPaymentGjuels reward to oracle for contributing an observation to a successfully transmitted report
                 * @param transmissionPaymentGjuels reward to transmitter of a successful report
                 * @param accountingGas gas overhead of the accounting logic
                 */
                function getBilling()
                  external
                  view
                  returns (
                    uint32 maximumGasPriceGwei,
                    uint32 reasonableGasPriceGwei,
                    uint32 observationPaymentGjuels,
                    uint32 transmissionPaymentGjuels,
                    uint24 accountingGas
                  )
                {
                  return (
                    s_hotVars.maximumGasPriceGwei,
                    s_hotVars.reasonableGasPriceGwei,
                    s_hotVars.observationPaymentGjuels,
                    s_hotVars.transmissionPaymentGjuels,
                    s_hotVars.accountingGas
                  );
                }
                /***************************************************************************
                 * Section: Payments and Withdrawals
                 **************************************************************************/
                /**
                 * @notice withdraws an oracle's payment from the contract
                 * @param transmitter the transmitter address of the oracle
                 * @dev must be called by oracle's payee address
                 */
                function withdrawPayment(address transmitter)
                  external
                {
                  require(msg.sender == s_payees[transmitter], "Only payee can withdraw");
                  _payOracle(transmitter);
                }
                /**
                 * @notice query an oracle's payment amount, denominated in juels
                 * @param transmitterAddress the transmitter address of the oracle
                 */
                function owedPayment(address transmitterAddress)
                  public
                  view
                  returns (uint256)
                {
                  Transmitter memory transmitter = s_transmitters[transmitterAddress];
                  if (!transmitter.active) { return 0; }
                  // safe from overflow:
                  // s_hotVars.latestAggregatorRoundId - s_rewardFromAggregatorRoundId[transmitter.index] <= 2**32
                  // s_hotVars.observationPaymentGjuels <= 2**32
                  // 1 gwei <= 2**32
                  // hence juelsAmount <= 2**96
                  uint256 juelsAmount =
                    uint256(s_hotVars.latestAggregatorRoundId - s_rewardFromAggregatorRoundId[transmitter.index]) *
                    uint256(s_hotVars.observationPaymentGjuels) *
                    (1 gwei);
                  juelsAmount += transmitter.paymentJuels;
                  return juelsAmount;
                }
                /**
                 * @notice emitted when an oracle has been paid LINK
                 * @param transmitter address from which the oracle sends reports to the transmit method
                 * @param payee address to which the payment is sent
                 * @param amount amount of LINK sent
                 * @param linkToken address of the LINK token contract
                 */
                event OraclePaid(
                  address indexed transmitter,
                  address indexed payee,
                  uint256 amount,
                  LinkTokenInterface indexed linkToken
                );
                // _payOracle pays out transmitter's balance to the corresponding payee, and zeros it out
                function _payOracle(address transmitterAddress)
                  internal
                {
                  Transmitter memory transmitter = s_transmitters[transmitterAddress];
                  if (!transmitter.active) { return; }
                  uint256 juelsAmount = owedPayment(transmitterAddress);
                  if (juelsAmount > 0) {
                    address payee = s_payees[transmitterAddress];
                    // Poses no re-entrancy issues, because LINK.transfer does not yield
                    // control flow.
                    require(s_linkToken.transfer(payee, juelsAmount), "insufficient funds");
                    s_rewardFromAggregatorRoundId[transmitter.index] = s_hotVars.latestAggregatorRoundId;
                    s_transmitters[transmitterAddress].paymentJuels = 0;
                    emit OraclePaid(transmitterAddress, payee, juelsAmount, s_linkToken);
                  }
                }
                // _payOracles pays out all transmitters, and zeros out their balances.
                //
                // It's much more gas-efficient to do this as a single operation, to avoid
                // hitting storage too much.
                function _payOracles()
                  internal
                {
                  unchecked {
                    LinkTokenInterface linkToken = s_linkToken;
                    uint32 latestAggregatorRoundId = s_hotVars.latestAggregatorRoundId;
                    uint32[maxNumOracles] memory rewardFromAggregatorRoundId = s_rewardFromAggregatorRoundId;
                    address[] memory transmitters = s_transmittersList;
                    for (uint transmitteridx = 0; transmitteridx < transmitters.length; transmitteridx++) {
                      uint256 reimbursementAmountJuels = s_transmitters[transmitters[transmitteridx]].paymentJuels;
                      s_transmitters[transmitters[transmitteridx]].paymentJuels = 0;
                      uint256 obsCount = latestAggregatorRoundId - rewardFromAggregatorRoundId[transmitteridx];
                      uint256 juelsAmount =
                        obsCount * uint256(s_hotVars.observationPaymentGjuels) * (1 gwei) + reimbursementAmountJuels;
                      if (juelsAmount > 0) {
                          address payee = s_payees[transmitters[transmitteridx]];
                          // Poses no re-entrancy issues, because LINK.transfer does not yield
                          // control flow.
                          require(linkToken.transfer(payee, juelsAmount), "insufficient funds");
                          rewardFromAggregatorRoundId[transmitteridx] = latestAggregatorRoundId;
                          emit OraclePaid(transmitters[transmitteridx], payee, juelsAmount, linkToken);
                        }
                    }
                    // "Zero" the accounting storage variables
                    s_rewardFromAggregatorRoundId = rewardFromAggregatorRoundId;
                  }
                }
                /**
                 * @notice withdraw any available funds left in the contract, up to amount, after accounting for the funds due to participants in past reports
                 * @param recipient address to send funds to
                 * @param amount maximum amount to withdraw, denominated in LINK-wei.
                 * @dev access control provided by billingAccessController
                 */
                function withdrawFunds(
                  address recipient,
                  uint256 amount
                )
                  external
                {
                  require(msg.sender == owner() || s_billingAccessController.hasAccess(msg.sender, msg.data),
                    "Only owner&billingAdmin can call");
                  uint256 linkDue = _totalLinkDue();
                  uint256 linkBalance = s_linkToken.balanceOf(address(this));
                  require(linkBalance >= linkDue, "insufficient balance");
                  require(s_linkToken.transfer(recipient, _min(linkBalance - linkDue, amount)), "insufficient funds");
                }
                // Total LINK due to participants in past reports (denominated in Juels).
                function _totalLinkDue()
                  internal
                  view
                  returns (uint256 linkDue)
                {
                  // Argument for overflow safety: We do all computations in
                  // uint256s. The inputs to linkDue are:
                  // - the <= 31 observation rewards each of which has less than
                  //   64 bits (32 bits for observationPaymentGjuels, 32 bits
                  //   for wei/gwei conversion). Hence 69 bits are sufficient for this part.
                  // - the <= 31 gas reimbursements, each of which consists of at most 96
                  //   bits. Hence 101 bits are sufficient for this part.
                  // So we never need more than 102 bits.
                  address[] memory transmitters = s_transmittersList;
                  uint256 n = transmitters.length;
                  uint32 latestAggregatorRoundId = s_hotVars.latestAggregatorRoundId;
                  uint32[maxNumOracles] memory rewardFromAggregatorRoundId = s_rewardFromAggregatorRoundId;
                  for (uint i = 0; i < n; i++) {
                    linkDue += latestAggregatorRoundId - rewardFromAggregatorRoundId[i];
                  }
                  // Convert observationPaymentGjuels to uint256, or this overflows!
                  linkDue *= uint256(s_hotVars.observationPaymentGjuels) * (1 gwei);
                  for (uint i = 0; i < n; i++) {
                    linkDue += uint256(s_transmitters[transmitters[i]].paymentJuels);
                  }
                }
                /**
                 * @notice allows oracles to check that sufficient LINK balance is available
                 * @return availableBalance LINK available on this contract, after accounting for outstanding obligations. can become negative
                 */
                function linkAvailableForPayment()
                  external
                  view
                  returns (int256 availableBalance)
                {
                  // there are at most one billion LINK, so this cast is safe
                  int256 balance = int256(s_linkToken.balanceOf(address(this)));
                  // according to the argument in the definition of _totalLinkDue,
                  // _totalLinkDue is never greater than 2**102, so this cast is safe
                  int256 due = int256(_totalLinkDue());
                  // safe from overflow according to above sizes
                  return int256(balance) - int256(due);
                }
                /**
                 * @notice number of observations oracle is due to be reimbursed for
                 * @param transmitterAddress address used by oracle for signing or transmitting reports
                 */
                function oracleObservationCount(address transmitterAddress)
                  external
                  view
                  returns (uint32)
                {
                  Transmitter memory transmitter = s_transmitters[transmitterAddress];
                  if (!transmitter.active) { return 0; }
                  return s_hotVars.latestAggregatorRoundId - s_rewardFromAggregatorRoundId[transmitter.index];
                }
                /***************************************************************************
                 * Section: Transmitter Payment
                 **************************************************************************/
                // Gas price at which the transmitter should be reimbursed, in gwei/gas
                function _reimbursementGasPriceGwei(
                  uint256 txGasPriceGwei,
                  uint256 reasonableGasPriceGwei,
                  uint256 maximumGasPriceGwei
                )
                  internal
                  pure
                  returns (uint256)
                {
                  // this happens on the path for transmissions. we'd rather pay out
                  // a wrong reward than risk a liveness failure due to a revert.
                  unchecked {
                    // Reward the transmitter for choosing an efficient gas price: if they manage
                    // to come in lower than considered reasonable, give them half the savings.
                    uint256 gasPriceGwei = txGasPriceGwei;
                    if (txGasPriceGwei < reasonableGasPriceGwei) {
                      // Give transmitter half the savings for coming in under the reasonable gas price
                      gasPriceGwei += (reasonableGasPriceGwei - txGasPriceGwei) / 2;
                    }
                    // Don't reimburse a gas price higher than maximumGasPriceGwei
                    return _min(gasPriceGwei, maximumGasPriceGwei);
                  }
                }
                // gas reimbursement due the transmitter, in wei
                function _transmitterGasCostWei(
                  uint256 initialGas,
                  uint256 gasPriceGwei,
                  uint256 callDataGas,
                  uint256 accountingGas,
                  uint256 leftGas
                )
                  internal
                  pure
                  returns (uint256)
                {
                  // this happens on the path for transmissions. we'd rather pay out
                  // a wrong reward than risk a liveness failure due to a revert.
                  unchecked {
                    require(initialGas >= leftGas, "leftGas cannot exceed initialGas");
                    uint256 usedGas =
                      initialGas - leftGas + // observed gas usage
                      callDataGas + accountingGas; // estimated gas usage
                    uint256 fullGasCostWei = usedGas * gasPriceGwei * (1 gwei);
                    return fullGasCostWei;
                  }
                }
                function _payTransmitter(
                  HotVars memory hotVars,
                  int192 juelsPerFeeCoin,
                  uint32 initialGas,
                  address transmitter
                )
                  internal
                  virtual
                {
                  // this happens on the path for transmissions. we'd rather pay out
                  // a wrong reward than risk a liveness failure due to a revert.
                  unchecked {
                    // we can't deal with negative juelsPerFeeCoin, better to just not pay
                    if (juelsPerFeeCoin < 0) {
                      return;
                    }
                    // Reimburse transmitter of the report for gas usage
                    uint256 gasPriceGwei = _reimbursementGasPriceGwei(
                      tx.gasprice / (1 gwei), // convert to ETH-gwei units
                      hotVars.reasonableGasPriceGwei,
                      hotVars.maximumGasPriceGwei
                    );
                    // The following is only an upper bound, as it ignores the cheaper cost for
                    // 0 bytes. Safe from overflow, because calldata just isn't that long.
                    uint256 callDataGasCost = 16 * msg.data.length;
                    uint256 gasLeft = gasleft();
                    uint256 gasCostEthWei = _transmitterGasCostWei(
                      uint256(initialGas),
                      gasPriceGwei,
                      callDataGasCost,
                      hotVars.accountingGas,
                      gasLeft
                    );
                    // Even if we assume absurdly large values, this still does not overflow. With
                    // - usedGas <= 1'000'000 gas <= 2**20 gas
                    // - weiPerGas <= 1'000'000 gwei <= 2**50 wei
                    // - hence gasCostEthWei <= 2**70
                    // - juelsPerFeeCoin <= 2**96 (more than the entire supply)
                    // we still fit into 166 bits
                    uint256 gasCostJuels = (gasCostEthWei * uint192(juelsPerFeeCoin))/1e18;
                    uint96 oldTransmitterPaymentJuels = s_transmitters[transmitter].paymentJuels;
                    uint96 newTransmitterPaymentJuels = uint96(uint256(oldTransmitterPaymentJuels) +
                      gasCostJuels + uint256(hotVars.transmissionPaymentGjuels) * (1 gwei));
                    // overflow *should* never happen, but if it does, let's not persist it.
                    if (newTransmitterPaymentJuels < oldTransmitterPaymentJuels) {
                      return;
                    }
                    s_transmitters[transmitter].paymentJuels = newTransmitterPaymentJuels;
                  }
                }
                /***************************************************************************
                 * Section: Payee Management
                 **************************************************************************/
                // Addresses at which oracles want to receive payments, by transmitter address
                mapping (address /* transmitter */ => address /* payment address */)
                  internal
                  s_payees;
                // Payee addresses which must be approved by the owner
                mapping (address /* transmitter */ => address /* payment address */)
                  internal
                  s_proposedPayees;
                /**
                 * @notice emitted when a transfer of an oracle's payee address has been initiated
                 * @param transmitter address from which the oracle sends reports to the transmit method
                 * @param current the payee address for the oracle, prior to this setting
                 * @param proposed the proposed new payee address for the oracle
                 */
                event PayeeshipTransferRequested(
                  address indexed transmitter,
                  address indexed current,
                  address indexed proposed
                );
                /**
                 * @notice emitted when a transfer of an oracle's payee address has been completed
                 * @param transmitter address from which the oracle sends reports to the transmit method
                 * @param current the payee address for the oracle, prior to this setting
                 */
                event PayeeshipTransferred(
                  address indexed transmitter,
                  address indexed previous,
                  address indexed current
                );
                /**
                 * @notice sets the payees for transmitting addresses
                 * @param transmitters addresses oracles use to transmit the reports
                 * @param payees addresses of payees corresponding to list of transmitters
                 * @dev must be called by owner
                 * @dev cannot be used to change payee addresses, only to initially populate them
                 */
                function setPayees(
                  address[] calldata transmitters,
                  address[] calldata payees
                )
                  external
                  onlyOwner()
                {
                  require(transmitters.length == payees.length, "transmitters.size != payees.size");
                  for (uint i = 0; i < transmitters.length; i++) {
                    address transmitter = transmitters[i];
                    address payee = payees[i];
                    address currentPayee = s_payees[transmitter];
                    bool zeroedOut = currentPayee == address(0);
                    require(zeroedOut || currentPayee == payee, "payee already set");
                    s_payees[transmitter] = payee;
                    if (currentPayee != payee) {
                      emit PayeeshipTransferred(transmitter, currentPayee, payee);
                    }
                  }
                }
                /**
                 * @notice first step of payeeship transfer (safe transfer pattern)
                 * @param transmitter transmitter address of oracle whose payee is changing
                 * @param proposed new payee address
                 * @dev can only be called by payee address
                 */
                function transferPayeeship(
                  address transmitter,
                  address proposed
                )
                  external
                {
                  require(msg.sender == s_payees[transmitter], "only current payee can update");
                  require(msg.sender != proposed, "cannot transfer to self");
                  address previousProposed = s_proposedPayees[transmitter];
                  s_proposedPayees[transmitter] = proposed;
                  if (previousProposed != proposed) {
                    emit PayeeshipTransferRequested(transmitter, msg.sender, proposed);
                  }
                }
                /**
                 * @notice second step of payeeship transfer (safe transfer pattern)
                 * @param transmitter transmitter address of oracle whose payee is changing
                 * @dev can only be called by proposed new payee address
                 */
                function acceptPayeeship(
                  address transmitter
                )
                  external
                {
                  require(msg.sender == s_proposedPayees[transmitter], "only proposed payees can accept");
                  address currentPayee = s_payees[transmitter];
                  s_payees[transmitter] = msg.sender;
                  s_proposedPayees[transmitter] = address(0);
                  emit PayeeshipTransferred(transmitter, currentPayee, msg.sender);
                }
                /***************************************************************************
                 * Section: TypeAndVersionInterface
                 **************************************************************************/
                function typeAndVersion()
                  external
                  override
                  pure
                  virtual
                  returns (string memory)
                {
                  return "OCR2Aggregator 1.0.0";
                }
                /***************************************************************************
                 * Section: Helper Functions
                 **************************************************************************/
                function _min(
                  uint256 a,
                  uint256 b
                )
                  internal
                  pure
                  returns (uint256)
                {
                  unchecked {
                    if (a < b) { return a; }
                    return b;
                  }
                }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity =0.8.19;
              import "./interfaces/TypeAndVersionInterface.sol";
              import "./lib/ConfigDigestUtilEVMSimple.sol";
              import "./OwnerIsCreator.sol";
              import "./OCR2Abstract.sol";
              /// @title OCRConfigurationStoreEVMSimple
              /// @notice This contract stores configurations for protocol versions OCR2 and
              /// above in contract storage. It uses the "EVMSimple" config digester.
              contract OCRConfigurationStoreEVMSimple is TypeAndVersionInterface {
                  struct ConfigurationEVMSimple {
                      address[] signers;
                      address[] transmitters;
                      bytes onchainConfig;
                      bytes offchainConfig;
                      address contractAddress;
                      uint64 offchainConfigVersion;
                      uint32 configCount;
                      uint8 f;
                  }
                  /// @notice a list of configurations keyed by their digest
                  mapping(bytes32 => ConfigurationEVMSimple) internal s_configurations;
                  /// @notice emitted when a new configuration is added
                  event NewConfiguration(bytes32 indexed configDigest);
                  /// @notice adds a new configuration to the store
                  function addConfig(ConfigurationEVMSimple calldata configuration) external returns (bytes32) {
                      bytes32 configDigest = ConfigDigestUtilEVMSimple.configDigestFromConfigData(
                          block.chainid,
                          configuration.contractAddress,
                          configuration.configCount,
                          configuration.signers,
                          configuration.transmitters,
                          configuration.f,
                          configuration.onchainConfig,
                          configuration.offchainConfigVersion,
                          configuration.offchainConfig
                      );
                      s_configurations[configDigest] = configuration;
                      emit NewConfiguration(configDigest);
                      return configDigest;
                  }
                  /// @notice reads a configuration from the store
                  function readConfig(bytes32 configDigest) external view returns (ConfigurationEVMSimple memory) {
                      return s_configurations[configDigest];
                  }
                  /// @inheritdoc TypeAndVersionInterface
                  function typeAndVersion() external override pure virtual returns (string memory)
                  {
                      return "OCRConfigurationStoreEVMSimple 1.0.0";
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./ConfirmedOwner.sol";
              /**
               * @title The OwnerIsCreator contract
               * @notice A contract with helpers for basic contract ownership.
               */
              contract OwnerIsCreator is ConfirmedOwner {
                constructor(
                )
                  ConfirmedOwner(
                    msg.sender
                  )
                {
                }
              }// SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./SimpleWriteAccessController.sol";
              /**
               * @title SimpleReadAccessController
               * @notice Gives access to:
               * - any externally owned account (note that offchain actors can always read
               * any contract storage regardless of onchain access control measures, so this
               * does not weaken the access control while improving usability)
               * - accounts explicitly added to an access list
               * @dev SimpleReadAccessController is not suitable for access controlling writes
               * since it grants any externally owned account access! See
               * SimpleWriteAccessController for that.
               */
              contract SimpleReadAccessController is SimpleWriteAccessController {
                /**
                 * @notice Returns the access of an address
                 * @param _user The address to query
                 */
                function hasAccess(
                  address _user,
                  bytes memory _calldata
                )
                  public
                  view
                  virtual
                  override
                  returns (bool)
                {
                  return super.hasAccess(_user, _calldata) || _user == tx.origin;
                }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./OwnerIsCreator.sol";
              import "./interfaces/AccessControllerInterface.sol";
              /**
               * @title SimpleWriteAccessController
               * @notice Gives access to accounts explicitly added to an access list by the
               * controller's owner.
               * @dev does not make any special permissions for externally, see
               * SimpleReadAccessController for that.
               */
              contract SimpleWriteAccessController is AccessControllerInterface, OwnerIsCreator {
                bool public checkEnabled;
                mapping(address => bool) internal accessList;
                event AddedAccess(address user);
                event RemovedAccess(address user);
                event CheckAccessEnabled();
                event CheckAccessDisabled();
                constructor()
                // TODO
                // this is modified from the version in the Chainlink monorepo
                //  OwnerIsCreator()
                {
                  checkEnabled = true;
                }
                /**
                 * @notice Returns the access of an address
                 * @param _user The address to query
                 */
                function hasAccess(
                  address _user,
                  bytes memory
                )
                  public
                  view
                  virtual
                  override
                  returns (bool)
                {
                  return accessList[_user] || !checkEnabled;
                }
                /**
                 * @notice Adds an address to the access list
                 * @param _user The address to add
                 */
                function addAccess(address _user)
                  external
                  onlyOwner()
                {
                  if (!accessList[_user]) {
                    accessList[_user] = true;
                    emit AddedAccess(_user);
                  }
                }
                /**
                 * @notice Removes an address from the access list
                 * @param _user The address to remove
                 */
                function removeAccess(address _user)
                  external
                  onlyOwner()
                {
                  if (accessList[_user]) {
                    accessList[_user] = false;
                    emit RemovedAccess(_user);
                  }
                }
                /**
                 * @notice makes the access check enforced
                 */
                function enableAccessCheck()
                  external
                  onlyOwner()
                {
                  if (!checkEnabled) {
                    checkEnabled = true;
                    emit CheckAccessEnabled();
                  }
                }
                /**
                 * @notice makes the access check unenforced
                 */
                function disableAccessCheck()
                  external
                  onlyOwner()
                {
                  if (checkEnabled) {
                    checkEnabled = false;
                    emit CheckAccessDisabled();
                  }
                }
                /**
                 * @dev reverts if the caller does not have access
                 */
                modifier checkAccess() {
                  require(hasAccess(msg.sender, msg.data), "No access");
                  _;
                }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface AccessControllerInterface {
                function hasAccess(address user, bytes calldata data) external view returns (bool);
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface AggregatorInterface {
                function latestAnswer() external view returns (int256);
                function latestTimestamp() external view returns (uint256);
                function latestRound() external view returns (uint256);
                function getAnswer(uint256 roundId) external view returns (int256);
                function getTimestamp(uint256 roundId) external view returns (uint256);
                event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);
                event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              import "./AggregatorInterface.sol";
              import "./AggregatorV3Interface.sol";
              interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface
              {
              }// SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface AggregatorV3Interface {
                function decimals() external view returns (uint8);
                function description() external view returns (string memory);
                function version() external view returns (uint256);
                function getRoundData(uint80 _roundId)
                  external
                  view
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  );
                function latestRoundData()
                  external
                  view
                  returns (
                    uint80 roundId,
                    int256 answer,
                    uint256 startedAt,
                    uint256 updatedAt,
                    uint80 answeredInRound
                  );
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface AggregatorValidatorInterface {
                function validate(
                  uint256 previousRoundId,
                  int256 previousAnswer,
                  uint256 currentRoundId,
                  int256 currentAnswer
                ) external returns (bool);
              }// SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface LinkTokenInterface {
                function allowance(address owner, address spender) external view returns (uint256 remaining);
                function approve(address spender, uint256 value) external returns (bool success);
                function balanceOf(address owner) external view returns (uint256 balance);
                function decimals() external view returns (uint8 decimalPlaces);
                function decreaseApproval(address spender, uint256 addedValue) external returns (bool success);
                function increaseApproval(address spender, uint256 subtractedValue) external;
                function name() external view returns (string memory tokenName);
                function symbol() external view returns (string memory tokenSymbol);
                function totalSupply() external view returns (uint256 totalTokensIssued);
                function transfer(address to, uint256 value) external returns (bool success);
                function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool success);
                function transferFrom(address from, address to, uint256 value) external returns (bool success);
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface OwnableInterface {
                function owner()
                  external
                  returns (
                    address
                  );
                function transferOwnership(
                  address recipient
                )
                  external;
                function acceptOwnership()
                  external;
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              interface TypeAndVersionInterface{
                function typeAndVersion()
                  external
                  pure
                  returns (string memory);
              }// SPDX-License-Identifier: MIT
              pragma solidity ^0.8.0;
              /// @title ConfigDigestUtilEVMSimple
              /// @notice ConfigDigest related utility functions for "EVMSimple" config
              /// digester
              library ConfigDigestUtilEVMSimple {
                  function configDigestFromConfigData(
                      uint256 chainId,
                      address contractAddress,
                      uint64 configCount,
                      address[] memory signers,
                      address[] memory transmitters,
                      uint8 f,
                      bytes memory onchainConfig,
                      uint64 offchainConfigVersion,
                      bytes memory offchainConfig
                  ) internal pure returns (bytes32)
                  {
                      uint256 hash = uint256(
                          keccak256(
                              abi.encode(
                                  chainId,
                                  contractAddress,
                                  configCount,
                                  signers,
                                  transmitters,
                                  f,
                                  onchainConfig,
                                  offchainConfigVersion,
                                  offchainConfig
                      )));
                      uint256 prefixMask = type(uint256).max << (256-16); // 0xFFFF00..00
                      uint256 prefix = 0x0001 << (256-16); // 0x000100..00
                      return bytes32((prefix & prefixMask) | (hash & ~prefixMask));
                  }
              }