ETH Price: $2,392.62 (-1.44%)

Transaction Decoder

Block:
19386966 at Mar-08-2024 12:47:11 AM +UTC
Transaction Fee:
0.00824086292496579 ETH $19.72
Gas Used:
132,393 Gas / 62.24545803 Gwei

Emitted Events:

36 RibbonToken.Transfer( from=0xFE0df74636Bc25C7F2400F22fe7dAE32D39443d2, to=[Sender] 0xf5213a6a2f0890321712520b8048d9886c1a9900, value=3799600000000000000000 )
37 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x000000000000000000000000f5213a6a2f0890321712520b8048d9886c1a9900, 0x000000000000000000000000fe0df74636bc25c7f2400f22fe7dae32d39443d2, 00000000000000000000000000000000000000000000000000000001453b15b0 )
38 0xfe0df74636bc25c7f2400f22fe7dae32d39443d2.0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67( 0xc42079f94a6350d7e6235f29174924f928cc2ac818eb64fed8004e115fbcca67, 0x000000000000000000000000e592427a0aece92de3edee1f18e0157c05861564, 0x000000000000000000000000f5213a6a2f0890321712520b8048d9886c1a9900, ffffffffffffffffffffffffffffffffffffffffffffff3205f51b24c1c80000, 00000000000000000000000000000000000000000000000000000001453b15b0, 0000000000000000000000000000000000000000000014135b45d6bd72dbd946, 000000000000000000000000000000000000000000000003b32d517841f71707, fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffbd6a1 )

Account State Difference:

  Address   Before After State Difference Code
0x6123B004...d4121fA6B
(beaverbuild)
16.408038637588543182 Eth16.409384748484973973 Eth0.001346110896430791
0xA0b86991...E3606eB48
0xf5213a6a...86c1A9900
3.644757347929624091 Eth
Nonce: 34251
3.636516485004658301 Eth
Nonce: 34252
0.00824086292496579
0xFE0df746...2D39443d2
(Uniswap V3: RBN-USDC 2)

Execution Trace

SwapRouter.exactOutputSingle( params=[{name:tokenIn, type:address, order:1, indexed:false, value:0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, valueString:0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48}, {name:tokenOut, type:address, order:2, indexed:false, value:0x6123B0049F904d730dB3C36a31167D9d4121fA6B, valueString:0x6123B0049F904d730dB3C36a31167D9d4121fA6B}, {name:fee, type:uint24, order:3, indexed:false, value:3000, valueString:3000}, {name:recipient, type:address, order:4, indexed:false, value:0xf5213a6a2f0890321712520b8048D9886c1A9900, valueString:0xf5213a6a2f0890321712520b8048D9886c1A9900}, {name:deadline, type:uint256, order:5, indexed:false, value:1709858950, valueString:1709858950}, {name:amountOut, type:uint256, order:6, indexed:false, value:3799600000000000000000, valueString:3799600000000000000000}, {name:amountInMaximum, type:uint256, order:7, indexed:false, value:5456491571, valueString:5456491571}, {name:sqrtPriceLimitX96, type:uint160, order:8, indexed:false, value:0, valueString:0}] ) => ( amountIn=5456467376 )
  • Uniswap V3: RBN-USDC 2.128acb08( )
    • RibbonToken.transfer( recipient=0xf5213a6a2f0890321712520b8048D9886c1A9900, amount=3799600000000000000000 ) => ( True )
    • FiatTokenProxy.70a08231( )
      • FiatTokenV2_2.balanceOf( account=0xFE0df74636Bc25C7F2400F22fe7dAE32D39443d2 ) => ( 10163509834476 )
      • SwapRouter.uniswapV3SwapCallback( amount0Delta=-3799600000000000000000, amount1Delta=5456467376, _data=0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000040000000000000000000000000F5213A6A2F0890321712520B8048D9886C1A9900000000000000000000000000000000000000000000000000000000000000002B6123B0049F904D730DB3C36A31167D9D4121FA6B000BB8A0B86991C6218B36C1D19D4A2E9EB0CE3606EB48000000000000000000000000000000000000000000 )
        • FiatTokenProxy.23b872dd( )
          • FiatTokenV2_2.transferFrom( from=0xf5213a6a2f0890321712520b8048D9886c1A9900, to=0xFE0df74636Bc25C7F2400F22fe7dAE32D39443d2, value=5456467376 ) => ( True )
          • FiatTokenProxy.70a08231( )
            • FiatTokenV2_2.balanceOf( account=0xFE0df74636Bc25C7F2400F22fe7dAE32D39443d2 ) => ( 10168966301852 )
              File 1 of 4: SwapRouter
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              pragma abicoder v2;
              import '@uniswap/v3-core/contracts/libraries/SafeCast.sol';
              import '@uniswap/v3-core/contracts/libraries/TickMath.sol';
              import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
              import './interfaces/ISwapRouter.sol';
              import './base/PeripheryImmutableState.sol';
              import './base/PeripheryValidation.sol';
              import './base/PeripheryPaymentsWithFee.sol';
              import './base/Multicall.sol';
              import './base/SelfPermit.sol';
              import './libraries/Path.sol';
              import './libraries/PoolAddress.sol';
              import './libraries/CallbackValidation.sol';
              import './interfaces/external/IWETH9.sol';
              /// @title Uniswap V3 Swap Router
              /// @notice Router for stateless execution of swaps against Uniswap V3
              contract SwapRouter is
                  ISwapRouter,
                  PeripheryImmutableState,
                  PeripheryValidation,
                  PeripheryPaymentsWithFee,
                  Multicall,
                  SelfPermit
              {
                  using Path for bytes;
                  using SafeCast for uint256;
                  /// @dev Used as the placeholder value for amountInCached, because the computed amount in for an exact output swap
                  /// can never actually be this value
                  uint256 private constant DEFAULT_AMOUNT_IN_CACHED = type(uint256).max;
                  /// @dev Transient storage variable used for returning the computed amount in for an exact output swap.
                  uint256 private amountInCached = DEFAULT_AMOUNT_IN_CACHED;
                  constructor(address _factory, address _WETH9) PeripheryImmutableState(_factory, _WETH9) {}
                  /// @dev Returns the pool for the given token pair and fee. The pool contract may or may not exist.
                  function getPool(
                      address tokenA,
                      address tokenB,
                      uint24 fee
                  ) private view returns (IUniswapV3Pool) {
                      return IUniswapV3Pool(PoolAddress.computeAddress(factory, PoolAddress.getPoolKey(tokenA, tokenB, fee)));
                  }
                  struct SwapCallbackData {
                      bytes path;
                      address payer;
                  }
                  /// @inheritdoc IUniswapV3SwapCallback
                  function uniswapV3SwapCallback(
                      int256 amount0Delta,
                      int256 amount1Delta,
                      bytes calldata _data
                  ) external override {
                      require(amount0Delta > 0 || amount1Delta > 0); // swaps entirely within 0-liquidity regions are not supported
                      SwapCallbackData memory data = abi.decode(_data, (SwapCallbackData));
                      (address tokenIn, address tokenOut, uint24 fee) = data.path.decodeFirstPool();
                      CallbackValidation.verifyCallback(factory, tokenIn, tokenOut, fee);
                      (bool isExactInput, uint256 amountToPay) =
                          amount0Delta > 0
                              ? (tokenIn < tokenOut, uint256(amount0Delta))
                              : (tokenOut < tokenIn, uint256(amount1Delta));
                      if (isExactInput) {
                          pay(tokenIn, data.payer, msg.sender, amountToPay);
                      } else {
                          // either initiate the next swap or pay
                          if (data.path.hasMultiplePools()) {
                              data.path = data.path.skipToken();
                              exactOutputInternal(amountToPay, msg.sender, 0, data);
                          } else {
                              amountInCached = amountToPay;
                              tokenIn = tokenOut; // swap in/out because exact output swaps are reversed
                              pay(tokenIn, data.payer, msg.sender, amountToPay);
                          }
                      }
                  }
                  /// @dev Performs a single exact input swap
                  function exactInputInternal(
                      uint256 amountIn,
                      address recipient,
                      uint160 sqrtPriceLimitX96,
                      SwapCallbackData memory data
                  ) private returns (uint256 amountOut) {
                      // allow swapping to the router address with address 0
                      if (recipient == address(0)) recipient = address(this);
                      (address tokenIn, address tokenOut, uint24 fee) = data.path.decodeFirstPool();
                      bool zeroForOne = tokenIn < tokenOut;
                      (int256 amount0, int256 amount1) =
                          getPool(tokenIn, tokenOut, fee).swap(
                              recipient,
                              zeroForOne,
                              amountIn.toInt256(),
                              sqrtPriceLimitX96 == 0
                                  ? (zeroForOne ? TickMath.MIN_SQRT_RATIO + 1 : TickMath.MAX_SQRT_RATIO - 1)
                                  : sqrtPriceLimitX96,
                              abi.encode(data)
                          );
                      return uint256(-(zeroForOne ? amount1 : amount0));
                  }
                  /// @inheritdoc ISwapRouter
                  function exactInputSingle(ExactInputSingleParams calldata params)
                      external
                      payable
                      override
                      checkDeadline(params.deadline)
                      returns (uint256 amountOut)
                  {
                      amountOut = exactInputInternal(
                          params.amountIn,
                          params.recipient,
                          params.sqrtPriceLimitX96,
                          SwapCallbackData({path: abi.encodePacked(params.tokenIn, params.fee, params.tokenOut), payer: msg.sender})
                      );
                      require(amountOut >= params.amountOutMinimum, 'Too little received');
                  }
                  /// @inheritdoc ISwapRouter
                  function exactInput(ExactInputParams memory params)
                      external
                      payable
                      override
                      checkDeadline(params.deadline)
                      returns (uint256 amountOut)
                  {
                      address payer = msg.sender; // msg.sender pays for the first hop
                      while (true) {
                          bool hasMultiplePools = params.path.hasMultiplePools();
                          // the outputs of prior swaps become the inputs to subsequent ones
                          params.amountIn = exactInputInternal(
                              params.amountIn,
                              hasMultiplePools ? address(this) : params.recipient, // for intermediate swaps, this contract custodies
                              0,
                              SwapCallbackData({
                                  path: params.path.getFirstPool(), // only the first pool in the path is necessary
                                  payer: payer
                              })
                          );
                          // decide whether to continue or terminate
                          if (hasMultiplePools) {
                              payer = address(this); // at this point, the caller has paid
                              params.path = params.path.skipToken();
                          } else {
                              amountOut = params.amountIn;
                              break;
                          }
                      }
                      require(amountOut >= params.amountOutMinimum, 'Too little received');
                  }
                  /// @dev Performs a single exact output swap
                  function exactOutputInternal(
                      uint256 amountOut,
                      address recipient,
                      uint160 sqrtPriceLimitX96,
                      SwapCallbackData memory data
                  ) private returns (uint256 amountIn) {
                      // allow swapping to the router address with address 0
                      if (recipient == address(0)) recipient = address(this);
                      (address tokenOut, address tokenIn, uint24 fee) = data.path.decodeFirstPool();
                      bool zeroForOne = tokenIn < tokenOut;
                      (int256 amount0Delta, int256 amount1Delta) =
                          getPool(tokenIn, tokenOut, fee).swap(
                              recipient,
                              zeroForOne,
                              -amountOut.toInt256(),
                              sqrtPriceLimitX96 == 0
                                  ? (zeroForOne ? TickMath.MIN_SQRT_RATIO + 1 : TickMath.MAX_SQRT_RATIO - 1)
                                  : sqrtPriceLimitX96,
                              abi.encode(data)
                          );
                      uint256 amountOutReceived;
                      (amountIn, amountOutReceived) = zeroForOne
                          ? (uint256(amount0Delta), uint256(-amount1Delta))
                          : (uint256(amount1Delta), uint256(-amount0Delta));
                      // it's technically possible to not receive the full output amount,
                      // so if no price limit has been specified, require this possibility away
                      if (sqrtPriceLimitX96 == 0) require(amountOutReceived == amountOut);
                  }
                  /// @inheritdoc ISwapRouter
                  function exactOutputSingle(ExactOutputSingleParams calldata params)
                      external
                      payable
                      override
                      checkDeadline(params.deadline)
                      returns (uint256 amountIn)
                  {
                      // avoid an SLOAD by using the swap return data
                      amountIn = exactOutputInternal(
                          params.amountOut,
                          params.recipient,
                          params.sqrtPriceLimitX96,
                          SwapCallbackData({path: abi.encodePacked(params.tokenOut, params.fee, params.tokenIn), payer: msg.sender})
                      );
                      require(amountIn <= params.amountInMaximum, 'Too much requested');
                      // has to be reset even though we don't use it in the single hop case
                      amountInCached = DEFAULT_AMOUNT_IN_CACHED;
                  }
                  /// @inheritdoc ISwapRouter
                  function exactOutput(ExactOutputParams calldata params)
                      external
                      payable
                      override
                      checkDeadline(params.deadline)
                      returns (uint256 amountIn)
                  {
                      // it's okay that the payer is fixed to msg.sender here, as they're only paying for the "final" exact output
                      // swap, which happens first, and subsequent swaps are paid for within nested callback frames
                      exactOutputInternal(
                          params.amountOut,
                          params.recipient,
                          0,
                          SwapCallbackData({path: params.path, payer: msg.sender})
                      );
                      amountIn = amountInCached;
                      require(amountIn <= params.amountInMaximum, 'Too much requested');
                      amountInCached = DEFAULT_AMOUNT_IN_CACHED;
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Safe casting methods
              /// @notice Contains methods for safely casting between types
              library SafeCast {
                  /// @notice Cast a uint256 to a uint160, revert on overflow
                  /// @param y The uint256 to be downcasted
                  /// @return z The downcasted integer, now type uint160
                  function toUint160(uint256 y) internal pure returns (uint160 z) {
                      require((z = uint160(y)) == y);
                  }
                  /// @notice Cast a int256 to a int128, revert on overflow or underflow
                  /// @param y The int256 to be downcasted
                  /// @return z The downcasted integer, now type int128
                  function toInt128(int256 y) internal pure returns (int128 z) {
                      require((z = int128(y)) == y);
                  }
                  /// @notice Cast a uint256 to a int256, revert on overflow
                  /// @param y The uint256 to be casted
                  /// @return z The casted integer, now type int256
                  function toInt256(uint256 y) internal pure returns (int256 z) {
                      require(y < 2**255);
                      z = int256(y);
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Math library for computing sqrt prices from ticks and vice versa
              /// @notice Computes sqrt price for ticks of size 1.0001, i.e. sqrt(1.0001^tick) as fixed point Q64.96 numbers. Supports
              /// prices between 2**-128 and 2**128
              library TickMath {
                  /// @dev The minimum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**-128
                  int24 internal constant MIN_TICK = -887272;
                  /// @dev The maximum tick that may be passed to #getSqrtRatioAtTick computed from log base 1.0001 of 2**128
                  int24 internal constant MAX_TICK = -MIN_TICK;
                  /// @dev The minimum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MIN_TICK)
                  uint160 internal constant MIN_SQRT_RATIO = 4295128739;
                  /// @dev The maximum value that can be returned from #getSqrtRatioAtTick. Equivalent to getSqrtRatioAtTick(MAX_TICK)
                  uint160 internal constant MAX_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
                  /// @notice Calculates sqrt(1.0001^tick) * 2^96
                  /// @dev Throws if |tick| > max tick
                  /// @param tick The input tick for the above formula
                  /// @return sqrtPriceX96 A Fixed point Q64.96 number representing the sqrt of the ratio of the two assets (token1/token0)
                  /// at the given tick
                  function getSqrtRatioAtTick(int24 tick) internal pure returns (uint160 sqrtPriceX96) {
                      uint256 absTick = tick < 0 ? uint256(-int256(tick)) : uint256(int256(tick));
                      require(absTick <= uint256(MAX_TICK), 'T');
                      uint256 ratio = absTick & 0x1 != 0 ? 0xfffcb933bd6fad37aa2d162d1a594001 : 0x100000000000000000000000000000000;
                      if (absTick & 0x2 != 0) ratio = (ratio * 0xfff97272373d413259a46990580e213a) >> 128;
                      if (absTick & 0x4 != 0) ratio = (ratio * 0xfff2e50f5f656932ef12357cf3c7fdcc) >> 128;
                      if (absTick & 0x8 != 0) ratio = (ratio * 0xffe5caca7e10e4e61c3624eaa0941cd0) >> 128;
                      if (absTick & 0x10 != 0) ratio = (ratio * 0xffcb9843d60f6159c9db58835c926644) >> 128;
                      if (absTick & 0x20 != 0) ratio = (ratio * 0xff973b41fa98c081472e6896dfb254c0) >> 128;
                      if (absTick & 0x40 != 0) ratio = (ratio * 0xff2ea16466c96a3843ec78b326b52861) >> 128;
                      if (absTick & 0x80 != 0) ratio = (ratio * 0xfe5dee046a99a2a811c461f1969c3053) >> 128;
                      if (absTick & 0x100 != 0) ratio = (ratio * 0xfcbe86c7900a88aedcffc83b479aa3a4) >> 128;
                      if (absTick & 0x200 != 0) ratio = (ratio * 0xf987a7253ac413176f2b074cf7815e54) >> 128;
                      if (absTick & 0x400 != 0) ratio = (ratio * 0xf3392b0822b70005940c7a398e4b70f3) >> 128;
                      if (absTick & 0x800 != 0) ratio = (ratio * 0xe7159475a2c29b7443b29c7fa6e889d9) >> 128;
                      if (absTick & 0x1000 != 0) ratio = (ratio * 0xd097f3bdfd2022b8845ad8f792aa5825) >> 128;
                      if (absTick & 0x2000 != 0) ratio = (ratio * 0xa9f746462d870fdf8a65dc1f90e061e5) >> 128;
                      if (absTick & 0x4000 != 0) ratio = (ratio * 0x70d869a156d2a1b890bb3df62baf32f7) >> 128;
                      if (absTick & 0x8000 != 0) ratio = (ratio * 0x31be135f97d08fd981231505542fcfa6) >> 128;
                      if (absTick & 0x10000 != 0) ratio = (ratio * 0x9aa508b5b7a84e1c677de54f3e99bc9) >> 128;
                      if (absTick & 0x20000 != 0) ratio = (ratio * 0x5d6af8dedb81196699c329225ee604) >> 128;
                      if (absTick & 0x40000 != 0) ratio = (ratio * 0x2216e584f5fa1ea926041bedfe98) >> 128;
                      if (absTick & 0x80000 != 0) ratio = (ratio * 0x48a170391f7dc42444e8fa2) >> 128;
                      if (tick > 0) ratio = type(uint256).max / ratio;
                      // this divides by 1<<32 rounding up to go from a Q128.128 to a Q128.96.
                      // we then downcast because we know the result always fits within 160 bits due to our tick input constraint
                      // we round up in the division so getTickAtSqrtRatio of the output price is always consistent
                      sqrtPriceX96 = uint160((ratio >> 32) + (ratio % (1 << 32) == 0 ? 0 : 1));
                  }
                  /// @notice Calculates the greatest tick value such that getRatioAtTick(tick) <= ratio
                  /// @dev Throws in case sqrtPriceX96 < MIN_SQRT_RATIO, as MIN_SQRT_RATIO is the lowest value getRatioAtTick may
                  /// ever return.
                  /// @param sqrtPriceX96 The sqrt ratio for which to compute the tick as a Q64.96
                  /// @return tick The greatest tick for which the ratio is less than or equal to the input ratio
                  function getTickAtSqrtRatio(uint160 sqrtPriceX96) internal pure returns (int24 tick) {
                      // second inequality must be < because the price can never reach the price at the max tick
                      require(sqrtPriceX96 >= MIN_SQRT_RATIO && sqrtPriceX96 < MAX_SQRT_RATIO, 'R');
                      uint256 ratio = uint256(sqrtPriceX96) << 32;
                      uint256 r = ratio;
                      uint256 msb = 0;
                      assembly {
                          let f := shl(7, gt(r, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := shl(6, gt(r, 0xFFFFFFFFFFFFFFFF))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := shl(5, gt(r, 0xFFFFFFFF))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := shl(4, gt(r, 0xFFFF))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := shl(3, gt(r, 0xFF))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := shl(2, gt(r, 0xF))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := shl(1, gt(r, 0x3))
                          msb := or(msb, f)
                          r := shr(f, r)
                      }
                      assembly {
                          let f := gt(r, 0x1)
                          msb := or(msb, f)
                      }
                      if (msb >= 128) r = ratio >> (msb - 127);
                      else r = ratio << (127 - msb);
                      int256 log_2 = (int256(msb) - 128) << 64;
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(63, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(62, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(61, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(60, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(59, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(58, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(57, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(56, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(55, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(54, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(53, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(52, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(51, f))
                          r := shr(f, r)
                      }
                      assembly {
                          r := shr(127, mul(r, r))
                          let f := shr(128, r)
                          log_2 := or(log_2, shl(50, f))
                      }
                      int256 log_sqrt10001 = log_2 * 255738958999603826347141; // 128.128 number
                      int24 tickLow = int24((log_sqrt10001 - 3402992956809132418596140100660247210) >> 128);
                      int24 tickHi = int24((log_sqrt10001 + 291339464771989622907027621153398088495) >> 128);
                      tick = tickLow == tickHi ? tickLow : getSqrtRatioAtTick(tickHi) <= sqrtPriceX96 ? tickHi : tickLow;
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              import './pool/IUniswapV3PoolImmutables.sol';
              import './pool/IUniswapV3PoolState.sol';
              import './pool/IUniswapV3PoolDerivedState.sol';
              import './pool/IUniswapV3PoolActions.sol';
              import './pool/IUniswapV3PoolOwnerActions.sol';
              import './pool/IUniswapV3PoolEvents.sol';
              /// @title The interface for a Uniswap V3 Pool
              /// @notice A Uniswap pool facilitates swapping and automated market making between any two assets that strictly conform
              /// to the ERC20 specification
              /// @dev The pool interface is broken up into many smaller pieces
              interface IUniswapV3Pool is
                  IUniswapV3PoolImmutables,
                  IUniswapV3PoolState,
                  IUniswapV3PoolDerivedState,
                  IUniswapV3PoolActions,
                  IUniswapV3PoolOwnerActions,
                  IUniswapV3PoolEvents
              {
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              pragma abicoder v2;
              import '@uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol';
              /// @title Router token swapping functionality
              /// @notice Functions for swapping tokens via Uniswap V3
              interface ISwapRouter is IUniswapV3SwapCallback {
                  struct ExactInputSingleParams {
                      address tokenIn;
                      address tokenOut;
                      uint24 fee;
                      address recipient;
                      uint256 deadline;
                      uint256 amountIn;
                      uint256 amountOutMinimum;
                      uint160 sqrtPriceLimitX96;
                  }
                  /// @notice Swaps `amountIn` of one token for as much as possible of another token
                  /// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
                  /// @return amountOut The amount of the received token
                  function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);
                  struct ExactInputParams {
                      bytes path;
                      address recipient;
                      uint256 deadline;
                      uint256 amountIn;
                      uint256 amountOutMinimum;
                  }
                  /// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
                  /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
                  /// @return amountOut The amount of the received token
                  function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);
                  struct ExactOutputSingleParams {
                      address tokenIn;
                      address tokenOut;
                      uint24 fee;
                      address recipient;
                      uint256 deadline;
                      uint256 amountOut;
                      uint256 amountInMaximum;
                      uint160 sqrtPriceLimitX96;
                  }
                  /// @notice Swaps as little as possible of one token for `amountOut` of another token
                  /// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
                  /// @return amountIn The amount of the input token
                  function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);
                  struct ExactOutputParams {
                      bytes path;
                      address recipient;
                      uint256 deadline;
                      uint256 amountOut;
                      uint256 amountInMaximum;
                  }
                  /// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
                  /// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
                  /// @return amountIn The amount of the input token
                  function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              import '../interfaces/IPeripheryImmutableState.sol';
              /// @title Immutable state
              /// @notice Immutable state used by periphery contracts
              abstract contract PeripheryImmutableState is IPeripheryImmutableState {
                  /// @inheritdoc IPeripheryImmutableState
                  address public immutable override factory;
                  /// @inheritdoc IPeripheryImmutableState
                  address public immutable override WETH9;
                  constructor(address _factory, address _WETH9) {
                      factory = _factory;
                      WETH9 = _WETH9;
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              import './BlockTimestamp.sol';
              abstract contract PeripheryValidation is BlockTimestamp {
                  modifier checkDeadline(uint256 deadline) {
                      require(_blockTimestamp() <= deadline, 'Transaction too old');
                      _;
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
              import '@uniswap/v3-core/contracts/libraries/LowGasSafeMath.sol';
              import './PeripheryPayments.sol';
              import '../interfaces/IPeripheryPaymentsWithFee.sol';
              import '../interfaces/external/IWETH9.sol';
              import '../libraries/TransferHelper.sol';
              abstract contract PeripheryPaymentsWithFee is PeripheryPayments, IPeripheryPaymentsWithFee {
                  using LowGasSafeMath for uint256;
                  /// @inheritdoc IPeripheryPaymentsWithFee
                  function unwrapWETH9WithFee(
                      uint256 amountMinimum,
                      address recipient,
                      uint256 feeBips,
                      address feeRecipient
                  ) public payable override {
                      require(feeBips > 0 && feeBips <= 100);
                      uint256 balanceWETH9 = IWETH9(WETH9).balanceOf(address(this));
                      require(balanceWETH9 >= amountMinimum, 'Insufficient WETH9');
                      if (balanceWETH9 > 0) {
                          IWETH9(WETH9).withdraw(balanceWETH9);
                          uint256 feeAmount = balanceWETH9.mul(feeBips) / 10_000;
                          if (feeAmount > 0) TransferHelper.safeTransferETH(feeRecipient, feeAmount);
                          TransferHelper.safeTransferETH(recipient, balanceWETH9 - feeAmount);
                      }
                  }
                  /// @inheritdoc IPeripheryPaymentsWithFee
                  function sweepTokenWithFee(
                      address token,
                      uint256 amountMinimum,
                      address recipient,
                      uint256 feeBips,
                      address feeRecipient
                  ) public payable override {
                      require(feeBips > 0 && feeBips <= 100);
                      uint256 balanceToken = IERC20(token).balanceOf(address(this));
                      require(balanceToken >= amountMinimum, 'Insufficient token');
                      if (balanceToken > 0) {
                          uint256 feeAmount = balanceToken.mul(feeBips) / 10_000;
                          if (feeAmount > 0) TransferHelper.safeTransfer(token, feeRecipient, feeAmount);
                          TransferHelper.safeTransfer(token, recipient, balanceToken - feeAmount);
                      }
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              pragma abicoder v2;
              import '../interfaces/IMulticall.sol';
              /// @title Multicall
              /// @notice Enables calling multiple methods in a single call to the contract
              abstract contract Multicall is IMulticall {
                  /// @inheritdoc IMulticall
                  function multicall(bytes[] calldata data) external payable override returns (bytes[] memory results) {
                      results = new bytes[](data.length);
                      for (uint256 i = 0; i < data.length; i++) {
                          (bool success, bytes memory result) = address(this).delegatecall(data[i]);
                          if (!success) {
                              // Next 5 lines from https://ethereum.stackexchange.com/a/83577
                              if (result.length < 68) revert();
                              assembly {
                                  result := add(result, 0x04)
                              }
                              revert(abi.decode(result, (string)));
                          }
                          results[i] = result;
                      }
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
              import '@openzeppelin/contracts/drafts/IERC20Permit.sol';
              import '../interfaces/ISelfPermit.sol';
              import '../interfaces/external/IERC20PermitAllowed.sol';
              /// @title Self Permit
              /// @notice Functionality to call permit on any EIP-2612-compliant token for use in the route
              /// @dev These functions are expected to be embedded in multicalls to allow EOAs to approve a contract and call a function
              /// that requires an approval in a single transaction.
              abstract contract SelfPermit is ISelfPermit {
                  /// @inheritdoc ISelfPermit
                  function selfPermit(
                      address token,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) public payable override {
                      IERC20Permit(token).permit(msg.sender, address(this), value, deadline, v, r, s);
                  }
                  /// @inheritdoc ISelfPermit
                  function selfPermitIfNecessary(
                      address token,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external payable override {
                      if (IERC20(token).allowance(msg.sender, address(this)) < value) selfPermit(token, value, deadline, v, r, s);
                  }
                  /// @inheritdoc ISelfPermit
                  function selfPermitAllowed(
                      address token,
                      uint256 nonce,
                      uint256 expiry,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) public payable override {
                      IERC20PermitAllowed(token).permit(msg.sender, address(this), nonce, expiry, true, v, r, s);
                  }
                  /// @inheritdoc ISelfPermit
                  function selfPermitAllowedIfNecessary(
                      address token,
                      uint256 nonce,
                      uint256 expiry,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external payable override {
                      if (IERC20(token).allowance(msg.sender, address(this)) < type(uint256).max)
                          selfPermitAllowed(token, nonce, expiry, v, r, s);
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.6.0;
              import './BytesLib.sol';
              /// @title Functions for manipulating path data for multihop swaps
              library Path {
                  using BytesLib for bytes;
                  /// @dev The length of the bytes encoded address
                  uint256 private constant ADDR_SIZE = 20;
                  /// @dev The length of the bytes encoded fee
                  uint256 private constant FEE_SIZE = 3;
                  /// @dev The offset of a single token address and pool fee
                  uint256 private constant NEXT_OFFSET = ADDR_SIZE + FEE_SIZE;
                  /// @dev The offset of an encoded pool key
                  uint256 private constant POP_OFFSET = NEXT_OFFSET + ADDR_SIZE;
                  /// @dev The minimum length of an encoding that contains 2 or more pools
                  uint256 private constant MULTIPLE_POOLS_MIN_LENGTH = POP_OFFSET + NEXT_OFFSET;
                  /// @notice Returns true iff the path contains two or more pools
                  /// @param path The encoded swap path
                  /// @return True if path contains two or more pools, otherwise false
                  function hasMultiplePools(bytes memory path) internal pure returns (bool) {
                      return path.length >= MULTIPLE_POOLS_MIN_LENGTH;
                  }
                  /// @notice Decodes the first pool in path
                  /// @param path The bytes encoded swap path
                  /// @return tokenA The first token of the given pool
                  /// @return tokenB The second token of the given pool
                  /// @return fee The fee level of the pool
                  function decodeFirstPool(bytes memory path)
                      internal
                      pure
                      returns (
                          address tokenA,
                          address tokenB,
                          uint24 fee
                      )
                  {
                      tokenA = path.toAddress(0);
                      fee = path.toUint24(ADDR_SIZE);
                      tokenB = path.toAddress(NEXT_OFFSET);
                  }
                  /// @notice Gets the segment corresponding to the first pool in the path
                  /// @param path The bytes encoded swap path
                  /// @return The segment containing all data necessary to target the first pool in the path
                  function getFirstPool(bytes memory path) internal pure returns (bytes memory) {
                      return path.slice(0, POP_OFFSET);
                  }
                  /// @notice Skips a token + fee element from the buffer and returns the remainder
                  /// @param path The swap path
                  /// @return The remaining token + fee elements in the path
                  function skipToken(bytes memory path) internal pure returns (bytes memory) {
                      return path.slice(NEXT_OFFSET, path.length - NEXT_OFFSET);
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Provides functions for deriving a pool address from the factory, tokens, and the fee
              library PoolAddress {
                  bytes32 internal constant POOL_INIT_CODE_HASH = 0xe34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54;
                  /// @notice The identifying key of the pool
                  struct PoolKey {
                      address token0;
                      address token1;
                      uint24 fee;
                  }
                  /// @notice Returns PoolKey: the ordered tokens with the matched fee levels
                  /// @param tokenA The first token of a pool, unsorted
                  /// @param tokenB The second token of a pool, unsorted
                  /// @param fee The fee level of the pool
                  /// @return Poolkey The pool details with ordered token0 and token1 assignments
                  function getPoolKey(
                      address tokenA,
                      address tokenB,
                      uint24 fee
                  ) internal pure returns (PoolKey memory) {
                      if (tokenA > tokenB) (tokenA, tokenB) = (tokenB, tokenA);
                      return PoolKey({token0: tokenA, token1: tokenB, fee: fee});
                  }
                  /// @notice Deterministically computes the pool address given the factory and PoolKey
                  /// @param factory The Uniswap V3 factory contract address
                  /// @param key The PoolKey
                  /// @return pool The contract address of the V3 pool
                  function computeAddress(address factory, PoolKey memory key) internal pure returns (address pool) {
                      require(key.token0 < key.token1);
                      pool = address(
                          uint256(
                              keccak256(
                                  abi.encodePacked(
                                      hex'ff',
                                      factory,
                                      keccak256(abi.encode(key.token0, key.token1, key.fee)),
                                      POOL_INIT_CODE_HASH
                                  )
                              )
                          )
                      );
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              import '@uniswap/v3-core/contracts/interfaces/IUniswapV3Pool.sol';
              import './PoolAddress.sol';
              /// @notice Provides validation for callbacks from Uniswap V3 Pools
              library CallbackValidation {
                  /// @notice Returns the address of a valid Uniswap V3 Pool
                  /// @param factory The contract address of the Uniswap V3 factory
                  /// @param tokenA The contract address of either token0 or token1
                  /// @param tokenB The contract address of the other token
                  /// @param fee The fee collected upon every swap in the pool, denominated in hundredths of a bip
                  /// @return pool The V3 pool contract address
                  function verifyCallback(
                      address factory,
                      address tokenA,
                      address tokenB,
                      uint24 fee
                  ) internal view returns (IUniswapV3Pool pool) {
                      return verifyCallback(factory, PoolAddress.getPoolKey(tokenA, tokenB, fee));
                  }
                  /// @notice Returns the address of a valid Uniswap V3 Pool
                  /// @param factory The contract address of the Uniswap V3 factory
                  /// @param poolKey The identifying key of the V3 pool
                  /// @return pool The V3 pool contract address
                  function verifyCallback(address factory, PoolAddress.PoolKey memory poolKey)
                      internal
                      view
                      returns (IUniswapV3Pool pool)
                  {
                      pool = IUniswapV3Pool(PoolAddress.computeAddress(factory, poolKey));
                      require(msg.sender == address(pool));
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
              /// @title Interface for WETH9
              interface IWETH9 is IERC20 {
                  /// @notice Deposit ether to get wrapped ether
                  function deposit() external payable;
                  /// @notice Withdraw wrapped ether to get ether
                  function withdraw(uint256) external;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Pool state that never changes
              /// @notice These parameters are fixed for a pool forever, i.e., the methods will always return the same values
              interface IUniswapV3PoolImmutables {
                  /// @notice The contract that deployed the pool, which must adhere to the IUniswapV3Factory interface
                  /// @return The contract address
                  function factory() external view returns (address);
                  /// @notice The first of the two tokens of the pool, sorted by address
                  /// @return The token contract address
                  function token0() external view returns (address);
                  /// @notice The second of the two tokens of the pool, sorted by address
                  /// @return The token contract address
                  function token1() external view returns (address);
                  /// @notice The pool's fee in hundredths of a bip, i.e. 1e-6
                  /// @return The fee
                  function fee() external view returns (uint24);
                  /// @notice The pool tick spacing
                  /// @dev Ticks can only be used at multiples of this value, minimum of 1 and always positive
                  /// e.g.: a tickSpacing of 3 means ticks can be initialized every 3rd tick, i.e., ..., -6, -3, 0, 3, 6, ...
                  /// This value is an int24 to avoid casting even though it is always positive.
                  /// @return The tick spacing
                  function tickSpacing() external view returns (int24);
                  /// @notice The maximum amount of position liquidity that can use any tick in the range
                  /// @dev This parameter is enforced per tick to prevent liquidity from overflowing a uint128 at any point, and
                  /// also prevents out-of-range liquidity from being used to prevent adding in-range liquidity to a pool
                  /// @return The max amount of liquidity per tick
                  function maxLiquidityPerTick() external view returns (uint128);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Pool state that can change
              /// @notice These methods compose the pool's state, and can change with any frequency including multiple times
              /// per transaction
              interface IUniswapV3PoolState {
                  /// @notice The 0th storage slot in the pool stores many values, and is exposed as a single method to save gas
                  /// when accessed externally.
                  /// @return sqrtPriceX96 The current price of the pool as a sqrt(token1/token0) Q64.96 value
                  /// tick The current tick of the pool, i.e. according to the last tick transition that was run.
                  /// This value may not always be equal to SqrtTickMath.getTickAtSqrtRatio(sqrtPriceX96) if the price is on a tick
                  /// boundary.
                  /// observationIndex The index of the last oracle observation that was written,
                  /// observationCardinality The current maximum number of observations stored in the pool,
                  /// observationCardinalityNext The next maximum number of observations, to be updated when the observation.
                  /// feeProtocol The protocol fee for both tokens of the pool.
                  /// Encoded as two 4 bit values, where the protocol fee of token1 is shifted 4 bits and the protocol fee of token0
                  /// is the lower 4 bits. Used as the denominator of a fraction of the swap fee, e.g. 4 means 1/4th of the swap fee.
                  /// unlocked Whether the pool is currently locked to reentrancy
                  function slot0()
                      external
                      view
                      returns (
                          uint160 sqrtPriceX96,
                          int24 tick,
                          uint16 observationIndex,
                          uint16 observationCardinality,
                          uint16 observationCardinalityNext,
                          uint8 feeProtocol,
                          bool unlocked
                      );
                  /// @notice The fee growth as a Q128.128 fees of token0 collected per unit of liquidity for the entire life of the pool
                  /// @dev This value can overflow the uint256
                  function feeGrowthGlobal0X128() external view returns (uint256);
                  /// @notice The fee growth as a Q128.128 fees of token1 collected per unit of liquidity for the entire life of the pool
                  /// @dev This value can overflow the uint256
                  function feeGrowthGlobal1X128() external view returns (uint256);
                  /// @notice The amounts of token0 and token1 that are owed to the protocol
                  /// @dev Protocol fees will never exceed uint128 max in either token
                  function protocolFees() external view returns (uint128 token0, uint128 token1);
                  /// @notice The currently in range liquidity available to the pool
                  /// @dev This value has no relationship to the total liquidity across all ticks
                  function liquidity() external view returns (uint128);
                  /// @notice Look up information about a specific tick in the pool
                  /// @param tick The tick to look up
                  /// @return liquidityGross the total amount of position liquidity that uses the pool either as tick lower or
                  /// tick upper,
                  /// liquidityNet how much liquidity changes when the pool price crosses the tick,
                  /// feeGrowthOutside0X128 the fee growth on the other side of the tick from the current tick in token0,
                  /// feeGrowthOutside1X128 the fee growth on the other side of the tick from the current tick in token1,
                  /// tickCumulativeOutside the cumulative tick value on the other side of the tick from the current tick
                  /// secondsPerLiquidityOutsideX128 the seconds spent per liquidity on the other side of the tick from the current tick,
                  /// secondsOutside the seconds spent on the other side of the tick from the current tick,
                  /// initialized Set to true if the tick is initialized, i.e. liquidityGross is greater than 0, otherwise equal to false.
                  /// Outside values can only be used if the tick is initialized, i.e. if liquidityGross is greater than 0.
                  /// In addition, these values are only relative and must be used only in comparison to previous snapshots for
                  /// a specific position.
                  function ticks(int24 tick)
                      external
                      view
                      returns (
                          uint128 liquidityGross,
                          int128 liquidityNet,
                          uint256 feeGrowthOutside0X128,
                          uint256 feeGrowthOutside1X128,
                          int56 tickCumulativeOutside,
                          uint160 secondsPerLiquidityOutsideX128,
                          uint32 secondsOutside,
                          bool initialized
                      );
                  /// @notice Returns 256 packed tick initialized boolean values. See TickBitmap for more information
                  function tickBitmap(int16 wordPosition) external view returns (uint256);
                  /// @notice Returns the information about a position by the position's key
                  /// @param key The position's key is a hash of a preimage composed by the owner, tickLower and tickUpper
                  /// @return _liquidity The amount of liquidity in the position,
                  /// Returns feeGrowthInside0LastX128 fee growth of token0 inside the tick range as of the last mint/burn/poke,
                  /// Returns feeGrowthInside1LastX128 fee growth of token1 inside the tick range as of the last mint/burn/poke,
                  /// Returns tokensOwed0 the computed amount of token0 owed to the position as of the last mint/burn/poke,
                  /// Returns tokensOwed1 the computed amount of token1 owed to the position as of the last mint/burn/poke
                  function positions(bytes32 key)
                      external
                      view
                      returns (
                          uint128 _liquidity,
                          uint256 feeGrowthInside0LastX128,
                          uint256 feeGrowthInside1LastX128,
                          uint128 tokensOwed0,
                          uint128 tokensOwed1
                      );
                  /// @notice Returns data about a specific observation index
                  /// @param index The element of the observations array to fetch
                  /// @dev You most likely want to use #observe() instead of this method to get an observation as of some amount of time
                  /// ago, rather than at a specific index in the array.
                  /// @return blockTimestamp The timestamp of the observation,
                  /// Returns tickCumulative the tick multiplied by seconds elapsed for the life of the pool as of the observation timestamp,
                  /// Returns secondsPerLiquidityCumulativeX128 the seconds per in range liquidity for the life of the pool as of the observation timestamp,
                  /// Returns initialized whether the observation has been initialized and the values are safe to use
                  function observations(uint256 index)
                      external
                      view
                      returns (
                          uint32 blockTimestamp,
                          int56 tickCumulative,
                          uint160 secondsPerLiquidityCumulativeX128,
                          bool initialized
                      );
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Pool state that is not stored
              /// @notice Contains view functions to provide information about the pool that is computed rather than stored on the
              /// blockchain. The functions here may have variable gas costs.
              interface IUniswapV3PoolDerivedState {
                  /// @notice Returns the cumulative tick and liquidity as of each timestamp `secondsAgo` from the current block timestamp
                  /// @dev To get a time weighted average tick or liquidity-in-range, you must call this with two values, one representing
                  /// the beginning of the period and another for the end of the period. E.g., to get the last hour time-weighted average tick,
                  /// you must call it with secondsAgos = [3600, 0].
                  /// @dev The time weighted average tick represents the geometric time weighted average price of the pool, in
                  /// log base sqrt(1.0001) of token1 / token0. The TickMath library can be used to go from a tick value to a ratio.
                  /// @param secondsAgos From how long ago each cumulative tick and liquidity value should be returned
                  /// @return tickCumulatives Cumulative tick values as of each `secondsAgos` from the current block timestamp
                  /// @return secondsPerLiquidityCumulativeX128s Cumulative seconds per liquidity-in-range value as of each `secondsAgos` from the current block
                  /// timestamp
                  function observe(uint32[] calldata secondsAgos)
                      external
                      view
                      returns (int56[] memory tickCumulatives, uint160[] memory secondsPerLiquidityCumulativeX128s);
                  /// @notice Returns a snapshot of the tick cumulative, seconds per liquidity and seconds inside a tick range
                  /// @dev Snapshots must only be compared to other snapshots, taken over a period for which a position existed.
                  /// I.e., snapshots cannot be compared if a position is not held for the entire period between when the first
                  /// snapshot is taken and the second snapshot is taken.
                  /// @param tickLower The lower tick of the range
                  /// @param tickUpper The upper tick of the range
                  /// @return tickCumulativeInside The snapshot of the tick accumulator for the range
                  /// @return secondsPerLiquidityInsideX128 The snapshot of seconds per liquidity for the range
                  /// @return secondsInside The snapshot of seconds per liquidity for the range
                  function snapshotCumulativesInside(int24 tickLower, int24 tickUpper)
                      external
                      view
                      returns (
                          int56 tickCumulativeInside,
                          uint160 secondsPerLiquidityInsideX128,
                          uint32 secondsInside
                      );
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Permissionless pool actions
              /// @notice Contains pool methods that can be called by anyone
              interface IUniswapV3PoolActions {
                  /// @notice Sets the initial price for the pool
                  /// @dev Price is represented as a sqrt(amountToken1/amountToken0) Q64.96 value
                  /// @param sqrtPriceX96 the initial sqrt price of the pool as a Q64.96
                  function initialize(uint160 sqrtPriceX96) external;
                  /// @notice Adds liquidity for the given recipient/tickLower/tickUpper position
                  /// @dev The caller of this method receives a callback in the form of IUniswapV3MintCallback#uniswapV3MintCallback
                  /// in which they must pay any token0 or token1 owed for the liquidity. The amount of token0/token1 due depends
                  /// on tickLower, tickUpper, the amount of liquidity, and the current price.
                  /// @param recipient The address for which the liquidity will be created
                  /// @param tickLower The lower tick of the position in which to add liquidity
                  /// @param tickUpper The upper tick of the position in which to add liquidity
                  /// @param amount The amount of liquidity to mint
                  /// @param data Any data that should be passed through to the callback
                  /// @return amount0 The amount of token0 that was paid to mint the given amount of liquidity. Matches the value in the callback
                  /// @return amount1 The amount of token1 that was paid to mint the given amount of liquidity. Matches the value in the callback
                  function mint(
                      address recipient,
                      int24 tickLower,
                      int24 tickUpper,
                      uint128 amount,
                      bytes calldata data
                  ) external returns (uint256 amount0, uint256 amount1);
                  /// @notice Collects tokens owed to a position
                  /// @dev Does not recompute fees earned, which must be done either via mint or burn of any amount of liquidity.
                  /// Collect must be called by the position owner. To withdraw only token0 or only token1, amount0Requested or
                  /// amount1Requested may be set to zero. To withdraw all tokens owed, caller may pass any value greater than the
                  /// actual tokens owed, e.g. type(uint128).max. Tokens owed may be from accumulated swap fees or burned liquidity.
                  /// @param recipient The address which should receive the fees collected
                  /// @param tickLower The lower tick of the position for which to collect fees
                  /// @param tickUpper The upper tick of the position for which to collect fees
                  /// @param amount0Requested How much token0 should be withdrawn from the fees owed
                  /// @param amount1Requested How much token1 should be withdrawn from the fees owed
                  /// @return amount0 The amount of fees collected in token0
                  /// @return amount1 The amount of fees collected in token1
                  function collect(
                      address recipient,
                      int24 tickLower,
                      int24 tickUpper,
                      uint128 amount0Requested,
                      uint128 amount1Requested
                  ) external returns (uint128 amount0, uint128 amount1);
                  /// @notice Burn liquidity from the sender and account tokens owed for the liquidity to the position
                  /// @dev Can be used to trigger a recalculation of fees owed to a position by calling with an amount of 0
                  /// @dev Fees must be collected separately via a call to #collect
                  /// @param tickLower The lower tick of the position for which to burn liquidity
                  /// @param tickUpper The upper tick of the position for which to burn liquidity
                  /// @param amount How much liquidity to burn
                  /// @return amount0 The amount of token0 sent to the recipient
                  /// @return amount1 The amount of token1 sent to the recipient
                  function burn(
                      int24 tickLower,
                      int24 tickUpper,
                      uint128 amount
                  ) external returns (uint256 amount0, uint256 amount1);
                  /// @notice Swap token0 for token1, or token1 for token0
                  /// @dev The caller of this method receives a callback in the form of IUniswapV3SwapCallback#uniswapV3SwapCallback
                  /// @param recipient The address to receive the output of the swap
                  /// @param zeroForOne The direction of the swap, true for token0 to token1, false for token1 to token0
                  /// @param amountSpecified The amount of the swap, which implicitly configures the swap as exact input (positive), or exact output (negative)
                  /// @param sqrtPriceLimitX96 The Q64.96 sqrt price limit. If zero for one, the price cannot be less than this
                  /// value after the swap. If one for zero, the price cannot be greater than this value after the swap
                  /// @param data Any data to be passed through to the callback
                  /// @return amount0 The delta of the balance of token0 of the pool, exact when negative, minimum when positive
                  /// @return amount1 The delta of the balance of token1 of the pool, exact when negative, minimum when positive
                  function swap(
                      address recipient,
                      bool zeroForOne,
                      int256 amountSpecified,
                      uint160 sqrtPriceLimitX96,
                      bytes calldata data
                  ) external returns (int256 amount0, int256 amount1);
                  /// @notice Receive token0 and/or token1 and pay it back, plus a fee, in the callback
                  /// @dev The caller of this method receives a callback in the form of IUniswapV3FlashCallback#uniswapV3FlashCallback
                  /// @dev Can be used to donate underlying tokens pro-rata to currently in-range liquidity providers by calling
                  /// with 0 amount{0,1} and sending the donation amount(s) from the callback
                  /// @param recipient The address which will receive the token0 and token1 amounts
                  /// @param amount0 The amount of token0 to send
                  /// @param amount1 The amount of token1 to send
                  /// @param data Any data to be passed through to the callback
                  function flash(
                      address recipient,
                      uint256 amount0,
                      uint256 amount1,
                      bytes calldata data
                  ) external;
                  /// @notice Increase the maximum number of price and liquidity observations that this pool will store
                  /// @dev This method is no-op if the pool already has an observationCardinalityNext greater than or equal to
                  /// the input observationCardinalityNext.
                  /// @param observationCardinalityNext The desired minimum number of observations for the pool to store
                  function increaseObservationCardinalityNext(uint16 observationCardinalityNext) external;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Permissioned pool actions
              /// @notice Contains pool methods that may only be called by the factory owner
              interface IUniswapV3PoolOwnerActions {
                  /// @notice Set the denominator of the protocol's % share of the fees
                  /// @param feeProtocol0 new protocol fee for token0 of the pool
                  /// @param feeProtocol1 new protocol fee for token1 of the pool
                  function setFeeProtocol(uint8 feeProtocol0, uint8 feeProtocol1) external;
                  /// @notice Collect the protocol fee accrued to the pool
                  /// @param recipient The address to which collected protocol fees should be sent
                  /// @param amount0Requested The maximum amount of token0 to send, can be 0 to collect fees in only token1
                  /// @param amount1Requested The maximum amount of token1 to send, can be 0 to collect fees in only token0
                  /// @return amount0 The protocol fee collected in token0
                  /// @return amount1 The protocol fee collected in token1
                  function collectProtocol(
                      address recipient,
                      uint128 amount0Requested,
                      uint128 amount1Requested
                  ) external returns (uint128 amount0, uint128 amount1);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Events emitted by a pool
              /// @notice Contains all events emitted by the pool
              interface IUniswapV3PoolEvents {
                  /// @notice Emitted exactly once by a pool when #initialize is first called on the pool
                  /// @dev Mint/Burn/Swap cannot be emitted by the pool before Initialize
                  /// @param sqrtPriceX96 The initial sqrt price of the pool, as a Q64.96
                  /// @param tick The initial tick of the pool, i.e. log base 1.0001 of the starting price of the pool
                  event Initialize(uint160 sqrtPriceX96, int24 tick);
                  /// @notice Emitted when liquidity is minted for a given position
                  /// @param sender The address that minted the liquidity
                  /// @param owner The owner of the position and recipient of any minted liquidity
                  /// @param tickLower The lower tick of the position
                  /// @param tickUpper The upper tick of the position
                  /// @param amount The amount of liquidity minted to the position range
                  /// @param amount0 How much token0 was required for the minted liquidity
                  /// @param amount1 How much token1 was required for the minted liquidity
                  event Mint(
                      address sender,
                      address indexed owner,
                      int24 indexed tickLower,
                      int24 indexed tickUpper,
                      uint128 amount,
                      uint256 amount0,
                      uint256 amount1
                  );
                  /// @notice Emitted when fees are collected by the owner of a position
                  /// @dev Collect events may be emitted with zero amount0 and amount1 when the caller chooses not to collect fees
                  /// @param owner The owner of the position for which fees are collected
                  /// @param tickLower The lower tick of the position
                  /// @param tickUpper The upper tick of the position
                  /// @param amount0 The amount of token0 fees collected
                  /// @param amount1 The amount of token1 fees collected
                  event Collect(
                      address indexed owner,
                      address recipient,
                      int24 indexed tickLower,
                      int24 indexed tickUpper,
                      uint128 amount0,
                      uint128 amount1
                  );
                  /// @notice Emitted when a position's liquidity is removed
                  /// @dev Does not withdraw any fees earned by the liquidity position, which must be withdrawn via #collect
                  /// @param owner The owner of the position for which liquidity is removed
                  /// @param tickLower The lower tick of the position
                  /// @param tickUpper The upper tick of the position
                  /// @param amount The amount of liquidity to remove
                  /// @param amount0 The amount of token0 withdrawn
                  /// @param amount1 The amount of token1 withdrawn
                  event Burn(
                      address indexed owner,
                      int24 indexed tickLower,
                      int24 indexed tickUpper,
                      uint128 amount,
                      uint256 amount0,
                      uint256 amount1
                  );
                  /// @notice Emitted by the pool for any swaps between token0 and token1
                  /// @param sender The address that initiated the swap call, and that received the callback
                  /// @param recipient The address that received the output of the swap
                  /// @param amount0 The delta of the token0 balance of the pool
                  /// @param amount1 The delta of the token1 balance of the pool
                  /// @param sqrtPriceX96 The sqrt(price) of the pool after the swap, as a Q64.96
                  /// @param liquidity The liquidity of the pool after the swap
                  /// @param tick The log base 1.0001 of price of the pool after the swap
                  event Swap(
                      address indexed sender,
                      address indexed recipient,
                      int256 amount0,
                      int256 amount1,
                      uint160 sqrtPriceX96,
                      uint128 liquidity,
                      int24 tick
                  );
                  /// @notice Emitted by the pool for any flashes of token0/token1
                  /// @param sender The address that initiated the swap call, and that received the callback
                  /// @param recipient The address that received the tokens from flash
                  /// @param amount0 The amount of token0 that was flashed
                  /// @param amount1 The amount of token1 that was flashed
                  /// @param paid0 The amount of token0 paid for the flash, which can exceed the amount0 plus the fee
                  /// @param paid1 The amount of token1 paid for the flash, which can exceed the amount1 plus the fee
                  event Flash(
                      address indexed sender,
                      address indexed recipient,
                      uint256 amount0,
                      uint256 amount1,
                      uint256 paid0,
                      uint256 paid1
                  );
                  /// @notice Emitted by the pool for increases to the number of observations that can be stored
                  /// @dev observationCardinalityNext is not the observation cardinality until an observation is written at the index
                  /// just before a mint/swap/burn.
                  /// @param observationCardinalityNextOld The previous value of the next observation cardinality
                  /// @param observationCardinalityNextNew The updated value of the next observation cardinality
                  event IncreaseObservationCardinalityNext(
                      uint16 observationCardinalityNextOld,
                      uint16 observationCardinalityNextNew
                  );
                  /// @notice Emitted when the protocol fee is changed by the pool
                  /// @param feeProtocol0Old The previous value of the token0 protocol fee
                  /// @param feeProtocol1Old The previous value of the token1 protocol fee
                  /// @param feeProtocol0New The updated value of the token0 protocol fee
                  /// @param feeProtocol1New The updated value of the token1 protocol fee
                  event SetFeeProtocol(uint8 feeProtocol0Old, uint8 feeProtocol1Old, uint8 feeProtocol0New, uint8 feeProtocol1New);
                  /// @notice Emitted when the collected protocol fees are withdrawn by the factory owner
                  /// @param sender The address that collects the protocol fees
                  /// @param recipient The address that receives the collected protocol fees
                  /// @param amount0 The amount of token0 protocol fees that is withdrawn
                  /// @param amount0 The amount of token1 protocol fees that is withdrawn
                  event CollectProtocol(address indexed sender, address indexed recipient, uint128 amount0, uint128 amount1);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Callback for IUniswapV3PoolActions#swap
              /// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
              interface IUniswapV3SwapCallback {
                  /// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
                  /// @dev In the implementation you must pay the pool tokens owed for the swap.
                  /// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
                  /// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
                  /// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
                  /// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
                  /// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
                  /// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
                  /// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
                  function uniswapV3SwapCallback(
                      int256 amount0Delta,
                      int256 amount1Delta,
                      bytes calldata data
                  ) external;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Immutable state
              /// @notice Functions that return immutable state of the router
              interface IPeripheryImmutableState {
                  /// @return Returns the address of the Uniswap V3 factory
                  function factory() external view returns (address);
                  /// @return Returns the address of WETH9
                  function WETH9() external view returns (address);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity =0.7.6;
              /// @title Function for getting block timestamp
              /// @dev Base contract that is overridden for tests
              abstract contract BlockTimestamp {
                  /// @dev Method that exists purely to be overridden for tests
                  /// @return The current block timestamp
                  function _blockTimestamp() internal view virtual returns (uint256) {
                      return block.timestamp;
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity ^0.7.0;
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20 {
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `recipient`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address recipient, uint256 amount) external returns (bool);
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
                  /**
                   * @dev Moves `amount` tokens from `sender` to `recipient` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.0;
              /// @title Optimized overflow and underflow safe math operations
              /// @notice Contains methods for doing math operations that revert on overflow or underflow for minimal gas cost
              library LowGasSafeMath {
                  /// @notice Returns x + y, reverts if sum overflows uint256
                  /// @param x The augend
                  /// @param y The addend
                  /// @return z The sum of x and y
                  function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
                      require((z = x + y) >= x);
                  }
                  /// @notice Returns x - y, reverts if underflows
                  /// @param x The minuend
                  /// @param y The subtrahend
                  /// @return z The difference of x and y
                  function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
                      require((z = x - y) <= x);
                  }
                  /// @notice Returns x * y, reverts if overflows
                  /// @param x The multiplicand
                  /// @param y The multiplier
                  /// @return z The product of x and y
                  function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
                      require(x == 0 || (z = x * y) / x == y);
                  }
                  /// @notice Returns x + y, reverts if overflows or underflows
                  /// @param x The augend
                  /// @param y The addend
                  /// @return z The sum of x and y
                  function add(int256 x, int256 y) internal pure returns (int256 z) {
                      require((z = x + y) >= x == (y >= 0));
                  }
                  /// @notice Returns x - y, reverts if overflows or underflows
                  /// @param x The minuend
                  /// @param y The subtrahend
                  /// @return z The difference of x and y
                  function sub(int256 x, int256 y) internal pure returns (int256 z) {
                      require((z = x - y) <= x == (y >= 0));
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
              import '../interfaces/IPeripheryPayments.sol';
              import '../interfaces/external/IWETH9.sol';
              import '../libraries/TransferHelper.sol';
              import './PeripheryImmutableState.sol';
              abstract contract PeripheryPayments is IPeripheryPayments, PeripheryImmutableState {
                  receive() external payable {
                      require(msg.sender == WETH9, 'Not WETH9');
                  }
                  /// @inheritdoc IPeripheryPayments
                  function unwrapWETH9(uint256 amountMinimum, address recipient) external payable override {
                      uint256 balanceWETH9 = IWETH9(WETH9).balanceOf(address(this));
                      require(balanceWETH9 >= amountMinimum, 'Insufficient WETH9');
                      if (balanceWETH9 > 0) {
                          IWETH9(WETH9).withdraw(balanceWETH9);
                          TransferHelper.safeTransferETH(recipient, balanceWETH9);
                      }
                  }
                  /// @inheritdoc IPeripheryPayments
                  function sweepToken(
                      address token,
                      uint256 amountMinimum,
                      address recipient
                  ) external payable override {
                      uint256 balanceToken = IERC20(token).balanceOf(address(this));
                      require(balanceToken >= amountMinimum, 'Insufficient token');
                      if (balanceToken > 0) {
                          TransferHelper.safeTransfer(token, recipient, balanceToken);
                      }
                  }
                  /// @inheritdoc IPeripheryPayments
                  function refundETH() external payable override {
                      if (address(this).balance > 0) TransferHelper.safeTransferETH(msg.sender, address(this).balance);
                  }
                  /// @param token The token to pay
                  /// @param payer The entity that must pay
                  /// @param recipient The entity that will receive payment
                  /// @param value The amount to pay
                  function pay(
                      address token,
                      address payer,
                      address recipient,
                      uint256 value
                  ) internal {
                      if (token == WETH9 && address(this).balance >= value) {
                          // pay with WETH9
                          IWETH9(WETH9).deposit{value: value}(); // wrap only what is needed to pay
                          IWETH9(WETH9).transfer(recipient, value);
                      } else if (payer == address(this)) {
                          // pay with tokens already in the contract (for the exact input multihop case)
                          TransferHelper.safeTransfer(token, recipient, value);
                      } else {
                          // pull payment
                          TransferHelper.safeTransferFrom(token, payer, recipient, value);
                      }
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              import './IPeripheryPayments.sol';
              /// @title Periphery Payments
              /// @notice Functions to ease deposits and withdrawals of ETH
              interface IPeripheryPaymentsWithFee is IPeripheryPayments {
                  /// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH, with a percentage between
                  /// 0 (exclusive), and 1 (inclusive) going to feeRecipient
                  /// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
                  function unwrapWETH9WithFee(
                      uint256 amountMinimum,
                      address recipient,
                      uint256 feeBips,
                      address feeRecipient
                  ) external payable;
                  /// @notice Transfers the full amount of a token held by this contract to recipient, with a percentage between
                  /// 0 (exclusive) and 1 (inclusive) going to feeRecipient
                  /// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
                  function sweepTokenWithFee(
                      address token,
                      uint256 amountMinimum,
                      address recipient,
                      uint256 feeBips,
                      address feeRecipient
                  ) external payable;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.6.0;
              import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
              library TransferHelper {
                  /// @notice Transfers tokens from the targeted address to the given destination
                  /// @notice Errors with 'STF' if transfer fails
                  /// @param token The contract address of the token to be transferred
                  /// @param from The originating address from which the tokens will be transferred
                  /// @param to The destination address of the transfer
                  /// @param value The amount to be transferred
                  function safeTransferFrom(
                      address token,
                      address from,
                      address to,
                      uint256 value
                  ) internal {
                      (bool success, bytes memory data) =
                          token.call(abi.encodeWithSelector(IERC20.transferFrom.selector, from, to, value));
                      require(success && (data.length == 0 || abi.decode(data, (bool))), 'STF');
                  }
                  /// @notice Transfers tokens from msg.sender to a recipient
                  /// @dev Errors with ST if transfer fails
                  /// @param token The contract address of the token which will be transferred
                  /// @param to The recipient of the transfer
                  /// @param value The value of the transfer
                  function safeTransfer(
                      address token,
                      address to,
                      uint256 value
                  ) internal {
                      (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
                      require(success && (data.length == 0 || abi.decode(data, (bool))), 'ST');
                  }
                  /// @notice Approves the stipulated contract to spend the given allowance in the given token
                  /// @dev Errors with 'SA' if transfer fails
                  /// @param token The contract address of the token to be approved
                  /// @param to The target of the approval
                  /// @param value The amount of the given token the target will be allowed to spend
                  function safeApprove(
                      address token,
                      address to,
                      uint256 value
                  ) internal {
                      (bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.approve.selector, to, value));
                      require(success && (data.length == 0 || abi.decode(data, (bool))), 'SA');
                  }
                  /// @notice Transfers ETH to the recipient address
                  /// @dev Fails with `STE`
                  /// @param to The destination of the transfer
                  /// @param value The value to be transferred
                  function safeTransferETH(address to, uint256 value) internal {
                      (bool success, ) = to.call{value: value}(new bytes(0));
                      require(success, 'STE');
                  }
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              /// @title Periphery Payments
              /// @notice Functions to ease deposits and withdrawals of ETH
              interface IPeripheryPayments {
                  /// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH.
                  /// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
                  /// @param amountMinimum The minimum amount of WETH9 to unwrap
                  /// @param recipient The address receiving ETH
                  function unwrapWETH9(uint256 amountMinimum, address recipient) external payable;
                  /// @notice Refunds any ETH balance held by this contract to the `msg.sender`
                  /// @dev Useful for bundling with mint or increase liquidity that uses ether, or exact output swaps
                  /// that use ether for the input amount
                  function refundETH() external payable;
                  /// @notice Transfers the full amount of a token held by this contract to recipient
                  /// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
                  /// @param token The contract address of the token which will be transferred to `recipient`
                  /// @param amountMinimum The minimum amount of token required for a transfer
                  /// @param recipient The destination address of the token
                  function sweepToken(
                      address token,
                      uint256 amountMinimum,
                      address recipient
                  ) external payable;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              pragma abicoder v2;
              /// @title Multicall interface
              /// @notice Enables calling multiple methods in a single call to the contract
              interface IMulticall {
                  /// @notice Call multiple functions in the current contract and return the data from all of them if they all succeed
                  /// @dev The `msg.value` should not be trusted for any method callable from multicall.
                  /// @param data The encoded function data for each of the calls to make to this contract
                  /// @return results The results from each of the calls passed in via data
                  function multicall(bytes[] calldata data) external payable returns (bytes[] memory results);
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /**
               * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
               * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
               *
               * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
               * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't
               * need to send a transaction, and thus is not required to hold Ether at all.
               */
              interface IERC20Permit {
                  /**
                   * @dev Sets `value` as the allowance of `spender` over `owner`'s tokens,
                   * given `owner`'s signed approval.
                   *
                   * IMPORTANT: The same issues {IERC20-approve} has related to transaction
                   * ordering also apply here.
                   *
                   * Emits an {Approval} event.
                   *
                   * Requirements:
                   *
                   * - `spender` cannot be the zero address.
                   * - `deadline` must be a timestamp in the future.
                   * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
                   * over the EIP712-formatted function arguments.
                   * - the signature must use ``owner``'s current nonce (see {nonces}).
                   *
                   * For more information on the signature format, see the
                   * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
                   * section].
                   */
                  function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;
                  /**
                   * @dev Returns the current nonce for `owner`. This value must be
                   * included whenever a signature is generated for {permit}.
                   *
                   * Every successful call to {permit} increases ``owner``'s nonce by one. This
                   * prevents a signature from being used multiple times.
                   */
                  function nonces(address owner) external view returns (uint256);
                  /**
                   * @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.
                   */
                  // solhint-disable-next-line func-name-mixedcase
                  function DOMAIN_SEPARATOR() external view returns (bytes32);
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.7.5;
              /// @title Self Permit
              /// @notice Functionality to call permit on any EIP-2612-compliant token for use in the route
              interface ISelfPermit {
                  /// @notice Permits this contract to spend a given token from `msg.sender`
                  /// @dev The `owner` is always msg.sender and the `spender` is always address(this).
                  /// @param token The address of the token spent
                  /// @param value The amount that can be spent of token
                  /// @param deadline A timestamp, the current blocktime must be less than or equal to this timestamp
                  /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                  /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                  /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                  function selfPermit(
                      address token,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external payable;
                  /// @notice Permits this contract to spend a given token from `msg.sender`
                  /// @dev The `owner` is always msg.sender and the `spender` is always address(this).
                  /// Can be used instead of #selfPermit to prevent calls from failing due to a frontrun of a call to #selfPermit
                  /// @param token The address of the token spent
                  /// @param value The amount that can be spent of token
                  /// @param deadline A timestamp, the current blocktime must be less than or equal to this timestamp
                  /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                  /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                  /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                  function selfPermitIfNecessary(
                      address token,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external payable;
                  /// @notice Permits this contract to spend the sender's tokens for permit signatures that have the `allowed` parameter
                  /// @dev The `owner` is always msg.sender and the `spender` is always address(this)
                  /// @param token The address of the token spent
                  /// @param nonce The current nonce of the owner
                  /// @param expiry The timestamp at which the permit is no longer valid
                  /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                  /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                  /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                  function selfPermitAllowed(
                      address token,
                      uint256 nonce,
                      uint256 expiry,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external payable;
                  /// @notice Permits this contract to spend the sender's tokens for permit signatures that have the `allowed` parameter
                  /// @dev The `owner` is always msg.sender and the `spender` is always address(this)
                  /// Can be used instead of #selfPermitAllowed to prevent calls from failing due to a frontrun of a call to #selfPermitAllowed.
                  /// @param token The address of the token spent
                  /// @param nonce The current nonce of the owner
                  /// @param expiry The timestamp at which the permit is no longer valid
                  /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                  /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                  /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                  function selfPermitAllowedIfNecessary(
                      address token,
                      uint256 nonce,
                      uint256 expiry,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external payable;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              pragma solidity >=0.5.0;
              /// @title Interface for permit
              /// @notice Interface used by DAI/CHAI for permit
              interface IERC20PermitAllowed {
                  /// @notice Approve the spender to spend some tokens via the holder signature
                  /// @dev This is the permit interface used by DAI and CHAI
                  /// @param holder The address of the token holder, the token owner
                  /// @param spender The address of the token spender
                  /// @param nonce The holder's nonce, increases at each call to permit
                  /// @param expiry The timestamp at which the permit is no longer valid
                  /// @param allowed Boolean that sets approval amount, true for type(uint256).max and false for 0
                  /// @param v Must produce valid secp256k1 signature from the holder along with `r` and `s`
                  /// @param r Must produce valid secp256k1 signature from the holder along with `v` and `s`
                  /// @param s Must produce valid secp256k1 signature from the holder along with `r` and `v`
                  function permit(
                      address holder,
                      address spender,
                      uint256 nonce,
                      uint256 expiry,
                      bool allowed,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external;
              }
              // SPDX-License-Identifier: GPL-2.0-or-later
              /*
               * @title Solidity Bytes Arrays Utils
               * @author Gonçalo Sá <[email protected]>
               *
               * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
               *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
               */
              pragma solidity >=0.5.0 <0.8.0;
              library BytesLib {
                  function slice(
                      bytes memory _bytes,
                      uint256 _start,
                      uint256 _length
                  ) internal pure returns (bytes memory) {
                      require(_length + 31 >= _length, 'slice_overflow');
                      require(_start + _length >= _start, 'slice_overflow');
                      require(_bytes.length >= _start + _length, 'slice_outOfBounds');
                      bytes memory tempBytes;
                      assembly {
                          switch iszero(_length)
                              case 0 {
                                  // Get a location of some free memory and store it in tempBytes as
                                  // Solidity does for memory variables.
                                  tempBytes := mload(0x40)
                                  // The first word of the slice result is potentially a partial
                                  // word read from the original array. To read it, we calculate
                                  // the length of that partial word and start copying that many
                                  // bytes into the array. The first word we copy will start with
                                  // data we don't care about, but the last `lengthmod` bytes will
                                  // land at the beginning of the contents of the new array. When
                                  // we're done copying, we overwrite the full first word with
                                  // the actual length of the slice.
                                  let lengthmod := and(_length, 31)
                                  // The multiplication in the next line is necessary
                                  // because when slicing multiples of 32 bytes (lengthmod == 0)
                                  // the following copy loop was copying the origin's length
                                  // and then ending prematurely not copying everything it should.
                                  let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                                  let end := add(mc, _length)
                                  for {
                                      // The multiplication in the next line has the same exact purpose
                                      // as the one above.
                                      let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                                  } lt(mc, end) {
                                      mc := add(mc, 0x20)
                                      cc := add(cc, 0x20)
                                  } {
                                      mstore(mc, mload(cc))
                                  }
                                  mstore(tempBytes, _length)
                                  //update free-memory pointer
                                  //allocating the array padded to 32 bytes like the compiler does now
                                  mstore(0x40, and(add(mc, 31), not(31)))
                              }
                              //if we want a zero-length slice let's just return a zero-length array
                              default {
                                  tempBytes := mload(0x40)
                                  //zero out the 32 bytes slice we are about to return
                                  //we need to do it because Solidity does not garbage collect
                                  mstore(tempBytes, 0)
                                  mstore(0x40, add(tempBytes, 0x20))
                              }
                      }
                      return tempBytes;
                  }
                  function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                      require(_start + 20 >= _start, 'toAddress_overflow');
                      require(_bytes.length >= _start + 20, 'toAddress_outOfBounds');
                      address tempAddress;
                      assembly {
                          tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                      }
                      return tempAddress;
                  }
                  function toUint24(bytes memory _bytes, uint256 _start) internal pure returns (uint24) {
                      require(_start + 3 >= _start, 'toUint24_overflow');
                      require(_bytes.length >= _start + 3, 'toUint24_outOfBounds');
                      uint24 tempUint;
                      assembly {
                          tempUint := mload(add(add(_bytes, 0x3), _start))
                      }
                      return tempUint;
                  }
              }
              

              File 2 of 4: RibbonToken
              // SPDX-License-Identifier: GPL-3.0
              pragma solidity ^0.8.0;
              
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20 {
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
              
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
              
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `recipient`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address recipient, uint256 amount) external returns (bool);
              
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
              
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
              
                  /**
                   * @dev Moves `amount` tokens from `sender` to `recipient` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
              
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
              
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
              }
              
              interface IERC20Metadata is IERC20 {
                  /**
                   * @dev Returns the name of the token.
                   */
                  function name() external view returns (string memory);
              
                  /**
                   * @dev Returns the symbol of the token.
                   */
                  function symbol() external view returns (string memory);
              
                  /**
                   * @dev Returns the decimals places of the token.
                   */
                  function decimals() external view returns (uint8);
              }
              
              
              /*
               * @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 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.
               */
              abstract contract Context {
                  function _msgSender() internal view virtual returns (address) {
                      return msg.sender;
                  }
              
                  function _msgData() internal view virtual returns (bytes calldata) {
                      this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                      return msg.data;
                  }
              }
              
              /**
               * @dev Implementation of the {IERC20} interface.
               *
               * This implementation is agnostic to the way tokens are created. This means
               * that a supply mechanism has to be added in a derived contract using {_mint}.
               * For a generic mechanism see {ERC20PresetMinterPauser}.
               *
               * TIP: For a detailed writeup see our guide
               * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
               * to implement supply mechanisms].
               *
               * We have followed general OpenZeppelin guidelines: functions revert instead
               * of returning `false` on failure. This behavior is nonetheless conventional
               * and does not conflict with the expectations of ERC20 applications.
               *
               * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
               * This allows applications to reconstruct the allowance for all accounts just
               * by listening to said events. Other implementations of the EIP may not emit
               * these events, as it isn't required by the specification.
               *
               * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
               * functions have been added to mitigate the well-known issues around setting
               * allowances. See {IERC20-approve}.
               */
              contract ERC20 is Context, IERC20, IERC20Metadata {
                  mapping (address => uint256) private _balances;
              
                  mapping (address => mapping (address => uint256)) private _allowances;
              
                  uint256 private _totalSupply;
              
                  string private _name;
                  string private _symbol;
              
                  /**
                   * @dev Sets the values for {name} and {symbol}.
                   *
                   * The defaut value of {decimals} is 18. To select a different value for
                   * {decimals} you should overload it.
                   *
                   * All two of these values are immutable: they can only be set once during
                   * construction.
                   */
                  constructor (string memory name_, string memory symbol_) {
                      _name = name_;
                      _symbol = symbol_;
                  }
              
                  /**
                   * @dev Returns the name of the token.
                   */
                  function name() public view virtual override returns (string memory) {
                      return _name;
                  }
              
                  /**
                   * @dev Returns the symbol of the token, usually a shorter version of the
                   * name.
                   */
                  function symbol() public view virtual override returns (string memory) {
                      return _symbol;
                  }
              
                  /**
                   * @dev Returns the number of decimals used to get its user representation.
                   * For example, if `decimals` equals `2`, a balance of `505` tokens should
                   * be displayed to a user as `5,05` (`505 / 10 ** 2`).
                   *
                   * Tokens usually opt for a value of 18, imitating the relationship between
                   * Ether and Wei. This is the value {ERC20} uses, unless this function is
                   * overridden;
                   *
                   * NOTE: This information is only used for _display_ purposes: it in
                   * no way affects any of the arithmetic of the contract, including
                   * {IERC20-balanceOf} and {IERC20-transfer}.
                   */
                  function decimals() public view virtual override returns (uint8) {
                      return 18;
                  }
              
                  /**
                   * @dev See {IERC20-totalSupply}.
                   */
                  function totalSupply() public view virtual override returns (uint256) {
                      return _totalSupply;
                  }
              
                  /**
                   * @dev See {IERC20-balanceOf}.
                   */
                  function balanceOf(address account) public view virtual override returns (uint256) {
                      return _balances[account];
                  }
              
                  /**
                   * @dev See {IERC20-transfer}.
                   *
                   * Requirements:
                   *
                   * - `recipient` cannot be the zero address.
                   * - the caller must have a balance of at least `amount`.
                   */
                  function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
                      _transfer(_msgSender(), recipient, amount);
                      return true;
                  }
              
                  /**
                   * @dev See {IERC20-allowance}.
                   */
                  function allowance(address owner, address spender) public view virtual override returns (uint256) {
                      return _allowances[owner][spender];
                  }
              
                  /**
                   * @dev See {IERC20-approve}.
                   *
                   * Requirements:
                   *
                   * - `spender` cannot be the zero address.
                   */
                  function approve(address spender, uint256 amount) public virtual override returns (bool) {
                      _approve(_msgSender(), spender, amount);
                      return true;
                  }
              
                  /**
                   * @dev See {IERC20-transferFrom}.
                   *
                   * Emits an {Approval} event indicating the updated allowance. This is not
                   * required by the EIP. See the note at the beginning of {ERC20}.
                   *
                   * Requirements:
                   *
                   * - `sender` and `recipient` cannot be the zero address.
                   * - `sender` must have a balance of at least `amount`.
                   * - the caller must have allowance for ``sender``'s tokens of at least
                   * `amount`.
                   */
                  function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
                      _transfer(sender, recipient, amount);
              
                      uint256 currentAllowance = _allowances[sender][_msgSender()];
                      require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
                      _approve(sender, _msgSender(), currentAllowance - amount);
              
                      return true;
                  }
              
                  /**
                   * @dev Atomically increases the allowance granted to `spender` by the caller.
                   *
                   * This is an alternative to {approve} that can be used as a mitigation for
                   * problems described in {IERC20-approve}.
                   *
                   * Emits an {Approval} event indicating the updated allowance.
                   *
                   * Requirements:
                   *
                   * - `spender` cannot be the zero address.
                   */
                  function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
                      _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
                      return true;
                  }
              
                  /**
                   * @dev Atomically decreases the allowance granted to `spender` by the caller.
                   *
                   * This is an alternative to {approve} that can be used as a mitigation for
                   * problems described in {IERC20-approve}.
                   *
                   * Emits an {Approval} event indicating the updated allowance.
                   *
                   * Requirements:
                   *
                   * - `spender` cannot be the zero address.
                   * - `spender` must have allowance for the caller of at least
                   * `subtractedValue`.
                   */
                  function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
                      uint256 currentAllowance = _allowances[_msgSender()][spender];
                      require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
                      _approve(_msgSender(), spender, currentAllowance - subtractedValue);
              
                      return true;
                  }
              
                  /**
                   * @dev Moves tokens `amount` from `sender` to `recipient`.
                   *
                   * This is internal function is equivalent to {transfer}, and can be used to
                   * e.g. implement automatic token fees, slashing mechanisms, etc.
                   *
                   * Emits a {Transfer} event.
                   *
                   * Requirements:
                   *
                   * - `sender` cannot be the zero address.
                   * - `recipient` cannot be the zero address.
                   * - `sender` must have a balance of at least `amount`.
                   */
                  function _transfer(address sender, address recipient, uint256 amount) internal virtual {
                      require(sender != address(0), "ERC20: transfer from the zero address");
                      require(recipient != address(0), "ERC20: transfer to the zero address");
              
                      _beforeTokenTransfer(sender, recipient, amount);
              
                      uint256 senderBalance = _balances[sender];
                      require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
                      _balances[sender] = senderBalance - amount;
                      _balances[recipient] += amount;
              
                      emit Transfer(sender, recipient, amount);
                  }
              
                  /** @dev Creates `amount` tokens and assigns them to `account`, increasing
                   * the total supply.
                   *
                   * Emits a {Transfer} event with `from` set to the zero address.
                   *
                   * Requirements:
                   *
                   * - `to` cannot be the zero address.
                   */
                  function _mint(address account, uint256 amount) internal virtual {
                      require(account != address(0), "ERC20: mint to the zero address");
              
                      _beforeTokenTransfer(address(0), account, amount);
              
                      _totalSupply += amount;
                      _balances[account] += amount;
                      emit Transfer(address(0), account, amount);
                  }
              
                  /**
                   * @dev Destroys `amount` tokens from `account`, reducing the
                   * total supply.
                   *
                   * Emits a {Transfer} event with `to` set to the zero address.
                   *
                   * Requirements:
                   *
                   * - `account` cannot be the zero address.
                   * - `account` must have at least `amount` tokens.
                   */
                  function _burn(address account, uint256 amount) internal virtual {
                      require(account != address(0), "ERC20: burn from the zero address");
              
                      _beforeTokenTransfer(account, address(0), amount);
              
                      uint256 accountBalance = _balances[account];
                      require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
                      _balances[account] = accountBalance - amount;
                      _totalSupply -= amount;
              
                      emit Transfer(account, address(0), amount);
                  }
              
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
                   *
                   * This internal function is equivalent to `approve`, and can be used to
                   * e.g. set automatic allowances for certain subsystems, etc.
                   *
                   * Emits an {Approval} event.
                   *
                   * Requirements:
                   *
                   * - `owner` cannot be the zero address.
                   * - `spender` cannot be the zero address.
                   */
                  function _approve(address owner, address spender, uint256 amount) internal virtual {
                      require(owner != address(0), "ERC20: approve from the zero address");
                      require(spender != address(0), "ERC20: approve to the zero address");
              
                      _allowances[owner][spender] = amount;
                      emit Approval(owner, spender, amount);
                  }
              
                  /**
                   * @dev Hook that is called before any transfer of tokens. This includes
                   * minting and burning.
                   *
                   * Calling conditions:
                   *
                   * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
                   * will be to transferred to `to`.
                   * - when `from` is zero, `amount` tokens will be minted for `to`.
                   * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
                   * - `from` and `to` are never both zero.
                   *
                   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
                   */
                  function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
              }
              
              
              /**
               * @dev String operations.
               */
              library Strings {
                  bytes16 private constant alphabet = "0123456789abcdef";
              
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` decimal representation.
                   */
                  function toString(uint256 value) internal pure returns (string memory) {
                      // Inspired by OraclizeAPI's implementation - MIT licence
                      // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
              
                      if (value == 0) {
                          return "0";
                      }
                      uint256 temp = value;
                      uint256 digits;
                      while (temp != 0) {
                          digits++;
                          temp /= 10;
                      }
                      bytes memory buffer = new bytes(digits);
                      while (value != 0) {
                          digits -= 1;
                          buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                          value /= 10;
                      }
                      return string(buffer);
                  }
              
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
                   */
                  function toHexString(uint256 value) internal pure returns (string memory) {
                      if (value == 0) {
                          return "0x00";
                      }
                      uint256 temp = value;
                      uint256 length = 0;
                      while (temp != 0) {
                          length++;
                          temp >>= 8;
                      }
                      return toHexString(value, length);
                  }
              
                  /**
                   * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
                   */
                  function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                      bytes memory buffer = new bytes(2 * length + 2);
                      buffer[0] = "0";
                      buffer[1] = "x";
                      for (uint256 i = 2 * length + 1; i > 1; --i) {
                          buffer[i] = alphabet[value & 0xf];
                          value >>= 4;
                      }
                      require(value == 0, "Strings: hex length insufficient");
                      return string(buffer);
                  }
              
              }
              
              
              
              /**
               * @dev External interface of AccessControl declared to support ERC165 detection.
               */
              interface IAccessControl {
                  function hasRole(bytes32 role, address account) external view returns (bool);
                  function getRoleAdmin(bytes32 role) external view returns (bytes32);
                  function grantRole(bytes32 role, address account) external;
                  function revokeRole(bytes32 role, address account) external;
                  function renounceRole(bytes32 role, address account) external;
              }
              
              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);
              }
              
              
              abstract contract ERC165 is IERC165 {
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IERC165).interfaceId;
                  }
              }
              
              /**
               * @dev Contract module that allows children to implement role-based access
               * control mechanisms. This is a lightweight version that doesn't allow enumerating role
               * members except through off-chain means by accessing the contract event logs. Some
               * applications may benefit from on-chain enumerability, for those cases see
               * {AccessControlEnumerable}.
               *
               * Roles are referred to by their `bytes32` identifier. These should be exposed
               * in the external API and be unique. The best way to achieve this is by
               * using `public constant` hash digests:
               *
               * ```
               * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
               * ```
               *
               * Roles can be used to represent a set of permissions. To restrict access to a
               * function call, use {hasRole}:
               *
               * ```
               * function foo() public {
               *     require(hasRole(MY_ROLE, msg.sender));
               *     ...
               * }
               * ```
               *
               * Roles can be granted and revoked dynamically via the {grantRole} and
               * {revokeRole} functions. Each role has an associated admin role, and only
               * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
               *
               * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
               * that only accounts with this role will be able to grant or revoke other
               * roles. More complex role relationships can be created by using
               * {_setRoleAdmin}.
               *
               * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
               * grant and revoke this role. Extra precautions should be taken to secure
               * accounts that have been granted it.
               */
              abstract contract AccessControl is Context, IAccessControl, ERC165 {
                  struct RoleData {
                      mapping (address => bool) members;
                      bytes32 adminRole;
                  }
              
                  mapping (bytes32 => RoleData) private _roles;
              
                  bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
              
                  /**
                   * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
                   *
                   * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
                   * {RoleAdminChanged} not being emitted signaling this.
                   *
                   * _Available since v3.1._
                   */
                  event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
              
                  /**
                   * @dev Emitted when `account` is granted `role`.
                   *
                   * `sender` is the account that originated the contract call, an admin role
                   * bearer except when using {_setupRole}.
                   */
                  event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
              
                  /**
                   * @dev Emitted when `account` is revoked `role`.
                   *
                   * `sender` is the account that originated the contract call:
                   *   - if using `revokeRole`, it is the admin role bearer
                   *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
                   */
                  event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
              
                  /**
                   * @dev Modifier that checks that an account has a specific role. Reverts
                   * with a standardized message including the required role.
                   *
                   * The format of the revert reason is given by the following regular expression:
                   *
                   *  /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/
                   *
                   * _Available since v4.1._
                   */
                  modifier onlyRole(bytes32 role) {
                      _checkRole(role, _msgSender());
                      _;
                  }
              
                  /**
                   * @dev See {IERC165-supportsInterface}.
                   */
                  function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                      return interfaceId == type(IAccessControl).interfaceId
                          || super.supportsInterface(interfaceId);
                  }
              
                  /**
                   * @dev Returns `true` if `account` has been granted `role`.
                   */
                  function hasRole(bytes32 role, address account) public view override returns (bool) {
                      return _roles[role].members[account];
                  }
              
                  /**
                   * @dev Revert with a standard message if `account` is missing `role`.
                   *
                   * The format of the revert reason is given by the following regular expression:
                   *
                   *  /^AccessControl: account (0x[0-9a-f]{20}) is missing role (0x[0-9a-f]{32})$/
                   */
                  function _checkRole(bytes32 role, address account) internal view {
                      if(!hasRole(role, account)) {
                          revert(string(abi.encodePacked(
                              "AccessControl: account ",
                              Strings.toHexString(uint160(account), 20),
                              " is missing role ",
                              Strings.toHexString(uint256(role), 32)
                          )));
                      }
                  }
              
                  /**
                   * @dev Returns the admin role that controls `role`. See {grantRole} and
                   * {revokeRole}.
                   *
                   * To change a role's admin, use {_setRoleAdmin}.
                   */
                  function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
                      return _roles[role].adminRole;
                  }
              
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                      _grantRole(role, account);
                  }
              
                  /**
                   * @dev Revokes `role` from `account`.
                   *
                   * If `account` had been granted `role`, emits a {RoleRevoked} event.
                   *
                   * Requirements:
                   *
                   * - the caller must have ``role``'s admin role.
                   */
                  function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                      _revokeRole(role, account);
                  }
              
                  /**
                   * @dev Revokes `role` from the calling account.
                   *
                   * Roles are often managed via {grantRole} and {revokeRole}: this function's
                   * purpose is to provide a mechanism for accounts to lose their privileges
                   * if they are compromised (such as when a trusted device is misplaced).
                   *
                   * If the calling account had been granted `role`, emits a {RoleRevoked}
                   * event.
                   *
                   * Requirements:
                   *
                   * - the caller must be `account`.
                   */
                  function renounceRole(bytes32 role, address account) public virtual override {
                      require(account == _msgSender(), "AccessControl: can only renounce roles for self");
              
                      _revokeRole(role, account);
                  }
              
                  /**
                   * @dev Grants `role` to `account`.
                   *
                   * If `account` had not been already granted `role`, emits a {RoleGranted}
                   * event. Note that unlike {grantRole}, this function doesn't perform any
                   * checks on the calling account.
                   *
                   * [WARNING]
                   * ====
                   * This function should only be called from the constructor when setting
                   * up the initial roles for the system.
                   *
                   * Using this function in any other way is effectively circumventing the admin
                   * system imposed by {AccessControl}.
                   * ====
                   */
                  function _setupRole(bytes32 role, address account) internal virtual {
                      _grantRole(role, account);
                  }
              
                  /**
                   * @dev Sets `adminRole` as ``role``'s admin role.
                   *
                   * Emits a {RoleAdminChanged} event.
                   */
                  function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                      emit RoleAdminChanged(role, getRoleAdmin(role), adminRole);
                      _roles[role].adminRole = adminRole;
                  }
              
                  function _grantRole(bytes32 role, address account) private {
                      if (!hasRole(role, account)) {
                          _roles[role].members[account] = true;
                          emit RoleGranted(role, account, _msgSender());
                      }
                  }
              
                  function _revokeRole(bytes32 role, address account) private {
                      if (hasRole(role, account)) {
                          _roles[role].members[account] = false;
                          emit RoleRevoked(role, account, _msgSender());
                      }
                  }
              }
              
              
              
              /**
               * RIBBON FINANCE: STRUCTURED PRODUCTS FOR THE PEOPLE
               */
              contract RibbonToken is AccessControl, ERC20 {
                  /// @dev The identifier of the role which maintains other roles.
                  bytes32 public constant ADMIN_ROLE = keccak256("ADMIN");
                  /// @dev The identifier of the role which allows accounts to mint tokens.
                  bytes32 public constant MINTER_ROLE = keccak256("MINTER");
                  /// @dev The identifier of the role which allows special transfer privileges.
                  bytes32 public constant TRANSFER_ROLE = keccak256("TRANSFER");
              
                  /// @dev bool flag of whether transfer is currently allowed for all people.
                  bool public transfersAllowed = false;
              
                  constructor(
                      string memory name,
                      string memory symbol,
                      uint256 totalSupply,
                      address beneficiary
                  ) ERC20(name, symbol) {
                      // We are minting initialSupply number of tokens
                      _mint(beneficiary, totalSupply);
                      // Add beneficiary as minter
                      _setupRole(MINTER_ROLE, beneficiary);
                      // Add beneficiary as transferer
                      _setupRole(TRANSFER_ROLE, beneficiary);
                      // Add beneficiary as admin
                      _setupRole(ADMIN_ROLE, beneficiary);
                      // Set ADMIN role as admin of transfer role
                      _setRoleAdmin(TRANSFER_ROLE, ADMIN_ROLE);
                  }
              
                  /// @dev A modifier which checks that the caller has the minter role.
                  modifier onlyMinter() {
                      require(hasRole(MINTER_ROLE, msg.sender), "RibbonToken: only minter");
                      _;
                  }
              
                  /// @dev A modifier which checks that the caller has the admin role.
                  modifier onlyAdmin() {
                      require(hasRole(ADMIN_ROLE, msg.sender), "RibbonToken: only admin");
                      _;
                  }
              
                  /// @dev A modifier which checks that the caller has transfer privileges.
                  modifier onlyTransferer(address from) {
                      require(
                          transfersAllowed ||
                              from == address(0) ||
                              hasRole(TRANSFER_ROLE, msg.sender),
                          "RibbonToken: no transfer privileges"
                      );
                      _;
                  }
              
                  /// @dev Mints tokens to a recipient.
                  ///
                  /// This function reverts if the caller does not have the minter role.
                  function mint(address _recipient, uint256 _amount) external onlyMinter {
                      _mint(_recipient, _amount);
                  }
              
                  /// @dev Toggles transfer allowed flag.
                  ///
                  /// This function reverts if the caller does not have the admin role.
                  function setTransfersAllowed(bool _transfersAllowed) external onlyAdmin {
                      transfersAllowed = _transfersAllowed;
                      emit TransfersAllowed(transfersAllowed);
                  }
              
                  /// @dev Hook that is called before any transfer of tokens.
                  function _beforeTokenTransfer(
                      address from,
                      address to,
                      uint256 amount
                  ) internal virtual override onlyTransferer(from) {}
              
                  /// @dev Emitted when transfer toggle is switched
                  event TransfersAllowed(bool transfersAllowed);
              }

              File 3 of 4: FiatTokenProxy
              pragma solidity ^0.4.24;
              
              // File: zos-lib/contracts/upgradeability/Proxy.sol
              
              /**
               * @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-solidity/contracts/AddressUtils.sol
              
              /**
               * Utility library of inline functions on addresses
               */
              library AddressUtils {
              
                /**
                 * 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 addr address to check
                 * @return whether the target address is a contract
                 */
                function isContract(address addr) 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.
                  // solium-disable-next-line security/no-inline-assembly
                  assembly { size := extcodesize(addr) }
                  return size > 0;
                }
              
              }
              
              // File: zos-lib/contracts/upgradeability/UpgradeabilityProxy.sol
              
              /**
               * @title UpgradeabilityProxy
               * @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 UpgradeabilityProxy is Proxy {
                /**
                 * @dev Emitted when the implementation is upgraded.
                 * @param implementation Address of the new implementation.
                 */
                event Upgraded(address implementation);
              
                /**
                 * @dev Storage slot with the address of the current implementation.
                 * This is the keccak-256 hash of "org.zeppelinos.proxy.implementation", and is
                 * validated in the constructor.
                 */
                bytes32 private constant IMPLEMENTATION_SLOT = 0x7050c9e0f4ca769c69bd3a8ef740bc37934f8e2c036e5a723fd8ee048ed3f8c3;
              
                /**
                 * @dev Contract constructor.
                 * @param _implementation Address of the initial implementation.
                 */
                constructor(address _implementation) public {
                  assert(IMPLEMENTATION_SLOT == keccak256("org.zeppelinos.proxy.implementation"));
              
                  _setImplementation(_implementation);
                }
              
                /**
                 * @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) private {
                  require(AddressUtils.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
              
                  bytes32 slot = IMPLEMENTATION_SLOT;
              
                  assembly {
                    sstore(slot, newImplementation)
                  }
                }
              }
              
              // File: zos-lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
              
              /**
               * @title AdminUpgradeabilityProxy
               * @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 AdminUpgradeabilityProxy is UpgradeabilityProxy {
                /**
                 * @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 "org.zeppelinos.proxy.admin", and is
                 * validated in the constructor.
                 */
                bytes32 private constant ADMIN_SLOT = 0x10d6a54a4754c8869d6886b5f5d7fbfa5b4522237ea5c60d11bc4e7a1ff9390b;
              
                /**
                 * @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();
                  }
                }
              
                /**
                 * Contract constructor.
                 * It sets the `msg.sender` as the proxy administrator.
                 * @param _implementation address of the initial implementation.
                 */
                constructor(address _implementation) UpgradeabilityProxy(_implementation) public {
                  assert(ADMIN_SLOT == keccak256("org.zeppelinos.proxy.admin"));
              
                  _setAdmin(msg.sender);
                }
              
                /**
                 * @return The address of the proxy admin.
                 */
                function admin() external view ifAdmin returns (address) {
                  return _admin();
                }
              
                /**
                 * @return The address of the implementation.
                 */
                function implementation() external view 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/develop/abi-spec.html#function-selector-and-argument-encoding.
                 */
                function upgradeToAndCall(address newImplementation, bytes data) payable external ifAdmin {
                  _upgradeTo(newImplementation);
                  require(address(this).call.value(msg.value)(data));
                }
              
                /**
                 * @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: contracts/FiatTokenProxy.sol
              
              /**
              * Copyright CENTRE SECZ 2018
              *
              * Permission is hereby granted, free of charge, to any person obtaining a copy 
              * of this software and associated documentation files (the "Software"), to deal 
              * in the Software without restriction, including without limitation the rights 
              * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
              * copies of the Software, and to permit persons to whom the Software is furnished to 
              * do so, subject to the following conditions:
              *
              * The above copyright notice and this permission notice shall be included in all 
              * copies or substantial portions of the Software.
              *
              * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
              * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
              * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
              * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
              * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
              * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
              */
              
              pragma solidity ^0.4.24;
              
              
              /**
               * @title FiatTokenProxy
               * @dev This contract proxies FiatToken calls and enables FiatToken upgrades
              */ 
              contract FiatTokenProxy is AdminUpgradeabilityProxy {
                  constructor(address _implementation) public AdminUpgradeabilityProxy(_implementation) {
                  }
              }

              File 4 of 4: FiatTokenV2_2
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { EIP712Domain } from "./EIP712Domain.sol"; // solhint-disable-line no-unused-import
              import { Blacklistable } from "../v1/Blacklistable.sol"; // solhint-disable-line no-unused-import
              import { FiatTokenV1 } from "../v1/FiatTokenV1.sol"; // solhint-disable-line no-unused-import
              import { FiatTokenV2 } from "./FiatTokenV2.sol"; // solhint-disable-line no-unused-import
              import { FiatTokenV2_1 } from "./FiatTokenV2_1.sol";
              import { EIP712 } from "../util/EIP712.sol";
              // solhint-disable func-name-mixedcase
              /**
               * @title FiatToken V2.2
               * @notice ERC20 Token backed by fiat reserves, version 2.2
               */
              contract FiatTokenV2_2 is FiatTokenV2_1 {
                  /**
                   * @notice Initialize v2.2
                   * @param accountsToBlacklist   A list of accounts to migrate from the old blacklist
                   * @param newSymbol             New token symbol
                   * data structure to the new blacklist data structure.
                   */
                  function initializeV2_2(
                      address[] calldata accountsToBlacklist,
                      string calldata newSymbol
                  ) external {
                      // solhint-disable-next-line reason-string
                      require(_initializedVersion == 2);
                      // Update fiat token symbol
                      symbol = newSymbol;
                      // Add previously blacklisted accounts to the new blacklist data structure
                      // and remove them from the old blacklist data structure.
                      for (uint256 i = 0; i < accountsToBlacklist.length; i++) {
                          require(
                              _deprecatedBlacklisted[accountsToBlacklist[i]],
                              "FiatTokenV2_2: Blacklisting previously unblacklisted account!"
                          );
                          _blacklist(accountsToBlacklist[i]);
                          delete _deprecatedBlacklisted[accountsToBlacklist[i]];
                      }
                      _blacklist(address(this));
                      delete _deprecatedBlacklisted[address(this)];
                      _initializedVersion = 3;
                  }
                  /**
                   * @dev Internal function to get the current chain id.
                   * @return The current chain id.
                   */
                  function _chainId() internal virtual view returns (uint256) {
                      uint256 chainId;
                      assembly {
                          chainId := chainid()
                      }
                      return chainId;
                  }
                  /**
                   * @inheritdoc EIP712Domain
                   */
                  function _domainSeparator() internal override view returns (bytes32) {
                      return EIP712.makeDomainSeparator(name, "2", _chainId());
                  }
                  /**
                   * @notice Update allowance with a signed permit
                   * @dev EOA wallet signatures should be packed in the order of r, s, v.
                   * @param owner       Token owner's address (Authorizer)
                   * @param spender     Spender's address
                   * @param value       Amount of allowance
                   * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                   * @param signature   Signature bytes signed by an EOA wallet or a contract wallet
                   */
                  function permit(
                      address owner,
                      address spender,
                      uint256 value,
                      uint256 deadline,
                      bytes memory signature
                  ) external whenNotPaused {
                      _permit(owner, spender, value, deadline, signature);
                  }
                  /**
                   * @notice Execute a transfer with a signed authorization
                   * @dev EOA wallet signatures should be packed in the order of r, s, v.
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                   */
                  function transferWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      bytes memory signature
                  ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                      _transferWithAuthorization(
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce,
                          signature
                      );
                  }
                  /**
                   * @notice Receive a transfer with a signed authorization from the payer
                   * @dev This has an additional check to ensure that the payee's address
                   * matches the caller of this function to prevent front-running attacks.
                   * EOA wallet signatures should be packed in the order of r, s, v.
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                   */
                  function receiveWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      bytes memory signature
                  ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                      _receiveWithAuthorization(
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce,
                          signature
                      );
                  }
                  /**
                   * @notice Attempt to cancel an authorization
                   * @dev Works only if the authorization is not yet used.
                   * EOA wallet signatures should be packed in the order of r, s, v.
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   * @param signature     Signature bytes signed by an EOA wallet or a contract wallet
                   */
                  function cancelAuthorization(
                      address authorizer,
                      bytes32 nonce,
                      bytes memory signature
                  ) external whenNotPaused {
                      _cancelAuthorization(authorizer, nonce, signature);
                  }
                  /**
                   * @dev Helper method that sets the blacklist state of an account on balanceAndBlacklistStates.
                   * If _shouldBlacklist is true, we apply a (1 << 255) bitmask with an OR operation on the
                   * account's balanceAndBlacklistState. This flips the high bit for the account to 1,
                   * indicating that the account is blacklisted.
                   *
                   * If _shouldBlacklist if false, we reset the account's balanceAndBlacklistStates to their
                   * balances. This clears the high bit for the account, indicating that the account is unblacklisted.
                   * @param _account         The address of the account.
                   * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
                   */
                  function _setBlacklistState(address _account, bool _shouldBlacklist)
                      internal
                      override
                  {
                      balanceAndBlacklistStates[_account] = _shouldBlacklist
                          ? balanceAndBlacklistStates[_account] | (1 << 255)
                          : _balanceOf(_account);
                  }
                  /**
                   * @dev Helper method that sets the balance of an account on balanceAndBlacklistStates.
                   * Since balances are stored in the last 255 bits of the balanceAndBlacklistStates value,
                   * we need to ensure that the updated balance does not exceed (2^255 - 1).
                   * Since blacklisted accounts' balances cannot be updated, the method will also
                   * revert if the account is blacklisted
                   * @param _account The address of the account.
                   * @param _balance The new fiat token balance of the account (max: (2^255 - 1)).
                   */
                  function _setBalance(address _account, uint256 _balance) internal override {
                      require(
                          _balance <= ((1 << 255) - 1),
                          "FiatTokenV2_2: Balance exceeds (2^255 - 1)"
                      );
                      require(
                          !_isBlacklisted(_account),
                          "FiatTokenV2_2: Account is blacklisted"
                      );
                      balanceAndBlacklistStates[_account] = _balance;
                  }
                  /**
                   * @inheritdoc Blacklistable
                   */
                  function _isBlacklisted(address _account)
                      internal
                      override
                      view
                      returns (bool)
                  {
                      return balanceAndBlacklistStates[_account] >> 255 == 1;
                  }
                  /**
                   * @dev Helper method to obtain the balance of an account. Since balances
                   * are stored in the last 255 bits of the balanceAndBlacklistStates value,
                   * we apply a ((1 << 255) - 1) bit bitmask with an AND operation on the
                   * balanceAndBlacklistState to obtain the balance.
                   * @param _account  The address of the account.
                   * @return          The fiat token balance of the account.
                   */
                  function _balanceOf(address _account)
                      internal
                      override
                      view
                      returns (uint256)
                  {
                      return balanceAndBlacklistStates[_account] & ((1 << 255) - 1);
                  }
                  /**
                   * @inheritdoc FiatTokenV1
                   */
                  function approve(address spender, uint256 value)
                      external
                      override
                      whenNotPaused
                      returns (bool)
                  {
                      _approve(msg.sender, spender, value);
                      return true;
                  }
                  /**
                   * @inheritdoc FiatTokenV2
                   */
                  function permit(
                      address owner,
                      address spender,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external override whenNotPaused {
                      _permit(owner, spender, value, deadline, v, r, s);
                  }
                  /**
                   * @inheritdoc FiatTokenV2
                   */
                  function increaseAllowance(address spender, uint256 increment)
                      external
                      override
                      whenNotPaused
                      returns (bool)
                  {
                      _increaseAllowance(msg.sender, spender, increment);
                      return true;
                  }
                  /**
                   * @inheritdoc FiatTokenV2
                   */
                  function decreaseAllowance(address spender, uint256 decrement)
                      external
                      override
                      whenNotPaused
                      returns (bool)
                  {
                      _decreaseAllowance(msg.sender, spender, decrement);
                      return true;
                  }
              }
              // 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);
                          }
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              import "./IERC20.sol";
              import "../../math/SafeMath.sol";
              import "../../utils/Address.sol";
              /**
               * @title SafeERC20
               * @dev Wrappers around ERC20 operations that throw on failure (when the token
               * contract returns false). Tokens that return no value (and instead revert or
               * throw on failure) are also supported, non-reverting calls are assumed to be
               * successful.
               * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
               * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
               */
              library SafeERC20 {
                  using SafeMath for uint256;
                  using Address for address;
                  function safeTransfer(IERC20 token, address to, uint256 value) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                  }
                  function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                  }
                  /**
                   * @dev Deprecated. This function has issues similar to the ones found in
                   * {IERC20-approve}, and its usage is discouraged.
                   *
                   * Whenever possible, use {safeIncreaseAllowance} and
                   * {safeDecreaseAllowance} instead.
                   */
                  function safeApprove(IERC20 token, address spender, uint256 value) internal {
                      // safeApprove should only be called when setting an initial allowance,
                      // or when resetting it to zero. To increase and decrease it, use
                      // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                      // solhint-disable-next-line max-line-length
                      require((value == 0) || (token.allowance(address(this), spender) == 0),
                          "SafeERC20: approve from non-zero to non-zero allowance"
                      );
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                  }
                  function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                      uint256 newAllowance = token.allowance(address(this), spender).add(value);
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
                      uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                  }
                  /**
                   * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                   * on the return value: the return value is optional (but if data is returned, it must not be false).
                   * @param token The token targeted by the call.
                   * @param data The call data (encoded using abi.encode or one of its variants).
                   */
                  function _callOptionalReturn(IERC20 token, bytes memory data) private {
                      // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                      // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                      // the target address contains contract code and also asserts for success in the low-level call.
                      bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                      if (returndata.length > 0) { // Return data is optional
                          // solhint-disable-next-line max-line-length
                          require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                      }
                  }
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /**
               * @dev Interface of the ERC20 standard as defined in the EIP.
               */
              interface IERC20 {
                  /**
                   * @dev Returns the amount of tokens in existence.
                   */
                  function totalSupply() external view returns (uint256);
                  /**
                   * @dev Returns the amount of tokens owned by `account`.
                   */
                  function balanceOf(address account) external view returns (uint256);
                  /**
                   * @dev Moves `amount` tokens from the caller's account to `recipient`.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transfer(address recipient, uint256 amount) external returns (bool);
                  /**
                   * @dev Returns the remaining number of tokens that `spender` will be
                   * allowed to spend on behalf of `owner` through {transferFrom}. This is
                   * zero by default.
                   *
                   * This value changes when {approve} or {transferFrom} are called.
                   */
                  function allowance(address owner, address spender) external view returns (uint256);
                  /**
                   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * IMPORTANT: Beware that changing an allowance with this method brings the risk
                   * that someone may use both the old and the new allowance by unfortunate
                   * transaction ordering. One possible solution to mitigate this race
                   * condition is to first reduce the spender's allowance to 0 and set the
                   * desired value afterwards:
                   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
                   *
                   * Emits an {Approval} event.
                   */
                  function approve(address spender, uint256 amount) external returns (bool);
                  /**
                   * @dev Moves `amount` tokens from `sender` to `recipient` using the
                   * allowance mechanism. `amount` is then deducted from the caller's
                   * allowance.
                   *
                   * Returns a boolean value indicating whether the operation succeeded.
                   *
                   * Emits a {Transfer} event.
                   */
                  function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
                  /**
                   * @dev Emitted when `value` tokens are moved from one account (`from`) to
                   * another (`to`).
                   *
                   * Note that `value` may be zero.
                   */
                  event Transfer(address indexed from, address indexed to, uint256 value);
                  /**
                   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
                   * a call to {approve}. `value` is the new allowance.
                   */
                  event Approval(address indexed owner, address indexed spender, uint256 value);
              }
              // SPDX-License-Identifier: MIT
              pragma solidity >=0.6.0 <0.8.0;
              /**
               * @dev Wrappers over Solidity's arithmetic operations with added overflow
               * checks.
               *
               * Arithmetic operations in Solidity wrap on overflow. This can easily result
               * in bugs, because programmers usually assume that an overflow raises an
               * error, which is the standard behavior in high level programming languages.
               * `SafeMath` restores this intuition by reverting the transaction when an
               * operation overflows.
               *
               * Using this library instead of the unchecked operations eliminates an entire
               * class of bugs, so it's recommended to use it always.
               */
              library SafeMath {
                  /**
                   * @dev Returns the addition of two unsigned integers, with an overflow flag.
                   *
                   * _Available since v3.4._
                   */
                  function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                      uint256 c = a + b;
                      if (c < a) return (false, 0);
                      return (true, c);
                  }
                  /**
                   * @dev Returns the substraction of two unsigned integers, with an overflow flag.
                   *
                   * _Available since v3.4._
                   */
                  function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                      if (b > a) return (false, 0);
                      return (true, a - b);
                  }
                  /**
                   * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
                   *
                   * _Available since v3.4._
                   */
                  function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                      // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                      // benefit is lost if 'b' is also tested.
                      // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                      if (a == 0) return (true, 0);
                      uint256 c = a * b;
                      if (c / a != b) return (false, 0);
                      return (true, c);
                  }
                  /**
                   * @dev Returns the division of two unsigned integers, with a division by zero flag.
                   *
                   * _Available since v3.4._
                   */
                  function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                      if (b == 0) return (false, 0);
                      return (true, a / b);
                  }
                  /**
                   * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
                   *
                   * _Available since v3.4._
                   */
                  function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                      if (b == 0) return (false, 0);
                      return (true, a % b);
                  }
                  /**
                   * @dev Returns the addition of two unsigned integers, reverting on
                   * overflow.
                   *
                   * Counterpart to Solidity's `+` operator.
                   *
                   * Requirements:
                   *
                   * - Addition cannot overflow.
                   */
                  function add(uint256 a, uint256 b) internal pure returns (uint256) {
                      uint256 c = a + b;
                      require(c >= a, "SafeMath: addition overflow");
                      return c;
                  }
                  /**
                   * @dev Returns the subtraction of two unsigned integers, reverting on
                   * overflow (when the result is negative).
                   *
                   * Counterpart to Solidity's `-` operator.
                   *
                   * Requirements:
                   *
                   * - Subtraction cannot overflow.
                   */
                  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                      require(b <= a, "SafeMath: subtraction overflow");
                      return a - b;
                  }
                  /**
                   * @dev Returns the multiplication of two unsigned integers, reverting on
                   * overflow.
                   *
                   * Counterpart to Solidity's `*` operator.
                   *
                   * Requirements:
                   *
                   * - Multiplication cannot overflow.
                   */
                  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                      if (a == 0) return 0;
                      uint256 c = a * b;
                      require(c / a == b, "SafeMath: multiplication overflow");
                      return c;
                  }
                  /**
                   * @dev Returns the integer division of two unsigned integers, reverting on
                   * division by zero. The result is rounded towards zero.
                   *
                   * Counterpart to Solidity's `/` operator. Note: this function uses a
                   * `revert` opcode (which leaves remaining gas untouched) while Solidity
                   * uses an invalid opcode to revert (consuming all remaining gas).
                   *
                   * Requirements:
                   *
                   * - The divisor cannot be zero.
                   */
                  function div(uint256 a, uint256 b) internal pure returns (uint256) {
                      require(b > 0, "SafeMath: division by zero");
                      return a / b;
                  }
                  /**
                   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                   * reverting when dividing by zero.
                   *
                   * Counterpart to Solidity's `%` operator. This function uses a `revert`
                   * opcode (which leaves remaining gas untouched) while Solidity uses an
                   * invalid opcode to revert (consuming all remaining gas).
                   *
                   * Requirements:
                   *
                   * - The divisor cannot be zero.
                   */
                  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                      require(b > 0, "SafeMath: modulo by zero");
                      return a % b;
                  }
                  /**
                   * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                   * overflow (when the result is negative).
                   *
                   * CAUTION: This function is deprecated because it requires allocating memory for the error
                   * message unnecessarily. For custom revert reasons use {trySub}.
                   *
                   * Counterpart to Solidity's `-` operator.
                   *
                   * Requirements:
                   *
                   * - Subtraction cannot overflow.
                   */
                  function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                      require(b <= a, errorMessage);
                      return a - b;
                  }
                  /**
                   * @dev Returns the integer division of two unsigned integers, reverting with custom message on
                   * division by zero. The result is rounded towards zero.
                   *
                   * CAUTION: This function is deprecated because it requires allocating memory for the error
                   * message unnecessarily. For custom revert reasons use {tryDiv}.
                   *
                   * Counterpart to Solidity's `/` operator. Note: this function uses a
                   * `revert` opcode (which leaves remaining gas untouched) while Solidity
                   * uses an invalid opcode to revert (consuming all remaining gas).
                   *
                   * Requirements:
                   *
                   * - The divisor cannot be zero.
                   */
                  function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                      require(b > 0, errorMessage);
                      return a / b;
                  }
                  /**
                   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                   * reverting with custom message when dividing by zero.
                   *
                   * CAUTION: This function is deprecated because it requires allocating memory for the error
                   * message unnecessarily. For custom revert reasons use {tryMod}.
                   *
                   * Counterpart to Solidity's `%` operator. This function uses a `revert`
                   * opcode (which leaves remaining gas untouched) while Solidity uses an
                   * invalid opcode to revert (consuming all remaining gas).
                   *
                   * Requirements:
                   *
                   * - The divisor cannot be zero.
                   */
                  function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                      require(b > 0, errorMessage);
                      return a % b;
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { FiatTokenV2 } from "./FiatTokenV2.sol";
              // solhint-disable func-name-mixedcase
              /**
               * @title FiatToken V2.1
               * @notice ERC20 Token backed by fiat reserves, version 2.1
               */
              contract FiatTokenV2_1 is FiatTokenV2 {
                  /**
                   * @notice Initialize v2.1
                   * @param lostAndFound  The address to which the locked funds are sent
                   */
                  function initializeV2_1(address lostAndFound) external {
                      // solhint-disable-next-line reason-string
                      require(_initializedVersion == 1);
                      uint256 lockedAmount = _balanceOf(address(this));
                      if (lockedAmount > 0) {
                          _transfer(address(this), lostAndFound, lockedAmount);
                      }
                      _blacklist(address(this));
                      _initializedVersion = 2;
                  }
                  /**
                   * @notice Version string for the EIP712 domain separator
                   * @return Version string
                   */
                  function version() external pure returns (string memory) {
                      return "2";
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { FiatTokenV1_1 } from "../v1.1/FiatTokenV1_1.sol";
              import { EIP712 } from "../util/EIP712.sol";
              import { EIP3009 } from "./EIP3009.sol";
              import { EIP2612 } from "./EIP2612.sol";
              /**
               * @title FiatToken V2
               * @notice ERC20 Token backed by fiat reserves, version 2
               */
              contract FiatTokenV2 is FiatTokenV1_1, EIP3009, EIP2612 {
                  uint8 internal _initializedVersion;
                  /**
                   * @notice Initialize v2
                   * @param newName   New token name
                   */
                  function initializeV2(string calldata newName) external {
                      // solhint-disable-next-line reason-string
                      require(initialized && _initializedVersion == 0);
                      name = newName;
                      _DEPRECATED_CACHED_DOMAIN_SEPARATOR = EIP712.makeDomainSeparator(
                          newName,
                          "2"
                      );
                      _initializedVersion = 1;
                  }
                  /**
                   * @notice Increase the allowance by a given increment
                   * @param spender   Spender's address
                   * @param increment Amount of increase in allowance
                   * @return True if successful
                   */
                  function increaseAllowance(address spender, uint256 increment)
                      external
                      virtual
                      whenNotPaused
                      notBlacklisted(msg.sender)
                      notBlacklisted(spender)
                      returns (bool)
                  {
                      _increaseAllowance(msg.sender, spender, increment);
                      return true;
                  }
                  /**
                   * @notice Decrease the allowance by a given decrement
                   * @param spender   Spender's address
                   * @param decrement Amount of decrease in allowance
                   * @return True if successful
                   */
                  function decreaseAllowance(address spender, uint256 decrement)
                      external
                      virtual
                      whenNotPaused
                      notBlacklisted(msg.sender)
                      notBlacklisted(spender)
                      returns (bool)
                  {
                      _decreaseAllowance(msg.sender, spender, decrement);
                      return true;
                  }
                  /**
                   * @notice Execute a transfer with a signed authorization
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param v             v of the signature
                   * @param r             r of the signature
                   * @param s             s of the signature
                   */
                  function transferWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                      _transferWithAuthorization(
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce,
                          v,
                          r,
                          s
                      );
                  }
                  /**
                   * @notice Receive a transfer with a signed authorization from the payer
                   * @dev This has an additional check to ensure that the payee's address
                   * matches the caller of this function to prevent front-running attacks.
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param v             v of the signature
                   * @param r             r of the signature
                   * @param s             s of the signature
                   */
                  function receiveWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external whenNotPaused notBlacklisted(from) notBlacklisted(to) {
                      _receiveWithAuthorization(
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce,
                          v,
                          r,
                          s
                      );
                  }
                  /**
                   * @notice Attempt to cancel an authorization
                   * @dev Works only if the authorization is not yet used.
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   * @param v             v of the signature
                   * @param r             r of the signature
                   * @param s             s of the signature
                   */
                  function cancelAuthorization(
                      address authorizer,
                      bytes32 nonce,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) external whenNotPaused {
                      _cancelAuthorization(authorizer, nonce, v, r, s);
                  }
                  /**
                   * @notice Update allowance with a signed permit
                   * @param owner       Token owner's address (Authorizer)
                   * @param spender     Spender's address
                   * @param value       Amount of allowance
                   * @param deadline    The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                   * @param v           v of the signature
                   * @param r           r of the signature
                   * @param s           s of the signature
                   */
                  function permit(
                      address owner,
                      address spender,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  )
                      external
                      virtual
                      whenNotPaused
                      notBlacklisted(owner)
                      notBlacklisted(spender)
                  {
                      _permit(owner, spender, value, deadline, v, r, s);
                  }
                  /**
                   * @dev Internal function to increase the allowance by a given increment
                   * @param owner     Token owner's address
                   * @param spender   Spender's address
                   * @param increment Amount of increase
                   */
                  function _increaseAllowance(
                      address owner,
                      address spender,
                      uint256 increment
                  ) internal override {
                      _approve(owner, spender, allowed[owner][spender].add(increment));
                  }
                  /**
                   * @dev Internal function to decrease the allowance by a given decrement
                   * @param owner     Token owner's address
                   * @param spender   Spender's address
                   * @param decrement Amount of decrease
                   */
                  function _decreaseAllowance(
                      address owner,
                      address spender,
                      uint256 decrement
                  ) internal override {
                      _approve(
                          owner,
                          spender,
                          allowed[owner][spender].sub(
                              decrement,
                              "ERC20: decreased allowance below zero"
                          )
                      );
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              // solhint-disable func-name-mixedcase
              /**
               * @title EIP712 Domain
               */
              contract EIP712Domain {
                  // was originally DOMAIN_SEPARATOR
                  // but that has been moved to a method so we can override it in V2_2+
                  bytes32 internal _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
                  /**
                   * @notice Get the EIP712 Domain Separator.
                   * @return The bytes32 EIP712 domain separator.
                   */
                  function DOMAIN_SEPARATOR() external view returns (bytes32) {
                      return _domainSeparator();
                  }
                  /**
                   * @dev Internal method to get the EIP712 Domain Separator.
                   * @return The bytes32 EIP712 domain separator.
                   */
                  function _domainSeparator() internal virtual view returns (bytes32) {
                      return _DEPRECATED_CACHED_DOMAIN_SEPARATOR;
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
              import { EIP712Domain } from "./EIP712Domain.sol";
              import { SignatureChecker } from "../util/SignatureChecker.sol";
              import { MessageHashUtils } from "../util/MessageHashUtils.sol";
              /**
               * @title EIP-3009
               * @notice Provide internal implementation for gas-abstracted transfers
               * @dev Contracts that inherit from this must wrap these with publicly
               * accessible functions, optionally adding modifiers where necessary
               */
              abstract contract EIP3009 is AbstractFiatTokenV2, EIP712Domain {
                  // keccak256("TransferWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                  bytes32
                      public constant TRANSFER_WITH_AUTHORIZATION_TYPEHASH = 0x7c7c6cdb67a18743f49ec6fa9b35f50d52ed05cbed4cc592e13b44501c1a2267;
                  // keccak256("ReceiveWithAuthorization(address from,address to,uint256 value,uint256 validAfter,uint256 validBefore,bytes32 nonce)")
                  bytes32
                      public constant RECEIVE_WITH_AUTHORIZATION_TYPEHASH = 0xd099cc98ef71107a616c4f0f941f04c322d8e254fe26b3c6668db87aae413de8;
                  // keccak256("CancelAuthorization(address authorizer,bytes32 nonce)")
                  bytes32
                      public constant CANCEL_AUTHORIZATION_TYPEHASH = 0x158b0a9edf7a828aad02f63cd515c68ef2f50ba807396f6d12842833a1597429;
                  /**
                   * @dev authorizer address => nonce => bool (true if nonce is used)
                   */
                  mapping(address => mapping(bytes32 => bool)) private _authorizationStates;
                  event AuthorizationUsed(address indexed authorizer, bytes32 indexed nonce);
                  event AuthorizationCanceled(
                      address indexed authorizer,
                      bytes32 indexed nonce
                  );
                  /**
                   * @notice Returns the state of an authorization
                   * @dev Nonces are randomly generated 32-byte data unique to the
                   * authorizer's address
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   * @return True if the nonce is used
                   */
                  function authorizationState(address authorizer, bytes32 nonce)
                      external
                      view
                      returns (bool)
                  {
                      return _authorizationStates[authorizer][nonce];
                  }
                  /**
                   * @notice Execute a transfer with a signed authorization
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param v             v of the signature
                   * @param r             r of the signature
                   * @param s             s of the signature
                   */
                  function _transferWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal {
                      _transferWithAuthorization(
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce,
                          abi.encodePacked(r, s, v)
                      );
                  }
                  /**
                   * @notice Execute a transfer with a signed authorization
                   * @dev EOA wallet signatures should be packed in the order of r, s, v.
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                   */
                  function _transferWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      bytes memory signature
                  ) internal {
                      _requireValidAuthorization(from, nonce, validAfter, validBefore);
                      _requireValidSignature(
                          from,
                          keccak256(
                              abi.encode(
                                  TRANSFER_WITH_AUTHORIZATION_TYPEHASH,
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce
                              )
                          ),
                          signature
                      );
                      _markAuthorizationAsUsed(from, nonce);
                      _transfer(from, to, value);
                  }
                  /**
                   * @notice Receive a transfer with a signed authorization from the payer
                   * @dev This has an additional check to ensure that the payee's address
                   * matches the caller of this function to prevent front-running attacks.
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param v             v of the signature
                   * @param r             r of the signature
                   * @param s             s of the signature
                   */
                  function _receiveWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal {
                      _receiveWithAuthorization(
                          from,
                          to,
                          value,
                          validAfter,
                          validBefore,
                          nonce,
                          abi.encodePacked(r, s, v)
                      );
                  }
                  /**
                   * @notice Receive a transfer with a signed authorization from the payer
                   * @dev This has an additional check to ensure that the payee's address
                   * matches the caller of this function to prevent front-running attacks.
                   * EOA wallet signatures should be packed in the order of r, s, v.
                   * @param from          Payer's address (Authorizer)
                   * @param to            Payee's address
                   * @param value         Amount to be transferred
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   * @param nonce         Unique nonce
                   * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                   */
                  function _receiveWithAuthorization(
                      address from,
                      address to,
                      uint256 value,
                      uint256 validAfter,
                      uint256 validBefore,
                      bytes32 nonce,
                      bytes memory signature
                  ) internal {
                      require(to == msg.sender, "FiatTokenV2: caller must be the payee");
                      _requireValidAuthorization(from, nonce, validAfter, validBefore);
                      _requireValidSignature(
                          from,
                          keccak256(
                              abi.encode(
                                  RECEIVE_WITH_AUTHORIZATION_TYPEHASH,
                                  from,
                                  to,
                                  value,
                                  validAfter,
                                  validBefore,
                                  nonce
                              )
                          ),
                          signature
                      );
                      _markAuthorizationAsUsed(from, nonce);
                      _transfer(from, to, value);
                  }
                  /**
                   * @notice Attempt to cancel an authorization
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   * @param v             v of the signature
                   * @param r             r of the signature
                   * @param s             s of the signature
                   */
                  function _cancelAuthorization(
                      address authorizer,
                      bytes32 nonce,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal {
                      _cancelAuthorization(authorizer, nonce, abi.encodePacked(r, s, v));
                  }
                  /**
                   * @notice Attempt to cancel an authorization
                   * @dev EOA wallet signatures should be packed in the order of r, s, v.
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                   */
                  function _cancelAuthorization(
                      address authorizer,
                      bytes32 nonce,
                      bytes memory signature
                  ) internal {
                      _requireUnusedAuthorization(authorizer, nonce);
                      _requireValidSignature(
                          authorizer,
                          keccak256(
                              abi.encode(CANCEL_AUTHORIZATION_TYPEHASH, authorizer, nonce)
                          ),
                          signature
                      );
                      _authorizationStates[authorizer][nonce] = true;
                      emit AuthorizationCanceled(authorizer, nonce);
                  }
                  /**
                   * @notice Validates that signature against input data struct
                   * @param signer        Signer's address
                   * @param dataHash      Hash of encoded data struct
                   * @param signature     Signature byte array produced by an EOA wallet or a contract wallet
                   */
                  function _requireValidSignature(
                      address signer,
                      bytes32 dataHash,
                      bytes memory signature
                  ) private view {
                      require(
                          SignatureChecker.isValidSignatureNow(
                              signer,
                              MessageHashUtils.toTypedDataHash(_domainSeparator(), dataHash),
                              signature
                          ),
                          "FiatTokenV2: invalid signature"
                      );
                  }
                  /**
                   * @notice Check that an authorization is unused
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   */
                  function _requireUnusedAuthorization(address authorizer, bytes32 nonce)
                      private
                      view
                  {
                      require(
                          !_authorizationStates[authorizer][nonce],
                          "FiatTokenV2: authorization is used or canceled"
                      );
                  }
                  /**
                   * @notice Check that authorization is valid
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   * @param validAfter    The time after which this is valid (unix time)
                   * @param validBefore   The time before which this is valid (unix time)
                   */
                  function _requireValidAuthorization(
                      address authorizer,
                      bytes32 nonce,
                      uint256 validAfter,
                      uint256 validBefore
                  ) private view {
                      require(
                          now > validAfter,
                          "FiatTokenV2: authorization is not yet valid"
                      );
                      require(now < validBefore, "FiatTokenV2: authorization is expired");
                      _requireUnusedAuthorization(authorizer, nonce);
                  }
                  /**
                   * @notice Mark an authorization as used
                   * @param authorizer    Authorizer's address
                   * @param nonce         Nonce of the authorization
                   */
                  function _markAuthorizationAsUsed(address authorizer, bytes32 nonce)
                      private
                  {
                      _authorizationStates[authorizer][nonce] = true;
                      emit AuthorizationUsed(authorizer, nonce);
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { AbstractFiatTokenV2 } from "./AbstractFiatTokenV2.sol";
              import { EIP712Domain } from "./EIP712Domain.sol";
              import { MessageHashUtils } from "../util/MessageHashUtils.sol";
              import { SignatureChecker } from "../util/SignatureChecker.sol";
              /**
               * @title EIP-2612
               * @notice Provide internal implementation for gas-abstracted approvals
               */
              abstract contract EIP2612 is AbstractFiatTokenV2, EIP712Domain {
                  // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
                  bytes32
                      public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
                  mapping(address => uint256) private _permitNonces;
                  /**
                   * @notice Nonces for permit
                   * @param owner Token owner's address (Authorizer)
                   * @return Next nonce
                   */
                  function nonces(address owner) external view returns (uint256) {
                      return _permitNonces[owner];
                  }
                  /**
                   * @notice Verify a signed approval permit and execute if valid
                   * @param owner     Token owner's address (Authorizer)
                   * @param spender   Spender's address
                   * @param value     Amount of allowance
                   * @param deadline  The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                   * @param v         v of the signature
                   * @param r         r of the signature
                   * @param s         s of the signature
                   */
                  function _permit(
                      address owner,
                      address spender,
                      uint256 value,
                      uint256 deadline,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal {
                      _permit(owner, spender, value, deadline, abi.encodePacked(r, s, v));
                  }
                  /**
                   * @notice Verify a signed approval permit and execute if valid
                   * @dev EOA wallet signatures should be packed in the order of r, s, v.
                   * @param owner      Token owner's address (Authorizer)
                   * @param spender    Spender's address
                   * @param value      Amount of allowance
                   * @param deadline   The time at which the signature expires (unix time), or max uint256 value to signal no expiration
                   * @param signature  Signature byte array signed by an EOA wallet or a contract wallet
                   */
                  function _permit(
                      address owner,
                      address spender,
                      uint256 value,
                      uint256 deadline,
                      bytes memory signature
                  ) internal {
                      require(
                          deadline == type(uint256).max || deadline >= now,
                          "FiatTokenV2: permit is expired"
                      );
                      bytes32 typedDataHash = MessageHashUtils.toTypedDataHash(
                          _domainSeparator(),
                          keccak256(
                              abi.encode(
                                  PERMIT_TYPEHASH,
                                  owner,
                                  spender,
                                  value,
                                  _permitNonces[owner]++,
                                  deadline
                              )
                          )
                      );
                      require(
                          SignatureChecker.isValidSignatureNow(
                              owner,
                              typedDataHash,
                              signature
                          ),
                          "EIP2612: invalid signature"
                      );
                      _approve(owner, spender, value);
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { AbstractFiatTokenV1 } from "../v1/AbstractFiatTokenV1.sol";
              abstract contract AbstractFiatTokenV2 is AbstractFiatTokenV1 {
                  function _increaseAllowance(
                      address owner,
                      address spender,
                      uint256 increment
                  ) internal virtual;
                  function _decreaseAllowance(
                      address owner,
                      address spender,
                      uint256 decrement
                  ) internal virtual;
              }
              /**
               * SPDX-License-Identifier: MIT
               *
               * Copyright (c) 2016 Smart Contract Solutions, Inc.
               * Copyright (c) 2018-2020 CENTRE SECZ
               *
               * Permission is hereby granted, free of charge, to any person obtaining a copy
               * of this software and associated documentation files (the "Software"), to deal
               * in the Software without restriction, including without limitation the rights
               * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
               * copies of the Software, and to permit persons to whom the Software is
               * furnished to do so, subject to the following conditions:
               *
               * The above copyright notice and this permission notice shall be included in
               * copies or substantial portions of the Software.
               *
               * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
               * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
               * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
               * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
               * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
               * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
               * SOFTWARE.
               */
              pragma solidity 0.6.12;
              import { Ownable } from "./Ownable.sol";
              /**
               * @notice Base contract which allows children to implement an emergency stop
               * mechanism
               * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/feb665136c0dae9912e08397c1a21c4af3651ef3/contracts/lifecycle/Pausable.sol
               * Modifications:
               * 1. Added pauser role, switched pause/unpause to be onlyPauser (6/14/2018)
               * 2. Removed whenNotPause/whenPaused from pause/unpause (6/14/2018)
               * 3. Removed whenPaused (6/14/2018)
               * 4. Switches ownable library to use ZeppelinOS (7/12/18)
               * 5. Remove constructor (7/13/18)
               * 6. Reformat, conform to Solidity 0.6 syntax and add error messages (5/13/20)
               * 7. Make public functions external (5/27/20)
               */
              contract Pausable is Ownable {
                  event Pause();
                  event Unpause();
                  event PauserChanged(address indexed newAddress);
                  address public pauser;
                  bool public paused = false;
                  /**
                   * @dev Modifier to make a function callable only when the contract is not paused.
                   */
                  modifier whenNotPaused() {
                      require(!paused, "Pausable: paused");
                      _;
                  }
                  /**
                   * @dev throws if called by any account other than the pauser
                   */
                  modifier onlyPauser() {
                      require(msg.sender == pauser, "Pausable: caller is not the pauser");
                      _;
                  }
                  /**
                   * @dev called by the owner to pause, triggers stopped state
                   */
                  function pause() external onlyPauser {
                      paused = true;
                      emit Pause();
                  }
                  /**
                   * @dev called by the owner to unpause, returns to normal state
                   */
                  function unpause() external onlyPauser {
                      paused = false;
                      emit Unpause();
                  }
                  /**
                   * @notice Updates the pauser address.
                   * @param _newPauser The address of the new pauser.
                   */
                  function updatePauser(address _newPauser) external onlyOwner {
                      require(
                          _newPauser != address(0),
                          "Pausable: new pauser is the zero address"
                      );
                      pauser = _newPauser;
                      emit PauserChanged(pauser);
                  }
              }
              /**
               * SPDX-License-Identifier: MIT
               *
               * Copyright (c) 2018 zOS Global Limited.
               * Copyright (c) 2018-2020 CENTRE SECZ
               *
               * Permission is hereby granted, free of charge, to any person obtaining a copy
               * of this software and associated documentation files (the "Software"), to deal
               * in the Software without restriction, including without limitation the rights
               * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
               * copies of the Software, and to permit persons to whom the Software is
               * furnished to do so, subject to the following conditions:
               *
               * The above copyright notice and this permission notice shall be included in
               * copies or substantial portions of the Software.
               *
               * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
               * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
               * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
               * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
               * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
               * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
               * SOFTWARE.
               */
              pragma solidity 0.6.12;
              /**
               * @notice The Ownable contract has an owner address, and provides basic
               * authorization control functions
               * @dev Forked from https://github.com/OpenZeppelin/openzeppelin-labs/blob/3887ab77b8adafba4a26ace002f3a684c1a3388b/upgradeability_ownership/contracts/ownership/Ownable.sol
               * Modifications:
               * 1. Consolidate OwnableStorage into this contract (7/13/18)
               * 2. Reformat, conform to Solidity 0.6 syntax, and add error messages (5/13/20)
               * 3. Make public functions external (5/27/20)
               */
              contract Ownable {
                  // Owner of the contract
                  address private _owner;
                  /**
                   * @dev Event to show ownership has been transferred
                   * @param previousOwner representing the address of the previous owner
                   * @param newOwner representing the address of the new owner
                   */
                  event OwnershipTransferred(address previousOwner, address newOwner);
                  /**
                   * @dev The constructor sets the original owner of the contract to the sender account.
                   */
                  constructor() public {
                      setOwner(msg.sender);
                  }
                  /**
                   * @dev Tells the address of the owner
                   * @return the address of the owner
                   */
                  function owner() external view returns (address) {
                      return _owner;
                  }
                  /**
                   * @dev Sets a new owner address
                   */
                  function setOwner(address newOwner) internal {
                      _owner = newOwner;
                  }
                  /**
                   * @dev Throws if called by any account other than the owner.
                   */
                  modifier onlyOwner() {
                      require(msg.sender == _owner, "Ownable: caller is not the owner");
                      _;
                  }
                  /**
                   * @dev Allows the current owner to transfer control of the contract to a newOwner.
                   * @param newOwner The address to transfer ownership to.
                   */
                  function transferOwnership(address newOwner) external onlyOwner {
                      require(
                          newOwner != address(0),
                          "Ownable: new owner is the zero address"
                      );
                      emit OwnershipTransferred(_owner, newOwner);
                      setOwner(newOwner);
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { SafeMath } from "@openzeppelin/contracts/math/SafeMath.sol";
              import { AbstractFiatTokenV1 } from "./AbstractFiatTokenV1.sol";
              import { Ownable } from "./Ownable.sol";
              import { Pausable } from "./Pausable.sol";
              import { Blacklistable } from "./Blacklistable.sol";
              /**
               * @title FiatToken
               * @dev ERC20 Token backed by fiat reserves
               */
              contract FiatTokenV1 is AbstractFiatTokenV1, Ownable, Pausable, Blacklistable {
                  using SafeMath for uint256;
                  string public name;
                  string public symbol;
                  uint8 public decimals;
                  string public currency;
                  address public masterMinter;
                  bool internal initialized;
                  /// @dev A mapping that stores the balance and blacklist states for a given address.
                  /// The first bit defines whether the address is blacklisted (1 if blacklisted, 0 otherwise).
                  /// The last 255 bits define the balance for the address.
                  mapping(address => uint256) internal balanceAndBlacklistStates;
                  mapping(address => mapping(address => uint256)) internal allowed;
                  uint256 internal totalSupply_ = 0;
                  mapping(address => bool) internal minters;
                  mapping(address => uint256) internal minterAllowed;
                  event Mint(address indexed minter, address indexed to, uint256 amount);
                  event Burn(address indexed burner, uint256 amount);
                  event MinterConfigured(address indexed minter, uint256 minterAllowedAmount);
                  event MinterRemoved(address indexed oldMinter);
                  event MasterMinterChanged(address indexed newMasterMinter);
                  /**
                   * @notice Initializes the fiat token contract.
                   * @param tokenName       The name of the fiat token.
                   * @param tokenSymbol     The symbol of the fiat token.
                   * @param tokenCurrency   The fiat currency that the token represents.
                   * @param tokenDecimals   The number of decimals that the token uses.
                   * @param newMasterMinter The masterMinter address for the fiat token.
                   * @param newPauser       The pauser address for the fiat token.
                   * @param newBlacklister  The blacklister address for the fiat token.
                   * @param newOwner        The owner of the fiat token.
                   */
                  function initialize(
                      string memory tokenName,
                      string memory tokenSymbol,
                      string memory tokenCurrency,
                      uint8 tokenDecimals,
                      address newMasterMinter,
                      address newPauser,
                      address newBlacklister,
                      address newOwner
                  ) public {
                      require(!initialized, "FiatToken: contract is already initialized");
                      require(
                          newMasterMinter != address(0),
                          "FiatToken: new masterMinter is the zero address"
                      );
                      require(
                          newPauser != address(0),
                          "FiatToken: new pauser is the zero address"
                      );
                      require(
                          newBlacklister != address(0),
                          "FiatToken: new blacklister is the zero address"
                      );
                      require(
                          newOwner != address(0),
                          "FiatToken: new owner is the zero address"
                      );
                      name = tokenName;
                      symbol = tokenSymbol;
                      currency = tokenCurrency;
                      decimals = tokenDecimals;
                      masterMinter = newMasterMinter;
                      pauser = newPauser;
                      blacklister = newBlacklister;
                      setOwner(newOwner);
                      initialized = true;
                  }
                  /**
                   * @dev Throws if called by any account other than a minter.
                   */
                  modifier onlyMinters() {
                      require(minters[msg.sender], "FiatToken: caller is not a minter");
                      _;
                  }
                  /**
                   * @notice Mints fiat tokens to an address.
                   * @param _to The address that will receive the minted tokens.
                   * @param _amount The amount of tokens to mint. Must be less than or equal
                   * to the minterAllowance of the caller.
                   * @return True if the operation was successful.
                   */
                  function mint(address _to, uint256 _amount)
                      external
                      whenNotPaused
                      onlyMinters
                      notBlacklisted(msg.sender)
                      notBlacklisted(_to)
                      returns (bool)
                  {
                      require(_to != address(0), "FiatToken: mint to the zero address");
                      require(_amount > 0, "FiatToken: mint amount not greater than 0");
                      uint256 mintingAllowedAmount = minterAllowed[msg.sender];
                      require(
                          _amount <= mintingAllowedAmount,
                          "FiatToken: mint amount exceeds minterAllowance"
                      );
                      totalSupply_ = totalSupply_.add(_amount);
                      _setBalance(_to, _balanceOf(_to).add(_amount));
                      minterAllowed[msg.sender] = mintingAllowedAmount.sub(_amount);
                      emit Mint(msg.sender, _to, _amount);
                      emit Transfer(address(0), _to, _amount);
                      return true;
                  }
                  /**
                   * @dev Throws if called by any account other than the masterMinter
                   */
                  modifier onlyMasterMinter() {
                      require(
                          msg.sender == masterMinter,
                          "FiatToken: caller is not the masterMinter"
                      );
                      _;
                  }
                  /**
                   * @notice Gets the minter allowance for an account.
                   * @param minter The address to check.
                   * @return The remaining minter allowance for the account.
                   */
                  function minterAllowance(address minter) external view returns (uint256) {
                      return minterAllowed[minter];
                  }
                  /**
                   * @notice Checks if an account is a minter.
                   * @param account The address to check.
                   * @return True if the account is a minter, false if the account is not a minter.
                   */
                  function isMinter(address account) external view returns (bool) {
                      return minters[account];
                  }
                  /**
                   * @notice Gets the remaining amount of fiat tokens a spender is allowed to transfer on
                   * behalf of the token owner.
                   * @param owner   The token owner's address.
                   * @param spender The spender's address.
                   * @return The remaining allowance.
                   */
                  function allowance(address owner, address spender)
                      external
                      override
                      view
                      returns (uint256)
                  {
                      return allowed[owner][spender];
                  }
                  /**
                   * @notice Gets the totalSupply of the fiat token.
                   * @return The totalSupply of the fiat token.
                   */
                  function totalSupply() external override view returns (uint256) {
                      return totalSupply_;
                  }
                  /**
                   * @notice Gets the fiat token balance of an account.
                   * @param account  The address to check.
                   * @return balance The fiat token balance of the account.
                   */
                  function balanceOf(address account)
                      external
                      override
                      view
                      returns (uint256)
                  {
                      return _balanceOf(account);
                  }
                  /**
                   * @notice Sets a fiat token allowance for a spender to spend on behalf of the caller.
                   * @param spender The spender's address.
                   * @param value   The allowance amount.
                   * @return True if the operation was successful.
                   */
                  function approve(address spender, uint256 value)
                      external
                      virtual
                      override
                      whenNotPaused
                      notBlacklisted(msg.sender)
                      notBlacklisted(spender)
                      returns (bool)
                  {
                      _approve(msg.sender, spender, value);
                      return true;
                  }
                  /**
                   * @dev Internal function to set allowance.
                   * @param owner     Token owner's address.
                   * @param spender   Spender's address.
                   * @param value     Allowance amount.
                   */
                  function _approve(
                      address owner,
                      address spender,
                      uint256 value
                  ) internal override {
                      require(owner != address(0), "ERC20: approve from the zero address");
                      require(spender != address(0), "ERC20: approve to the zero address");
                      allowed[owner][spender] = value;
                      emit Approval(owner, spender, value);
                  }
                  /**
                   * @notice Transfers tokens from an address to another by spending the caller's allowance.
                   * @dev The caller must have some fiat token allowance on the payer's tokens.
                   * @param from  Payer's address.
                   * @param to    Payee's address.
                   * @param value Transfer amount.
                   * @return True if the operation was successful.
                   */
                  function transferFrom(
                      address from,
                      address to,
                      uint256 value
                  )
                      external
                      override
                      whenNotPaused
                      notBlacklisted(msg.sender)
                      notBlacklisted(from)
                      notBlacklisted(to)
                      returns (bool)
                  {
                      require(
                          value <= allowed[from][msg.sender],
                          "ERC20: transfer amount exceeds allowance"
                      );
                      _transfer(from, to, value);
                      allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
                      return true;
                  }
                  /**
                   * @notice Transfers tokens from the caller.
                   * @param to    Payee's address.
                   * @param value Transfer amount.
                   * @return True if the operation was successful.
                   */
                  function transfer(address to, uint256 value)
                      external
                      override
                      whenNotPaused
                      notBlacklisted(msg.sender)
                      notBlacklisted(to)
                      returns (bool)
                  {
                      _transfer(msg.sender, to, value);
                      return true;
                  }
                  /**
                   * @dev Internal function to process transfers.
                   * @param from  Payer's address.
                   * @param to    Payee's address.
                   * @param value Transfer amount.
                   */
                  function _transfer(
                      address from,
                      address to,
                      uint256 value
                  ) internal override {
                      require(from != address(0), "ERC20: transfer from the zero address");
                      require(to != address(0), "ERC20: transfer to the zero address");
                      require(
                          value <= _balanceOf(from),
                          "ERC20: transfer amount exceeds balance"
                      );
                      _setBalance(from, _balanceOf(from).sub(value));
                      _setBalance(to, _balanceOf(to).add(value));
                      emit Transfer(from, to, value);
                  }
                  /**
                   * @notice Adds or updates a new minter with a mint allowance.
                   * @param minter The address of the minter.
                   * @param minterAllowedAmount The minting amount allowed for the minter.
                   * @return True if the operation was successful.
                   */
                  function configureMinter(address minter, uint256 minterAllowedAmount)
                      external
                      whenNotPaused
                      onlyMasterMinter
                      returns (bool)
                  {
                      minters[minter] = true;
                      minterAllowed[minter] = minterAllowedAmount;
                      emit MinterConfigured(minter, minterAllowedAmount);
                      return true;
                  }
                  /**
                   * @notice Removes a minter.
                   * @param minter The address of the minter to remove.
                   * @return True if the operation was successful.
                   */
                  function removeMinter(address minter)
                      external
                      onlyMasterMinter
                      returns (bool)
                  {
                      minters[minter] = false;
                      minterAllowed[minter] = 0;
                      emit MinterRemoved(minter);
                      return true;
                  }
                  /**
                   * @notice Allows a minter to burn some of its own tokens.
                   * @dev The caller must be a minter, must not be blacklisted, and the amount to burn
                   * should be less than or equal to the account's balance.
                   * @param _amount the amount of tokens to be burned.
                   */
                  function burn(uint256 _amount)
                      external
                      whenNotPaused
                      onlyMinters
                      notBlacklisted(msg.sender)
                  {
                      uint256 balance = _balanceOf(msg.sender);
                      require(_amount > 0, "FiatToken: burn amount not greater than 0");
                      require(balance >= _amount, "FiatToken: burn amount exceeds balance");
                      totalSupply_ = totalSupply_.sub(_amount);
                      _setBalance(msg.sender, balance.sub(_amount));
                      emit Burn(msg.sender, _amount);
                      emit Transfer(msg.sender, address(0), _amount);
                  }
                  /**
                   * @notice Updates the master minter address.
                   * @param _newMasterMinter The address of the new master minter.
                   */
                  function updateMasterMinter(address _newMasterMinter) external onlyOwner {
                      require(
                          _newMasterMinter != address(0),
                          "FiatToken: new masterMinter is the zero address"
                      );
                      masterMinter = _newMasterMinter;
                      emit MasterMinterChanged(masterMinter);
                  }
                  /**
                   * @inheritdoc Blacklistable
                   */
                  function _blacklist(address _account) internal override {
                      _setBlacklistState(_account, true);
                  }
                  /**
                   * @inheritdoc Blacklistable
                   */
                  function _unBlacklist(address _account) internal override {
                      _setBlacklistState(_account, false);
                  }
                  /**
                   * @dev Helper method that sets the blacklist state of an account.
                   * @param _account         The address of the account.
                   * @param _shouldBlacklist True if the account should be blacklisted, false if the account should be unblacklisted.
                   */
                  function _setBlacklistState(address _account, bool _shouldBlacklist)
                      internal
                      virtual
                  {
                      _deprecatedBlacklisted[_account] = _shouldBlacklist;
                  }
                  /**
                   * @dev Helper method that sets the balance of an account.
                   * @param _account The address of the account.
                   * @param _balance The new fiat token balance of the account.
                   */
                  function _setBalance(address _account, uint256 _balance) internal virtual {
                      balanceAndBlacklistStates[_account] = _balance;
                  }
                  /**
                   * @inheritdoc Blacklistable
                   */
                  function _isBlacklisted(address _account)
                      internal
                      virtual
                      override
                      view
                      returns (bool)
                  {
                      return _deprecatedBlacklisted[_account];
                  }
                  /**
                   * @dev Helper method to obtain the balance of an account.
                   * @param _account  The address of the account.
                   * @return          The fiat token balance of the account.
                   */
                  function _balanceOf(address _account)
                      internal
                      virtual
                      view
                      returns (uint256)
                  {
                      return balanceAndBlacklistStates[_account];
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { Ownable } from "./Ownable.sol";
              /**
               * @title Blacklistable Token
               * @dev Allows accounts to be blacklisted by a "blacklister" role
               */
              abstract contract Blacklistable is Ownable {
                  address public blacklister;
                  mapping(address => bool) internal _deprecatedBlacklisted;
                  event Blacklisted(address indexed _account);
                  event UnBlacklisted(address indexed _account);
                  event BlacklisterChanged(address indexed newBlacklister);
                  /**
                   * @dev Throws if called by any account other than the blacklister.
                   */
                  modifier onlyBlacklister() {
                      require(
                          msg.sender == blacklister,
                          "Blacklistable: caller is not the blacklister"
                      );
                      _;
                  }
                  /**
                   * @dev Throws if argument account is blacklisted.
                   * @param _account The address to check.
                   */
                  modifier notBlacklisted(address _account) {
                      require(
                          !_isBlacklisted(_account),
                          "Blacklistable: account is blacklisted"
                      );
                      _;
                  }
                  /**
                   * @notice Checks if account is blacklisted.
                   * @param _account The address to check.
                   * @return True if the account is blacklisted, false if the account is not blacklisted.
                   */
                  function isBlacklisted(address _account) external view returns (bool) {
                      return _isBlacklisted(_account);
                  }
                  /**
                   * @notice Adds account to blacklist.
                   * @param _account The address to blacklist.
                   */
                  function blacklist(address _account) external onlyBlacklister {
                      _blacklist(_account);
                      emit Blacklisted(_account);
                  }
                  /**
                   * @notice Removes account from blacklist.
                   * @param _account The address to remove from the blacklist.
                   */
                  function unBlacklist(address _account) external onlyBlacklister {
                      _unBlacklist(_account);
                      emit UnBlacklisted(_account);
                  }
                  /**
                   * @notice Updates the blacklister address.
                   * @param _newBlacklister The address of the new blacklister.
                   */
                  function updateBlacklister(address _newBlacklister) external onlyOwner {
                      require(
                          _newBlacklister != address(0),
                          "Blacklistable: new blacklister is the zero address"
                      );
                      blacklister = _newBlacklister;
                      emit BlacklisterChanged(blacklister);
                  }
                  /**
                   * @dev Checks if account is blacklisted.
                   * @param _account The address to check.
                   * @return true if the account is blacklisted, false otherwise.
                   */
                  function _isBlacklisted(address _account)
                      internal
                      virtual
                      view
                      returns (bool);
                  /**
                   * @dev Helper method that blacklists an account.
                   * @param _account The address to blacklist.
                   */
                  function _blacklist(address _account) internal virtual;
                  /**
                   * @dev Helper method that unblacklists an account.
                   * @param _account The address to unblacklist.
                   */
                  function _unBlacklist(address _account) internal virtual;
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              abstract contract AbstractFiatTokenV1 is IERC20 {
                  function _approve(
                      address owner,
                      address spender,
                      uint256 value
                  ) internal virtual;
                  function _transfer(
                      address from,
                      address to,
                      uint256 value
                  ) internal virtual;
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { Ownable } from "../v1/Ownable.sol";
              import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
              import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
              contract Rescuable is Ownable {
                  using SafeERC20 for IERC20;
                  address private _rescuer;
                  event RescuerChanged(address indexed newRescuer);
                  /**
                   * @notice Returns current rescuer
                   * @return Rescuer's address
                   */
                  function rescuer() external view returns (address) {
                      return _rescuer;
                  }
                  /**
                   * @notice Revert if called by any account other than the rescuer.
                   */
                  modifier onlyRescuer() {
                      require(msg.sender == _rescuer, "Rescuable: caller is not the rescuer");
                      _;
                  }
                  /**
                   * @notice Rescue ERC20 tokens locked up in this contract.
                   * @param tokenContract ERC20 token contract address
                   * @param to        Recipient address
                   * @param amount    Amount to withdraw
                   */
                  function rescueERC20(
                      IERC20 tokenContract,
                      address to,
                      uint256 amount
                  ) external onlyRescuer {
                      tokenContract.safeTransfer(to, amount);
                  }
                  /**
                   * @notice Updates the rescuer address.
                   * @param newRescuer The address of the new rescuer.
                   */
                  function updateRescuer(address newRescuer) external onlyOwner {
                      require(
                          newRescuer != address(0),
                          "Rescuable: new rescuer is the zero address"
                      );
                      _rescuer = newRescuer;
                      emit RescuerChanged(newRescuer);
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { FiatTokenV1 } from "../v1/FiatTokenV1.sol";
              import { Rescuable } from "./Rescuable.sol";
              /**
               * @title FiatTokenV1_1
               * @dev ERC20 Token backed by fiat reserves
               */
              contract FiatTokenV1_1 is FiatTokenV1, Rescuable {
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              import { ECRecover } from "./ECRecover.sol";
              import { IERC1271 } from "../interface/IERC1271.sol";
              /**
               * @dev Signature verification helper that can be used instead of `ECRecover.recover` to seamlessly support both ECDSA
               * signatures from externally owned accounts (EOAs) as well as ERC1271 signatures from smart contract wallets.
               *
               * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/SignatureChecker.sol
               */
              library SignatureChecker {
                  /**
                   * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
                   * signature is validated against that smart contract using ERC1271, otherwise it's validated using `ECRecover.recover`.
                   * @param signer        Address of the claimed signer
                   * @param digest        Keccak-256 hash digest of the signed message
                   * @param signature     Signature byte array associated with hash
                   */
                  function isValidSignatureNow(
                      address signer,
                      bytes32 digest,
                      bytes memory signature
                  ) external view returns (bool) {
                      if (!isContract(signer)) {
                          return ECRecover.recover(digest, signature) == signer;
                      }
                      return isValidERC1271SignatureNow(signer, digest, signature);
                  }
                  /**
                   * @dev Checks if a signature is valid for a given signer and data hash. The signature is validated
                   * against the signer smart contract using ERC1271.
                   * @param signer        Address of the claimed signer
                   * @param digest        Keccak-256 hash digest of the signed message
                   * @param signature     Signature byte array associated with hash
                   *
                   * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
                   * change through time. It could return true at block N and false at block N+1 (or the opposite).
                   */
                  function isValidERC1271SignatureNow(
                      address signer,
                      bytes32 digest,
                      bytes memory signature
                  ) internal view returns (bool) {
                      (bool success, bytes memory result) = signer.staticcall(
                          abi.encodeWithSelector(
                              IERC1271.isValidSignature.selector,
                              digest,
                              signature
                          )
                      );
                      return (success &&
                          result.length >= 32 &&
                          abi.decode(result, (bytes32)) ==
                          bytes32(IERC1271.isValidSignature.selector));
                  }
                  /**
                   * @dev Checks if the input address is a smart contract.
                   */
                  function isContract(address addr) internal view returns (bool) {
                      uint256 size;
                      assembly {
                          size := extcodesize(addr)
                      }
                      return size > 0;
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              /**
               * @dev Signature message hash utilities for producing digests to be consumed by {ECDSA} recovery or signing.
               *
               * The library provides methods for generating a hash of a message that conforms to the
               * https://eips.ethereum.org/EIPS/eip-191[EIP 191] and https://eips.ethereum.org/EIPS/eip-712[EIP 712]
               * specifications.
               */
              library MessageHashUtils {
                  /**
                   * @dev Returns the keccak256 digest of an EIP-712 typed data (EIP-191 version `0x01`).
                   * Adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/21bb89ef5bfc789b9333eb05e3ba2b7b284ac77c/contracts/utils/cryptography/MessageHashUtils.sol
                   *
                   * The digest is calculated from a `domainSeparator` and a `structHash`, by prefixing them with
                   * `\\x19\\x01` and hashing the result. It corresponds to the hash signed by the
                   * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`] JSON-RPC method as part of EIP-712.
                   *
                   * @param domainSeparator    Domain separator
                   * @param structHash         Hashed EIP-712 data struct
                   * @return digest            The keccak256 digest of an EIP-712 typed data
                   */
                  function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash)
                      internal
                      pure
                      returns (bytes32 digest)
                  {
                      assembly {
                          let ptr := mload(0x40)
                          mstore(ptr, "\\x19\\x01")
                          mstore(add(ptr, 0x02), domainSeparator)
                          mstore(add(ptr, 0x22), structHash)
                          digest := keccak256(ptr, 0x42)
                      }
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              /**
               * @title EIP712
               * @notice A library that provides EIP712 helper functions
               */
              library EIP712 {
                  /**
                   * @notice Make EIP712 domain separator
                   * @param name      Contract name
                   * @param version   Contract version
                   * @param chainId   Blockchain ID
                   * @return Domain separator
                   */
                  function makeDomainSeparator(
                      string memory name,
                      string memory version,
                      uint256 chainId
                  ) internal view returns (bytes32) {
                      return
                          keccak256(
                              abi.encode(
                                  // keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
                                  0x8b73c3c69bb8fe3d512ecc4cf759cc79239f7b179b0ffacaa9a75d522b39400f,
                                  keccak256(bytes(name)),
                                  keccak256(bytes(version)),
                                  chainId,
                                  address(this)
                              )
                          );
                  }
                  /**
                   * @notice Make EIP712 domain separator
                   * @param name      Contract name
                   * @param version   Contract version
                   * @return Domain separator
                   */
                  function makeDomainSeparator(string memory name, string memory version)
                      internal
                      view
                      returns (bytes32)
                  {
                      uint256 chainId;
                      assembly {
                          chainId := chainid()
                      }
                      return makeDomainSeparator(name, version, chainId);
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              /**
               * @title ECRecover
               * @notice A library that provides a safe ECDSA recovery function
               */
              library ECRecover {
                  /**
                   * @notice Recover signer's address from a signed message
                   * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/65e4ffde586ec89af3b7e9140bdc9235d1254853/contracts/cryptography/ECDSA.sol
                   * Modifications: Accept v, r, and s as separate arguments
                   * @param digest    Keccak-256 hash digest of the signed message
                   * @param v         v of the signature
                   * @param r         r of the signature
                   * @param s         s of the signature
                   * @return Signer address
                   */
                  function recover(
                      bytes32 digest,
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  ) internal pure returns (address) {
                      // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                      // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                      // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                      // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                      //
                      // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                      // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                      // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                      // these malleable signatures as well.
                      if (
                          uint256(s) >
                          0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0
                      ) {
                          revert("ECRecover: invalid signature 's' value");
                      }
                      if (v != 27 && v != 28) {
                          revert("ECRecover: invalid signature 'v' value");
                      }
                      // If the signature is valid (and not malleable), return the signer address
                      address signer = ecrecover(digest, v, r, s);
                      require(signer != address(0), "ECRecover: invalid signature");
                      return signer;
                  }
                  /**
                   * @notice Recover signer's address from a signed message
                   * @dev Adapted from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0053ee040a7ff1dbc39691c9e67a69f564930a88/contracts/utils/cryptography/ECDSA.sol
                   * @param digest    Keccak-256 hash digest of the signed message
                   * @param signature Signature byte array associated with hash
                   * @return Signer address
                   */
                  function recover(bytes32 digest, bytes memory signature)
                      internal
                      pure
                      returns (address)
                  {
                      require(signature.length == 65, "ECRecover: invalid signature length");
                      bytes32 r;
                      bytes32 s;
                      uint8 v;
                      // ecrecover takes the signature parameters, and the only way to get them
                      // currently is to use assembly.
                      /// @solidity memory-safe-assembly
                      assembly {
                          r := mload(add(signature, 0x20))
                          s := mload(add(signature, 0x40))
                          v := byte(0, mload(add(signature, 0x60)))
                      }
                      return recover(digest, v, r, s);
                  }
              }
              /**
               * SPDX-License-Identifier: Apache-2.0
               *
               * Copyright (c) 2023, Circle Internet Financial, LLC.
               *
               * Licensed under the Apache License, Version 2.0 (the "License");
               * you may not use this file except in compliance with the License.
               * You may obtain a copy of the License at
               *
               * http://www.apache.org/licenses/LICENSE-2.0
               *
               * Unless required by applicable law or agreed to in writing, software
               * distributed under the License is distributed on an "AS IS" BASIS,
               * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
               * See the License for the specific language governing permissions and
               * limitations under the License.
               */
              pragma solidity 0.6.12;
              /**
               * @dev Interface of the ERC1271 standard signature validation method for
               * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
               */
              interface IERC1271 {
                  /**
                   * @dev Should return whether the signature provided is valid for the provided data
                   * @param hash          Hash of the data to be signed
                   * @param signature     Signature byte array associated with the provided data hash
                   * @return magicValue   bytes4 magic value 0x1626ba7e when function passes
                   */
                  function isValidSignature(bytes32 hash, bytes memory signature)
                      external
                      view
                      returns (bytes4 magicValue);
              }