ETH Price: $2,427.79 (+7.91%)

Transaction Decoder

Block:
21227025 at Nov-20-2024 06:01:11 AM +UTC
Transaction Fee:
0.001030109002101258 ETH $2.50
Gas Used:
112,286 Gas / 9.173975403 Gwei

Emitted Events:

387 FiatTokenProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x00000000000000000000000000c30f18033ebf454fd4024b47351615916b1e2b, 0x0000000000000000000000001a430f17c1dfc7b03f27e865fdae1f423620c5db, 0000000000000000000000000000000000000000000000000000000011e1e92a )
388 ERC20ConversionProxy.0x9f16cbcc523c67a60c450e5ffe4f3b7b6dbe772e7abcadb2686ce029a9a0a2b6( 0x9f16cbcc523c67a60c450e5ffe4f3b7b6dbe772e7abcadb2686ce029a9a0a2b6, 0x5ae17d820b742f0e3158207a2e3864c81a315adce9c36da58681b9dc51e8ad29, 000000000000000000000000a0b86991c6218b36c1d19d4a2e9eb0ce3606eb48, 0000000000000000000000001a430f17c1dfc7b03f27e865fdae1f423620c5db, 0000000000000000000000000000000000000000000000000000000011e1e92a, 0000000000000000000000000000000000000000000000000000000000000000, 00000000000000000000000035d0e078755cd84d3e0656caab417dee1d7939c7 )
389 ERC20ConversionProxy.TransferWithConversionAndReference( 0x96d0d1d75923f40b50f6fe74613b2c23239149607848fbca3941fee7ac041cdc, 0x5ae17d820b742f0e3158207a2e3864c81a315adce9c36da58681b9dc51e8ad29, 00000000000000000000000000000000000000000000000000000006fc23ac00, 000000000000000000000000775eb53d00dd0acd3ec1696472105d579b9b386b, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
0x00C30F18...5916b1e2b
0.470481421095017601 Eth
Nonce: 222
0.469451312092916343 Eth
Nonce: 223
0.001030109002101258
(beaverbuild)
5.082511829644691912 Eth5.082619390403344142 Eth0.00010756075865223
0xA0b86991...E3606eB48

Execution Trace

ERC20ConversionProxy.transferFromWithReferenceAndFee( _to=0x1A430F17C1dfc7B03F27E865fdAe1F423620c5db, _requestAmount=30000000000, _path=[0x775EB53d00DD0Acd3EC1696472105d579B9b386b, 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48], _paymentReference=0x42FDA700642801AB, _feeAmount=0, _feeAddress=0x35d0e078755Cd84D3E0656cAaB417Dee1d7939c7, _maxToSpend=303018141, _maxRateTimespan=0 )
  • ChainlinkConversionPath.getRate( _path=[0x775EB53d00DD0Acd3EC1696472105d579B9b386b, 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48] ) => ( rate=10000598735846315, oldestRateTimestamp=1732003235, decimals=1000000000000000000 )
    • FiatTokenProxy.STATICCALL( )
      • FiatTokenV2_2.DELEGATECALL( )
      • EACAggregatorProxy.STATICCALL( )
        • AccessControlledOCR2Aggregator.STATICCALL( )
        • EACAggregatorProxy.STATICCALL( )
          • AccessControlledOCR2Aggregator.STATICCALL( )
          • EACAggregatorProxy.STATICCALL( )
            • AccessControlledOCR2Aggregator.STATICCALL( )
            • ERC20FeeProxy.transferFromWithReferenceAndFee( _tokenAddress=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48, _to=0x1A430F17C1dfc7B03F27E865fdAe1F423620c5db, _amount=300017962, _paymentReference=0x42FDA700642801AB, _feeAmount=0, _feeAddress=0x35d0e078755Cd84D3E0656cAaB417Dee1d7939c7 )
              • FiatTokenProxy.23b872dd( )
                • FiatTokenV2_2.transferFrom( from=0x00C30F18033EBf454Fd4024b47351615916b1e2b, to=0x1A430F17C1dfc7B03F27E865fdAe1F423620c5db, value=300017962 ) => ( True )
                  File 1 of 7: ERC20ConversionProxy
                  // SPDX-License-Identifier: MIT
                  pragma solidity ^0.5.0;
                  
                  
                  /**
                   * @dev Wrappers over Solidity's arithmetic operations with added overflow
                   * checks.
                   *
                   * Arithmetic operations in Solidity wrap on overflow. This can easily result
                   * in bugs, because programmers usually assume that an overflow raises an
                   * error, which is the standard behavior in high level programming languages.
                   * `SafeMath` restores this intuition by reverting the transaction when an
                   * operation overflows.
                   *
                   * Using this library instead of the unchecked operations eliminates an entire
                   * class of bugs, so it's recommended to use it always.
                   */
                  library SafeMath {
                      /**
                       * @dev Returns the addition of two unsigned integers, reverting on
                       * overflow.
                       *
                       * Counterpart to Solidity's `+` operator.
                       *
                       * Requirements:
                       *
                       * - Addition cannot overflow.
                       */
                      function add(uint256 a, uint256 b) internal pure returns (uint256) {
                          uint256 c = a + b;
                          require(c >= a, "SafeMath: addition overflow");
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the subtraction of two unsigned integers, reverting on
                       * overflow (when the result is negative).
                       *
                       * Counterpart to Solidity's `-` operator.
                       *
                       * Requirements:
                       *
                       * - Subtraction cannot overflow.
                       */
                      function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                          return sub(a, b, "SafeMath: subtraction overflow");
                      }
                  
                      /**
                       * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                       * overflow (when the result is negative).
                       *
                       * Counterpart to Solidity's `-` operator.
                       *
                       * Requirements:
                       *
                       * - Subtraction cannot overflow.
                       */
                      function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                          require(b <= a, errorMessage);
                          uint256 c = a - b;
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the multiplication of two unsigned integers, reverting on
                       * overflow.
                       *
                       * Counterpart to Solidity's `*` operator.
                       *
                       * Requirements:
                       *
                       * - Multiplication cannot overflow.
                       */
                      function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                          // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                          // benefit is lost if 'b' is also tested.
                          // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                          if (a == 0) {
                              return 0;
                          }
                  
                          uint256 c = a * b;
                          require(c / a == b, "SafeMath: multiplication overflow");
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the integer division of two unsigned integers. Reverts on
                       * division by zero. The result is rounded towards zero.
                       *
                       * Counterpart to Solidity's `/` operator. Note: this function uses a
                       * `revert` opcode (which leaves remaining gas untouched) while Solidity
                       * uses an invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function div(uint256 a, uint256 b) internal pure returns (uint256) {
                          return div(a, b, "SafeMath: division by zero");
                      }
                  
                      /**
                       * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
                       * division by zero. The result is rounded towards zero.
                       *
                       * Counterpart to Solidity's `/` operator. Note: this function uses a
                       * `revert` opcode (which leaves remaining gas untouched) while Solidity
                       * uses an invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                          require(b > 0, errorMessage);
                          uint256 c = a / b;
                          // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                       * Reverts when dividing by zero.
                       *
                       * Counterpart to Solidity's `%` operator. This function uses a `revert`
                       * opcode (which leaves remaining gas untouched) while Solidity uses an
                       * invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                          return mod(a, b, "SafeMath: modulo by zero");
                      }
                  
                      /**
                       * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                       * Reverts with custom message when dividing by zero.
                       *
                       * Counterpart to Solidity's `%` operator. This function uses a `revert`
                       * opcode (which leaves remaining gas untouched) while Solidity uses an
                       * invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                          require(b != 0, errorMessage);
                          return a % b;
                      }
                  }
                  
                  /**
                   * @title Roles
                   * @dev Library for managing addresses assigned to a Role.
                   */
                  library Roles {
                      struct Role {
                          mapping (address => bool) bearer;
                      }
                  
                      /**
                       * @dev give an account access to this role
                       */
                      function add(Role storage role, address account) internal {
                          require(account != address(0));
                          require(!has(role, account));
                  
                          role.bearer[account] = true;
                      }
                  
                      /**
                       * @dev remove an account's access to this role
                       */
                      function remove(Role storage role, address account) internal {
                          require(account != address(0));
                          require(has(role, account));
                  
                          role.bearer[account] = false;
                      }
                  
                      /**
                       * @dev check if an account has this role
                       * @return bool
                       */
                      function has(Role storage role, address account) internal view returns (bool) {
                          require(account != address(0));
                          return role.bearer[account];
                      }
                  }
                  
                  /**
                   * @title ChainlinkConversionPath
                   *
                   * @notice ChainlinkConversionPath is a contract allowing to compute conversion rate from a Chainlink aggretators
                   */
                  interface ChainlinkConversionPath {
                  
                  
                    /**
                    * @notice Computes the rate from a list of conversion
                    * @param _path List of addresses representing the currencies for the conversions
                    * @return rate the rate
                    * @return oldestRateTimestamp he oldest timestamp of the path
                    * @return decimals of the conversion rate
                    */
                    function getRate(
                      address[] calldata _path
                    )
                      external
                      view
                      returns (uint256 rate, uint256 oldestRateTimestamp, uint256 decimals);
                  }
                  
                  interface IERC20FeeProxy {
                    event TransferWithReferenceAndFee(
                      address tokenAddress,
                      address to,
                      uint256 amount,
                      bytes indexed paymentReference,
                      uint256 feeAmount,
                      address feeAddress
                    );
                  
                    function transferFromWithReferenceAndFee(
                      address _tokenAddress,
                      address _to,
                      uint256 _amount,
                      bytes calldata _paymentReference,
                      uint256 _feeAmount,
                      address _feeAddress
                      ) external;
                  }
                  
                  
                  /**
                   * @title ERC20ConversionProxy
                   */
                  contract ERC20ConversionProxy {
                    using SafeMath for uint256;
                  
                    address public paymentProxy;
                    ChainlinkConversionPath public chainlinkConversionPath;
                  
                    constructor(address _paymentProxyAddress, address _chainlinkConversionPathAddress) public {
                      paymentProxy = _paymentProxyAddress;
                      chainlinkConversionPath = ChainlinkConversionPath(_chainlinkConversionPathAddress);
                    }
                  
                    // Event to declare a transfer with a reference
                    event TransferWithConversionAndReference(
                      uint256 amount,
                      address currency,
                      bytes indexed paymentReference,
                      uint256 feeAmount,
                      uint256 maxRateTimespan
                    );
                  
                    /**
                     * @notice Performs an ERC20 token transfer with a reference computing the amount based on a fiat amount
                     * @param _to Transfer recipient
                     * @param _requestAmount request amount
                     * @param _path conversion path
                     * @param _paymentReference Reference of the payment related
                     * @param _feeAmount The amount of the payment fee
                     * @param _feeAddress The fee recipient
                     * @param _maxToSpend amount max that we can spend on the behalf of the user
                     * @param _maxRateTimespan max time span with the oldestrate, ignored if zero
                     */
                    function transferFromWithReferenceAndFee(
                      address _to,
                      uint256 _requestAmount,
                      address[] calldata _path,
                      bytes calldata _paymentReference,
                      uint256 _feeAmount,
                      address _feeAddress,
                      uint256 _maxToSpend,
                      uint256 _maxRateTimespan
                    ) external
                    {
                      (uint256 amountToPay, uint256 amountToPayInFees) = getConversions(_path, _requestAmount, _feeAmount, _maxRateTimespan);
                  
                      require(amountToPay.add(amountToPayInFees) <= _maxToSpend, "Amount to pay is over the user limit");
                  
                      // Pay the request and fees
                      (bool status, ) = paymentProxy.delegatecall(
                        abi.encodeWithSignature(
                          "transferFromWithReferenceAndFee(address,address,uint256,bytes,uint256,address)",
                          // payment currency
                          _path[_path.length - 1],
                          _to,
                          amountToPay,
                          _paymentReference,
                          amountToPayInFees,
                          _feeAddress
                        )
                      );
                      require(status, "transferFromWithReferenceAndFee failed");
                  
                      // Event to declare a transfer with a reference
                      emit TransferWithConversionAndReference(
                        _requestAmount,
                        // request currency
                        _path[0],
                        _paymentReference,
                        _feeAmount,
                        _maxRateTimespan
                      );
                    }
                  
                    function getConversions(
                      address[] memory _path,
                      uint256 _requestAmount,
                      uint256 _feeAmount,
                      uint256 _maxRateTimespan
                    ) internal
                      view
                      returns (uint256 amountToPay, uint256 amountToPayInFees)
                    {
                      (uint256 rate, uint256 oldestTimestampRate, uint256 decimals) = chainlinkConversionPath.getRate(_path);
                  
                      // Check rate timespan
                      require(_maxRateTimespan == 0 || block.timestamp.sub(oldestTimestampRate) <= _maxRateTimespan, "aggregator rate is outdated");
                      
                      // Get the amount to pay in the crypto currency chosen
                      amountToPay = _requestAmount.mul(rate).div(decimals);
                      amountToPayInFees = _feeAmount.mul(rate).div(decimals);
                    }
                  }

                  File 2 of 7: 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 3 of 7: ChainlinkConversionPath
                  // SPDX-License-Identifier: MIT
                  pragma solidity >=0.4.25 <0.7.0;
                  
                  /**
                   * @dev Wrappers over Solidity's arithmetic operations with added overflow
                   * checks.
                   *
                   * Arithmetic operations in Solidity wrap on overflow. This can easily result
                   * in bugs, because programmers usually assume that an overflow raises an
                   * error, which is the standard behavior in high level programming languages.
                   * `SafeMath` restores this intuition by reverting the transaction when an
                   * operation overflows.
                   *
                   * Using this library instead of the unchecked operations eliminates an entire
                   * class of bugs, so it's recommended to use it always.
                   */
                  library SafeMath {
                      /**
                       * @dev Returns the addition of two unsigned integers, reverting on
                       * overflow.
                       *
                       * Counterpart to Solidity's `+` operator.
                       *
                       * Requirements:
                       *
                       * - Addition cannot overflow.
                       */
                      function add(uint256 a, uint256 b) internal pure returns (uint256) {
                          uint256 c = a + b;
                          require(c >= a, "SafeMath: addition overflow");
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the subtraction of two unsigned integers, reverting on
                       * overflow (when the result is negative).
                       *
                       * Counterpart to Solidity's `-` operator.
                       *
                       * Requirements:
                       *
                       * - Subtraction cannot overflow.
                       */
                      function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                          return sub(a, b, "SafeMath: subtraction overflow");
                      }
                  
                      /**
                       * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
                       * overflow (when the result is negative).
                       *
                       * Counterpart to Solidity's `-` operator.
                       *
                       * Requirements:
                       *
                       * - Subtraction cannot overflow.
                       */
                      function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                          require(b <= a, errorMessage);
                          uint256 c = a - b;
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the multiplication of two unsigned integers, reverting on
                       * overflow.
                       *
                       * Counterpart to Solidity's `*` operator.
                       *
                       * Requirements:
                       *
                       * - Multiplication cannot overflow.
                       */
                      function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                          // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                          // benefit is lost if 'b' is also tested.
                          // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                          if (a == 0) {
                              return 0;
                          }
                  
                          uint256 c = a * b;
                          require(c / a == b, "SafeMath: multiplication overflow");
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the integer division of two unsigned integers. Reverts on
                       * division by zero. The result is rounded towards zero.
                       *
                       * Counterpart to Solidity's `/` operator. Note: this function uses a
                       * `revert` opcode (which leaves remaining gas untouched) while Solidity
                       * uses an invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function div(uint256 a, uint256 b) internal pure returns (uint256) {
                          return div(a, b, "SafeMath: division by zero");
                      }
                  
                      /**
                       * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
                       * division by zero. The result is rounded towards zero.
                       *
                       * Counterpart to Solidity's `/` operator. Note: this function uses a
                       * `revert` opcode (which leaves remaining gas untouched) while Solidity
                       * uses an invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                          require(b > 0, errorMessage);
                          uint256 c = a / b;
                          // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                  
                          return c;
                      }
                  
                      /**
                       * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                       * Reverts when dividing by zero.
                       *
                       * Counterpart to Solidity's `%` operator. This function uses a `revert`
                       * opcode (which leaves remaining gas untouched) while Solidity uses an
                       * invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                          return mod(a, b, "SafeMath: modulo by zero");
                      }
                  
                      /**
                       * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
                       * Reverts with custom message when dividing by zero.
                       *
                       * Counterpart to Solidity's `%` operator. This function uses a `revert`
                       * opcode (which leaves remaining gas untouched) while Solidity uses an
                       * invalid opcode to revert (consuming all remaining gas).
                       *
                       * Requirements:
                       *
                       * - The divisor cannot be zero.
                       */
                      function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                          require(b != 0, errorMessage);
                          return a % b;
                      }
                  }
                  
                  /**
                   * @title Roles
                   * @dev Library for managing addresses assigned to a Role.
                   */
                  library Roles {
                      struct Role {
                          mapping (address => bool) bearer;
                      }
                  
                      /**
                       * @dev give an account access to this role
                       */
                      function add(Role storage role, address account) internal {
                          require(account != address(0));
                          require(!has(role, account));
                  
                          role.bearer[account] = true;
                      }
                  
                      /**
                       * @dev remove an account's access to this role
                       */
                      function remove(Role storage role, address account) internal {
                          require(account != address(0));
                          require(has(role, account));
                  
                          role.bearer[account] = false;
                      }
                  
                      /**
                       * @dev check if an account has this role
                       * @return bool
                       */
                      function has(Role storage role, address account) internal view returns (bool) {
                          require(account != address(0));
                          return role.bearer[account];
                      }
                  }
                  
                  
                  /**
                   * @title WhitelistAdminRole
                   * @dev WhitelistAdmins are responsible for assigning and removing Whitelisted accounts.
                   */
                  contract WhitelistAdminRole {
                      using Roles for Roles.Role;
                  
                      event WhitelistAdminAdded(address indexed account);
                      event WhitelistAdminRemoved(address indexed account);
                  
                      Roles.Role private _whitelistAdmins;
                  
                      constructor () internal {
                          _addWhitelistAdmin(msg.sender);
                      }
                  
                      modifier onlyWhitelistAdmin() {
                          require(isWhitelistAdmin(msg.sender));
                          _;
                      }
                  
                      function isWhitelistAdmin(address account) public view returns (bool) {
                          return _whitelistAdmins.has(account);
                      }
                  
                      function addWhitelistAdmin(address account) public onlyWhitelistAdmin {
                          _addWhitelistAdmin(account);
                      }
                  
                      function renounceWhitelistAdmin() public {
                          _removeWhitelistAdmin(msg.sender);
                      }
                  
                      function _addWhitelistAdmin(address account) internal {
                          _whitelistAdmins.add(account);
                          emit WhitelistAdminAdded(account);
                      }
                  
                      function _removeWhitelistAdmin(address account) internal {
                          _whitelistAdmins.remove(account);
                          emit WhitelistAdminRemoved(account);
                      }
                  }
                  
                  interface ERC20fraction {
                    function decimals() external view returns (uint8);
                  }
                  
                  interface AggregatorFraction {
                    function decimals() external view returns (uint8);
                    function latestAnswer() external view returns (int256);
                    function latestTimestamp() external view returns (uint256);
                  }
                  
                  
                  /**
                   * @title ChainlinkConversionPath
                   *
                   * @notice ChainlinkConversionPath is a contract computing currency conversion rates based on Chainlink aggretators
                   */
                  contract ChainlinkConversionPath is WhitelistAdminRole {
                    using SafeMath for uint256;
                  
                    uint constant DECIMALS = 1e18;
                  
                    // Mapping of Chainlink aggregators (input currency => output currency => contract address)
                    // input & output currencies are the addresses of the ERC20 contracts OR the sha3("currency code")
                    mapping(address => mapping(address => address)) public allAggregators;
                  
                    // declare a new aggregator
                    event AggregatorUpdated(address _input, address _output, address _aggregator);
                  
                    /**
                      * @notice Update an aggregator
                      * @param _input address representing the input currency
                      * @param _output address representing the output currency
                      * @param _aggregator address of the aggregator contract
                    */
                    function updateAggregator(address _input, address _output, address _aggregator)
                      external
                      onlyWhitelistAdmin
                    {
                      allAggregators[_input][_output] = _aggregator;
                      emit AggregatorUpdated(_input, _output, _aggregator);
                    }
                  
                    /**
                      * @notice Update a list of aggregators
                      * @param _inputs list of addresses representing the input currencies
                      * @param _outputs list of addresses representing the output currencies
                      * @param _aggregators list of addresses of the aggregator contracts
                    */
                    function updateAggregatorsList(address[] calldata _inputs, address[] calldata _outputs, address[] calldata _aggregators)
                      external
                      onlyWhitelistAdmin
                    {
                      require(_inputs.length == _outputs.length, "arrays must have the same length");
                      require(_inputs.length == _aggregators.length, "arrays must have the same length");
                  
                      // For every conversions of the path
                      for (uint i; i < _inputs.length; i++) {
                        allAggregators[_inputs[i]][_outputs[i]] = _aggregators[i];
                        emit AggregatorUpdated(_inputs[i], _outputs[i], _aggregators[i]);
                      }
                    }
                  
                    /**
                    * @notice Computes the conversion of an amount through a list of intermediate conversions
                    * @param _amountIn Amount to convert
                    * @param _path List of addresses representing the currencies for the intermediate conversions
                    * @return result The result after all the conversions
                    * @return oldestRateTimestamp The oldest timestamp of the path
                    */
                    function getConversion(
                      uint256 _amountIn,
                      address[] calldata _path
                    )
                      external
                      view
                      returns (uint256 result, uint256 oldestRateTimestamp)
                    {
                      (uint256 rate, uint256 timestamp, uint256 decimals) = getRate(_path);
                  
                      // initialize the result
                      result = _amountIn.mul(rate).div(decimals);
                  
                      oldestRateTimestamp = timestamp;
                    }
                  
                    /**
                    * @notice Computes the conversion rate from a list of currencies
                    * @param _path List of addresses representing the currencies for the conversions
                    * @return rate The rate
                    * @return oldestRateTimestamp The oldest timestamp of the path
                    * @return decimals of the conversion rate
                    */
                    function getRate(
                      address[] memory _path
                    )
                      public
                      view
                      returns (uint256 rate, uint256 oldestRateTimestamp, uint256 decimals)
                    {
                      // initialize the result with 18 decimals (for more precision)
                      rate = DECIMALS;
                      decimals = DECIMALS;
                      oldestRateTimestamp = block.timestamp;
                  
                      // For every conversion of the path
                      for (uint i; i < _path.length - 1; i++) {
                        (AggregatorFraction aggregator, bool reverseAggregator, uint256 decimalsInput, uint256 decimalsOutput) = getAggregatorAndDecimals(_path[i], _path[i + 1]);
                  
                        // store the latest timestamp of the path
                        uint256 currentTimestamp = aggregator.latestTimestamp();
                        if (currentTimestamp < oldestRateTimestamp) {
                          oldestRateTimestamp = currentTimestamp;
                        }
                  
                        // get the rate of the current step
                        uint256 currentRate = uint256(aggregator.latestAnswer());
                        // get the number of decimals of the current rate
                        uint256 decimalsAggregator = uint256(aggregator.decimals());
                  
                        // mul with the difference of decimals before the current rate computation (for more precision)
                        if (decimalsAggregator > decimalsInput) {
                          rate = rate.mul(10**(decimalsAggregator-decimalsInput));
                        }
                        if (decimalsAggregator < decimalsOutput) {
                          rate = rate.mul(10**(decimalsOutput-decimalsAggregator));
                        }
                  
                        // Apply the current rate (if path uses an aggregator in the reverse way, div instead of mul)
                        if (reverseAggregator) {
                          rate = rate.mul(10**decimalsAggregator).div(currentRate);
                        } else {
                          rate = rate.mul(currentRate).div(10**decimalsAggregator);
                        }
                  
                        // div with the difference of decimals AFTER the current rate computation (for more precision)
                        if (decimalsAggregator < decimalsInput) {
                          rate = rate.div(10**(decimalsInput-decimalsAggregator));
                        }
                        if (decimalsAggregator > decimalsOutput) {
                          rate = rate.div(10**(decimalsAggregator-decimalsOutput));
                        }
                      }
                    }
                  
                    /**
                    * @notice Gets aggregators and decimals of two currencies
                    * @param _input input Address
                    * @param _output output Address
                    * @return aggregator to get the rate between the two currencies
                    * @return reverseAggregator true if the aggregator returned give the rate from _output to _input
                    * @return decimalsInput decimals of _input
                    * @return decimalsOutput decimals of _output
                    */
                    function getAggregatorAndDecimals(address _input, address _output)
                      private
                      view
                      returns (AggregatorFraction aggregator, bool reverseAggregator, uint256 decimalsInput, uint256 decimalsOutput)
                    {
                      // Try to get the right aggregator for the conversion
                      aggregator = AggregatorFraction(allAggregators[_input][_output]);
                      reverseAggregator = false;
                  
                      // if no aggregator found we try to find an aggregator in the reverse way
                      if (address(aggregator) == address(0x00)) {
                        aggregator = AggregatorFraction(allAggregators[_output][_input]);
                        reverseAggregator = true;
                      }
                  
                      require(address(aggregator) != address(0x00), "No aggregator found");
                  
                      // get the decimals for the two currencies
                      decimalsInput = getDecimals(_input);
                      decimalsOutput = getDecimals(_output);
                    }
                  
                    /**
                    * @notice Gets decimals from an address currency
                    * @param _addr address to check
                    * @return decimals number of decimals
                    */
                    function getDecimals(address _addr)
                      private
                      view
                      returns (uint256 decimals)
                    {
                      // by default we assume it is FIAT so 8 decimals
                      decimals = 8;
                      // if address is the hash of the ETH currency
                      if (_addr == address(0xF5AF88e117747e87fC5929F2ff87221B1447652E)) {
                        decimals = 18;
                      } else if (isContract(_addr)) {
                        // otherwise, we get the decimals from the erc20 directly
                        decimals = ERC20fraction(_addr).decimals();
                      }
                    }
                  
                    /**
                    * @notice Checks if an address is a contract
                    * @param _addr Address to check
                    * @return true if the address hosts a contract, false otherwise
                    */
                    function isContract(address _addr)
                      private
                      view
                      returns (bool)
                    {
                      uint32 size;
                      // solium-disable security/no-inline-assembly
                      assembly {
                        size := extcodesize(_addr)
                      }
                      return (size > 0);
                    }
                  }

                  File 4 of 7: 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);
                  }
                  

                  File 5 of 7: EACAggregatorProxy
                  /**
                   *Submitted for verification at Etherscan.io on 2020-09-29
                  */
                  
                  pragma solidity 0.6.6;
                  
                  
                  /**
                   * @title The Owned contract
                   * @notice A contract with helpers for basic contract ownership.
                   */
                  contract Owned {
                  
                    address public owner;
                    address private pendingOwner;
                  
                    event OwnershipTransferRequested(
                      address indexed from,
                      address indexed to
                    );
                    event OwnershipTransferred(
                      address indexed from,
                      address indexed to
                    );
                  
                    constructor() public {
                      owner = msg.sender;
                    }
                  
                    /**
                     * @dev Allows an owner to begin transferring ownership to a new address,
                     * pending.
                     */
                    function transferOwnership(address _to)
                      external
                      onlyOwner()
                    {
                      pendingOwner = _to;
                  
                      emit OwnershipTransferRequested(owner, _to);
                    }
                  
                    /**
                     * @dev Allows an ownership transfer to be completed by the recipient.
                     */
                    function acceptOwnership()
                      external
                    {
                      require(msg.sender == pendingOwner, "Must be proposed owner");
                  
                      address oldOwner = owner;
                      owner = msg.sender;
                      pendingOwner = address(0);
                  
                      emit OwnershipTransferred(oldOwner, msg.sender);
                    }
                  
                    /**
                     * @dev Reverts if called by anyone other than the contract owner.
                     */
                    modifier onlyOwner() {
                      require(msg.sender == owner, "Only callable by owner");
                      _;
                    }
                  
                  }
                  
                  interface AggregatorInterface {
                    function latestAnswer() external view returns (int256);
                    function latestTimestamp() external view returns (uint256);
                    function latestRound() external view returns (uint256);
                    function getAnswer(uint256 roundId) external view returns (int256);
                    function getTimestamp(uint256 roundId) external view returns (uint256);
                  
                    event AnswerUpdated(int256 indexed current, uint256 indexed roundId, uint256 updatedAt);
                    event NewRound(uint256 indexed roundId, address indexed startedBy, uint256 startedAt);
                  }
                  
                  interface AggregatorV3Interface {
                  
                    function decimals() external view returns (uint8);
                    function description() external view returns (string memory);
                    function version() external view returns (uint256);
                  
                    // getRoundData and latestRoundData should both raise "No data present"
                    // if they do not have data to report, instead of returning unset values
                    // which could be misinterpreted as actual reported values.
                    function getRoundData(uint80 _roundId)
                      external
                      view
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      );
                    function latestRoundData()
                      external
                      view
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      );
                  
                  }
                  
                  interface AggregatorV2V3Interface is AggregatorInterface, AggregatorV3Interface
                  {
                  }
                  
                  /**
                   * @title A trusted proxy for updating where current answers are read from
                   * @notice This contract provides a consistent address for the
                   * CurrentAnwerInterface but delegates where it reads from to the owner, who is
                   * trusted to update it.
                   */
                  contract AggregatorProxy is AggregatorV2V3Interface, Owned {
                  
                    struct Phase {
                      uint16 id;
                      AggregatorV2V3Interface aggregator;
                    }
                    Phase private currentPhase;
                    AggregatorV2V3Interface public proposedAggregator;
                    mapping(uint16 => AggregatorV2V3Interface) public phaseAggregators;
                  
                    uint256 constant private PHASE_OFFSET = 64;
                    uint256 constant private PHASE_SIZE = 16;
                    uint256 constant private MAX_ID = 2**(PHASE_OFFSET+PHASE_SIZE) - 1;
                  
                    constructor(address _aggregator) public Owned() {
                      setAggregator(_aggregator);
                    }
                  
                    /**
                     * @notice Reads the current answer from aggregator delegated to.
                     *
                     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended latestRoundData
                     * instead which includes better verification information.
                     */
                    function latestAnswer()
                      public
                      view
                      virtual
                      override
                      returns (int256 answer)
                    {
                      return currentPhase.aggregator.latestAnswer();
                    }
                  
                    /**
                     * @notice Reads the last updated height from aggregator delegated to.
                     *
                     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended latestRoundData
                     * instead which includes better verification information.
                     */
                    function latestTimestamp()
                      public
                      view
                      virtual
                      override
                      returns (uint256 updatedAt)
                    {
                      return currentPhase.aggregator.latestTimestamp();
                    }
                  
                    /**
                     * @notice get past rounds answers
                     * @param _roundId the answer number to retrieve the answer for
                     *
                     * @dev #[deprecated] Use getRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended getRoundData
                     * instead which includes better verification information.
                     */
                    function getAnswer(uint256 _roundId)
                      public
                      view
                      virtual
                      override
                      returns (int256 answer)
                    {
                      if (_roundId > MAX_ID) return 0;
                  
                      (uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
                      AggregatorV2V3Interface aggregator = phaseAggregators[phaseId];
                      if (address(aggregator) == address(0)) return 0;
                  
                      return aggregator.getAnswer(aggregatorRoundId);
                    }
                  
                    /**
                     * @notice get block timestamp when an answer was last updated
                     * @param _roundId the answer number to retrieve the updated timestamp for
                     *
                     * @dev #[deprecated] Use getRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended getRoundData
                     * instead which includes better verification information.
                     */
                    function getTimestamp(uint256 _roundId)
                      public
                      view
                      virtual
                      override
                      returns (uint256 updatedAt)
                    {
                      if (_roundId > MAX_ID) return 0;
                  
                      (uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
                      AggregatorV2V3Interface aggregator = phaseAggregators[phaseId];
                      if (address(aggregator) == address(0)) return 0;
                  
                      return aggregator.getTimestamp(aggregatorRoundId);
                    }
                  
                    /**
                     * @notice get the latest completed round where the answer was updated. This
                     * ID includes the proxy's phase, to make sure round IDs increase even when
                     * switching to a newly deployed aggregator.
                     *
                     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended latestRoundData
                     * instead which includes better verification information.
                     */
                    function latestRound()
                      public
                      view
                      virtual
                      override
                      returns (uint256 roundId)
                    {
                      Phase memory phase = currentPhase; // cache storage reads
                      return addPhase(phase.id, uint64(phase.aggregator.latestRound()));
                    }
                  
                    /**
                     * @notice get data about a round. Consumers are encouraged to check
                     * that they're receiving fresh data by inspecting the updatedAt and
                     * answeredInRound return values.
                     * Note that different underlying implementations of AggregatorV3Interface
                     * have slightly different semantics for some of the return values. Consumers
                     * should determine what implementations they expect to receive
                     * data from and validate that they can properly handle return data from all
                     * of them.
                     * @param _roundId the requested round ID as presented through the proxy, this
                     * is made up of the aggregator's round ID with the phase ID encoded in the
                     * two highest order bytes
                     * @return roundId is the round ID from the aggregator for which the data was
                     * retrieved combined with an phase to ensure that round IDs get larger as
                     * time moves forward.
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @dev Note that answer and updatedAt may change between queries.
                     */
                    function getRoundData(uint80 _roundId)
                      public
                      view
                      virtual
                      override
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      (uint16 phaseId, uint64 aggregatorRoundId) = parseIds(_roundId);
                  
                      (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 ansIn
                      ) = phaseAggregators[phaseId].getRoundData(aggregatorRoundId);
                  
                      return addPhaseIds(roundId, answer, startedAt, updatedAt, ansIn, phaseId);
                    }
                  
                    /**
                     * @notice get data about the latest round. Consumers are encouraged to check
                     * that they're receiving fresh data by inspecting the updatedAt and
                     * answeredInRound return values.
                     * Note that different underlying implementations of AggregatorV3Interface
                     * have slightly different semantics for some of the return values. Consumers
                     * should determine what implementations they expect to receive
                     * data from and validate that they can properly handle return data from all
                     * of them.
                     * @return roundId is the round ID from the aggregator for which the data was
                     * retrieved combined with an phase to ensure that round IDs get larger as
                     * time moves forward.
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @dev Note that answer and updatedAt may change between queries.
                     */
                    function latestRoundData()
                      public
                      view
                      virtual
                      override
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      Phase memory current = currentPhase; // cache storage reads
                  
                      (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 ansIn
                      ) = current.aggregator.latestRoundData();
                  
                      return addPhaseIds(roundId, answer, startedAt, updatedAt, ansIn, current.id);
                    }
                  
                    /**
                     * @notice Used if an aggregator contract has been proposed.
                     * @param _roundId the round ID to retrieve the round data for
                     * @return roundId is the round ID for which data was retrieved
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                    */
                    function proposedGetRoundData(uint80 _roundId)
                      public
                      view
                      virtual
                      hasProposal()
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      return proposedAggregator.getRoundData(_roundId);
                    }
                  
                    /**
                     * @notice Used if an aggregator contract has been proposed.
                     * @return roundId is the round ID for which data was retrieved
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                    */
                    function proposedLatestRoundData()
                      public
                      view
                      virtual
                      hasProposal()
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      return proposedAggregator.latestRoundData();
                    }
                  
                    /**
                     * @notice returns the current phase's aggregator address.
                     */
                    function aggregator()
                      external
                      view
                      returns (address)
                    {
                      return address(currentPhase.aggregator);
                    }
                  
                    /**
                     * @notice returns the current phase's ID.
                     */
                    function phaseId()
                      external
                      view
                      returns (uint16)
                    {
                      return currentPhase.id;
                    }
                  
                    /**
                     * @notice represents the number of decimals the aggregator responses represent.
                     */
                    function decimals()
                      external
                      view
                      override
                      returns (uint8)
                    {
                      return currentPhase.aggregator.decimals();
                    }
                  
                    /**
                     * @notice the version number representing the type of aggregator the proxy
                     * points to.
                     */
                    function version()
                      external
                      view
                      override
                      returns (uint256)
                    {
                      return currentPhase.aggregator.version();
                    }
                  
                    /**
                     * @notice returns the description of the aggregator the proxy points to.
                     */
                    function description()
                      external
                      view
                      override
                      returns (string memory)
                    {
                      return currentPhase.aggregator.description();
                    }
                  
                    /**
                     * @notice Allows the owner to propose a new address for the aggregator
                     * @param _aggregator The new address for the aggregator contract
                     */
                    function proposeAggregator(address _aggregator)
                      external
                      onlyOwner()
                    {
                      proposedAggregator = AggregatorV2V3Interface(_aggregator);
                    }
                  
                    /**
                     * @notice Allows the owner to confirm and change the address
                     * to the proposed aggregator
                     * @dev Reverts if the given address doesn't match what was previously
                     * proposed
                     * @param _aggregator The new address for the aggregator contract
                     */
                    function confirmAggregator(address _aggregator)
                      external
                      onlyOwner()
                    {
                      require(_aggregator == address(proposedAggregator), "Invalid proposed aggregator");
                      delete proposedAggregator;
                      setAggregator(_aggregator);
                    }
                  
                  
                    /*
                     * Internal
                     */
                  
                    function setAggregator(address _aggregator)
                      internal
                    {
                      uint16 id = currentPhase.id + 1;
                      currentPhase = Phase(id, AggregatorV2V3Interface(_aggregator));
                      phaseAggregators[id] = AggregatorV2V3Interface(_aggregator);
                    }
                  
                    function addPhase(
                      uint16 _phase,
                      uint64 _originalId
                    )
                      internal
                      view
                      returns (uint80)
                    {
                      return uint80(uint256(_phase) << PHASE_OFFSET | _originalId);
                    }
                  
                    function parseIds(
                      uint256 _roundId
                    )
                      internal
                      view
                      returns (uint16, uint64)
                    {
                      uint16 phaseId = uint16(_roundId >> PHASE_OFFSET);
                      uint64 aggregatorRoundId = uint64(_roundId);
                  
                      return (phaseId, aggregatorRoundId);
                    }
                  
                    function addPhaseIds(
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound,
                        uint16 phaseId
                    )
                      internal
                      view
                      returns (uint80, int256, uint256, uint256, uint80)
                    {
                      return (
                        addPhase(phaseId, uint64(roundId)),
                        answer,
                        startedAt,
                        updatedAt,
                        addPhase(phaseId, uint64(answeredInRound))
                      );
                    }
                  
                    /*
                     * Modifiers
                     */
                  
                    modifier hasProposal() {
                      require(address(proposedAggregator) != address(0), "No proposed aggregator present");
                      _;
                    }
                  
                  }
                  
                  interface AccessControllerInterface {
                    function hasAccess(address user, bytes calldata data) external view returns (bool);
                  }
                  
                  /**
                   * @title External Access Controlled Aggregator Proxy
                   * @notice A trusted proxy for updating where current answers are read from
                   * @notice This contract provides a consistent address for the
                   * Aggregator and AggregatorV3Interface but delegates where it reads from to the owner, who is
                   * trusted to update it.
                   * @notice Only access enabled addresses are allowed to access getters for
                   * aggregated answers and round information.
                   */
                  contract EACAggregatorProxy is AggregatorProxy {
                  
                    AccessControllerInterface public accessController;
                  
                    constructor(
                      address _aggregator,
                      address _accessController
                    )
                      public
                      AggregatorProxy(_aggregator)
                    {
                      setController(_accessController);
                    }
                  
                    /**
                     * @notice Allows the owner to update the accessController contract address.
                     * @param _accessController The new address for the accessController contract
                     */
                    function setController(address _accessController)
                      public
                      onlyOwner()
                    {
                      accessController = AccessControllerInterface(_accessController);
                    }
                  
                    /**
                     * @notice Reads the current answer from aggregator delegated to.
                     * @dev overridden function to add the checkAccess() modifier
                     *
                     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended latestRoundData
                     * instead which includes better verification information.
                     */
                    function latestAnswer()
                      public
                      view
                      override
                      checkAccess()
                      returns (int256)
                    {
                      return super.latestAnswer();
                    }
                  
                    /**
                     * @notice get the latest completed round where the answer was updated. This
                     * ID includes the proxy's phase, to make sure round IDs increase even when
                     * switching to a newly deployed aggregator.
                     *
                     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended latestRoundData
                     * instead which includes better verification information.
                     */
                    function latestTimestamp()
                      public
                      view
                      override
                      checkAccess()
                      returns (uint256)
                    {
                      return super.latestTimestamp();
                    }
                  
                    /**
                     * @notice get past rounds answers
                     * @param _roundId the answer number to retrieve the answer for
                     * @dev overridden function to add the checkAccess() modifier
                     *
                     * @dev #[deprecated] Use getRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended getRoundData
                     * instead which includes better verification information.
                     */
                    function getAnswer(uint256 _roundId)
                      public
                      view
                      override
                      checkAccess()
                      returns (int256)
                    {
                      return super.getAnswer(_roundId);
                    }
                  
                    /**
                     * @notice get block timestamp when an answer was last updated
                     * @param _roundId the answer number to retrieve the updated timestamp for
                     * @dev overridden function to add the checkAccess() modifier
                     *
                     * @dev #[deprecated] Use getRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended getRoundData
                     * instead which includes better verification information.
                     */
                    function getTimestamp(uint256 _roundId)
                      public
                      view
                      override
                      checkAccess()
                      returns (uint256)
                    {
                      return super.getTimestamp(_roundId);
                    }
                  
                    /**
                     * @notice get the latest completed round where the answer was updated
                     * @dev overridden function to add the checkAccess() modifier
                     *
                     * @dev #[deprecated] Use latestRoundData instead. This does not error if no
                     * answer has been reached, it will simply return 0. Either wait to point to
                     * an already answered Aggregator or use the recommended latestRoundData
                     * instead which includes better verification information.
                     */
                    function latestRound()
                      public
                      view
                      override
                      checkAccess()
                      returns (uint256)
                    {
                      return super.latestRound();
                    }
                  
                    /**
                     * @notice get data about a round. Consumers are encouraged to check
                     * that they're receiving fresh data by inspecting the updatedAt and
                     * answeredInRound return values.
                     * Note that different underlying implementations of AggregatorV3Interface
                     * have slightly different semantics for some of the return values. Consumers
                     * should determine what implementations they expect to receive
                     * data from and validate that they can properly handle return data from all
                     * of them.
                     * @param _roundId the round ID to retrieve the round data for
                     * @return roundId is the round ID from the aggregator for which the data was
                     * retrieved combined with a phase to ensure that round IDs get larger as
                     * time moves forward.
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @dev Note that answer and updatedAt may change between queries.
                     */
                    function getRoundData(uint80 _roundId)
                      public
                      view
                      checkAccess()
                      override
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      return super.getRoundData(_roundId);
                    }
                  
                    /**
                     * @notice get data about the latest round. Consumers are encouraged to check
                     * that they're receiving fresh data by inspecting the updatedAt and
                     * answeredInRound return values.
                     * Note that different underlying implementations of AggregatorV3Interface
                     * have slightly different semantics for some of the return values. Consumers
                     * should determine what implementations they expect to receive
                     * data from and validate that they can properly handle return data from all
                     * of them.
                     * @return roundId is the round ID from the aggregator for which the data was
                     * retrieved combined with a phase to ensure that round IDs get larger as
                     * time moves forward.
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @dev Note that answer and updatedAt may change between queries.
                     */
                    function latestRoundData()
                      public
                      view
                      checkAccess()
                      override
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      return super.latestRoundData();
                    }
                  
                    /**
                     * @notice Used if an aggregator contract has been proposed.
                     * @param _roundId the round ID to retrieve the round data for
                     * @return roundId is the round ID for which data was retrieved
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                    */
                    function proposedGetRoundData(uint80 _roundId)
                      public
                      view
                      checkAccess()
                      hasProposal()
                      override
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      return super.proposedGetRoundData(_roundId);
                    }
                  
                    /**
                     * @notice Used if an aggregator contract has been proposed.
                     * @return roundId is the round ID for which data was retrieved
                     * @return answer is the answer for the given round
                     * @return startedAt is the timestamp when the round was started.
                     * (Only some AggregatorV3Interface implementations return meaningful values)
                     * @return updatedAt is the timestamp when the round last was updated (i.e.
                     * answer was last computed)
                     * @return answeredInRound is the round ID of the round in which the answer
                     * was computed.
                    */
                    function proposedLatestRoundData()
                      public
                      view
                      checkAccess()
                      hasProposal()
                      override
                      returns (
                        uint80 roundId,
                        int256 answer,
                        uint256 startedAt,
                        uint256 updatedAt,
                        uint80 answeredInRound
                      )
                    {
                      return super.proposedLatestRoundData();
                    }
                  
                    /**
                     * @dev reverts if the caller does not have access by the accessController
                     * contract or is the contract itself.
                     */
                    modifier checkAccess() {
                      AccessControllerInterface ac = accessController;
                      require(address(ac) == address(0) || ac.hasAccess(msg.sender, msg.data), "No access");
                      _;
                    }
                  }

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

                  File 7 of 7: ERC20FeeProxy
                  pragma solidity ^0.5.0;
                  
                  
                  /**
                   * @title ERC20FeeProxy
                   * @notice This contract performs an ERC20 token transfer, with a Fee sent to a third address and stores a reference
                   */
                  contract ERC20FeeProxy {
                    // Event to declare a transfer with a reference
                    event TransferWithReferenceAndFee(
                      address tokenAddress,
                      address to,
                      uint256 amount,
                      bytes indexed paymentReference,
                      uint256 feeAmount,
                      address feeAddress
                    );
                  
                    // Fallback function returns funds to the sender
                    function() external payable {
                      revert("not payable fallback");
                    }
                  
                    /**
                      * @notice Performs a ERC20 token transfer with a reference and a transfer to a second address for the payment of a fee
                      * @param _tokenAddress Address of the ERC20 token smart contract
                      * @param _to Transfer recipient
                      * @param _amount Amount to transfer
                      * @param _paymentReference Reference of the payment related
                      * @param _feeAmount The amount of the payment fee
                      * @param _feeAddress The fee recipient
                      */
                    function transferFromWithReferenceAndFee(
                      address _tokenAddress,
                      address _to,
                      uint256 _amount,
                      bytes calldata _paymentReference,
                      uint256 _feeAmount,
                      address _feeAddress
                      ) external
                      {
                      require(safeTransferFrom(_tokenAddress, _to, _amount), "payment transferFrom() failed");
                      if (_feeAmount > 0 && _feeAddress != address(0)) {
                        require(safeTransferFrom(_tokenAddress, _feeAddress, _feeAmount), "fee transferFrom() failed");
                      }
                      emit TransferWithReferenceAndFee(
                        _tokenAddress,
                        _to,
                        _amount,
                        _paymentReference,
                        _feeAmount,
                        _feeAddress
                      );
                    }
                  
                    /**
                     * @notice Call transferFrom ERC20 function and validates the return data of a ERC20 contract call.
                     * @dev This is necessary because of non-standard ERC20 tokens that don't have a return value.
                     * @return The return value of the ERC20 call, returning true for non-standard tokens
                     */
                    function safeTransferFrom(address _tokenAddress, address _to, uint256 _amount) internal returns (bool result) {
                      /* solium-disable security/no-inline-assembly */
                      // check if the address is a contract
                      assembly {
                        if iszero(extcodesize(_tokenAddress)) { revert(0, 0) }
                      }
                      
                      // solium-disable-next-line security/no-low-level-calls
                      (bool success, ) = _tokenAddress.call(abi.encodeWithSignature(
                        "transferFrom(address,address,uint256)",
                        msg.sender,
                        _to,
                        _amount
                      ));
                  
                      assembly {
                          switch returndatasize()
                          case 0 { // not a standard erc20
                              result := 1
                          }
                          case 32 { // standard erc20
                              returndatacopy(0, 0, 32)
                              result := mload(0)
                          }
                          default { // anything else, should revert for safety
                              revert(0, 0)
                          }
                      }
                  
                      require(success, "transferFrom() has been reverted");
                  
                      /* solium-enable security/no-inline-assembly */
                      return result;
                    }
                  }