ETH Price: $2,414.68 (-1.01%)

Transaction Decoder

Block:
15379808 at Aug-20-2022 08:49:47 PM +UTC
Transaction Fee:
0.002897019839953218 ETH $7.00
Gas Used:
215,222 Gas / 13.460612019 Gwei

Emitted Events:

243 WeAllSurvivedDeath.Approval( owner=0xb2050c4fc92170e1196d5437ca01f0774843034b, approved=0x00000000...000000000, tokenId=7201 )
244 WeAllSurvivedDeath.Transfer( from=0xb2050c4fc92170e1196d5437ca01f0774843034b, to=[Sender] 0x2105d66926a88e240e132d5452de6a9518e742db, tokenId=7201 )
245 TransparentUpgradeableProxy.0xe2c49856b032c255ae7e325d18109bc4e22a2804e2e49a017ec0f59f19cd447b( 0xe2c49856b032c255ae7e325d18109bc4e22a2804e2e49a017ec0f59f19cd447b, 4c1f0a847c05524d5282ad48733489e9893b27a83220060cfdd0f35e6bde8c24, 0000000000000000000000000000000000000000000000000000000000000000, 000000000000000000000000b2050c4fc92170e1196d5437ca01f0774843034b, 000000000000000000000000000000000000000000000000004dc4d6ca222000 )
246 TransparentUpgradeableProxy.0x3cbb63f144840e5b1b0a38a7c19211d2e89de4d7c5faf8b2d3c1776c302d1d33( 0x3cbb63f144840e5b1b0a38a7c19211d2e89de4d7c5faf8b2d3c1776c302d1d33, 0x4c1f0a847c05524d5282ad48733489e9893b27a83220060cfdd0f35e6bde8c24, 000000000000000000000000b2050c4fc92170e1196d5437ca01f0774843034b, 0000000000000000000000002105d66926a88e240e132d5452de6a9518e742db, 00000000000000000000000000000000ca9196cb7c887735a2b7b2c2627863a7, 000000000000000000000000000000000000000000000000000012bd3183f790, 0000000000000000000000000000000000000000000000000000000000000001, 0000000000000000000000000000000000000000000000000000000000000001, 000000000000000000000000000000000000000000000000000000006328d5a0, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000160, 0000000000000000000000000000000000000000000000000000000000000180, 0000000000000000000000000000000000000000000000000000000000000260, 0000000000000000000000000000000000000000000000000000000000000000, 000000000000000000000000000000000000000000000000004e28e2290f0000, 0000000000000000000000000000000000000000000000000000000000000040, 0000000000000000000000000000000000000000000000000000000000000080, 0000000000000000000000000000000000000000000000000000000000000020, 0000000000000000000000000000000000000000000000000000000000000001, 00000000000000000000000027013d274aa60c6e6883aa2130e8b01249eb11d4, 0000000000000000000000000000000000000000000000000000000000001c21, 0000000000000000000000000000000000000000000000000000000000000001, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000, 000000000000000000000000000000000000000000000000004e28e2290f0000, 4c1f0a847c05524d5282ad48733489e9893b27a83220060cfdd0f35e6bde8c24, 000000000000000000000000f849de01b080adc3a814fabe1e2087475cf2e354, 0000000000000000000000000000000000000000000000000000000000000160, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000180, 0000000000000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000001, 0000000000000000000000000000000000000000000000000000000000001388, 000000000000000000000000d823c605807cc5e6bd6fc0d7e4eea50d3e2d66cd )

Account State Difference:

  Address   Before After State Difference Code
0x2105d669...518e742Db
0.050872996771443682 Eth
Nonce: 1220
0.025975976931490464 Eth
Nonce: 1221
0.024897019839953218
0x27013D27...249EB11d4
0x74312363...65a67EeD3
(X2Y2: Exchange)
(F2Pool Old)
4,150.146670675073831473 Eth4,150.147208730073831473 Eth0.000538055
0xB2050c4f...74843034B 0.488729493219312116 Eth0.510619493219312116 Eth0.02189
0xD823C605...d3e2d66cd
(X2Y2: Fee Management)
27.979138659260255386 Eth27.979248659260255386 Eth0.00011

Execution Trace

ETH 0.022 TransparentUpgradeableProxy.357a150b( )
  • ETH 0.022 X2Y2_r1.run( input=[{name:orders, type:tuple[], order:1, indexed:false}, {name:details, type:tuple[], order:2, indexed:false}, {name:shared, type:tuple, order:3, indexed:false, value:[{name:salt, type:uint256, order:1, indexed:false, value:20603788851088, valueString:20603788851088}, {name:deadline, type:uint256, order:2, indexed:false, value:1661039384, valueString:1661039384}, {name:amountToEth, type:uint256, order:3, indexed:false, value:0, valueString:0}, {name:amountToWeth, type:uint256, order:4, indexed:false, value:0, valueString:0}, {name:user, type:address, order:5, indexed:false, value:0x2105d66926a88E240e132d5452dE6A9518e742Db, valueString:0x2105d66926a88E240e132d5452dE6A9518e742Db}, {name:canFail, type:bool, order:6, indexed:false, value:false, valueString:False}], valueString:[{name:salt, type:uint256, order:1, indexed:false, value:20603788851088, valueString:20603788851088}, {name:deadline, type:uint256, order:2, indexed:false, value:1661039384, valueString:1661039384}, {name:amountToEth, type:uint256, order:3, indexed:false, value:0, valueString:0}, {name:amountToWeth, type:uint256, order:4, indexed:false, value:0, valueString:0}, {name:user, type:address, order:5, indexed:false, value:0x2105d66926a88E240e132d5452dE6A9518e742Db, valueString:0x2105d66926a88E240e132d5452dE6A9518e742Db}, {name:canFail, type:bool, order:6, indexed:false, value:false, valueString:False}]}, {name:r, type:bytes32, order:4, indexed:false, value:E7F4156ECA36CEEAB4E15F2228E978B45E2DDC9F62F226B3C4F0B8C062C9DAE5, valueString:E7F4156ECA36CEEAB4E15F2228E978B45E2DDC9F62F226B3C4F0B8C062C9DAE5}, {name:s, type:bytes32, order:5, indexed:false, value:20D54D88C131A8C40D8B024F7A30422545E6F58FC6CA12B5BDC3C316C5C6E588, valueString:20D54D88C131A8C40D8B024F7A30422545E6F58FC6CA12B5BDC3C316C5C6E588}, {name:v, type:uint8, order:6, indexed:false, value:28, valueString:28}] )
    • Null: 0x000...001.d6a80873( )
    • Null: 0x000...001.1c4184ee( )
    • ERC721Delegate.STATICCALL( )
    • ERC721Delegate.executeSell( seller=0xB2050c4fc92170e1196D5437cA01F0774843034B, buyer=0x2105d66926a88E240e132d5452dE6A9518e742Db, data=0x0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000100000000000000000000000027013D274AA60C6E6883AA2130E8B01249EB11D40000000000000000000000000000000000000000000000000000000000001C21 ) => ( True )
      • WeAllSurvivedDeath.safeTransferFrom( from=0xB2050c4fc92170e1196D5437cA01F0774843034B, to=0x2105d66926a88E240e132d5452dE6A9518e742Db, tokenId=7201 )
        • WyvernProxyRegistry.proxies( 0xB2050c4fc92170e1196D5437cA01F0774843034B ) => ( 0x0000000000000000000000000000000000000000 )
        • ETH 0.00011 FeeManagement.CALL( )
        • ETH 0.02189 0xb2050c4fc92170e1196d5437ca01f0774843034b.CALL( )
          File 1 of 6: TransparentUpgradeableProxy
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
          import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
          import "@openzeppelin/contracts/proxy/transparent/ProxyAdmin.sol";
          // Kept for backwards compatibility with older versions of Hardhat and Truffle plugins.
          contract AdminUpgradeabilityProxy is TransparentUpgradeableProxy {
              constructor(address logic, address admin, bytes memory data) payable TransparentUpgradeableProxy(logic, admin, data) {}
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../Proxy.sol";
          import "./ERC1967Upgrade.sol";
          /**
           * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
           * implementation address that can be changed. This address is stored in storage in the location specified by
           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
           * implementation behind the proxy.
           */
          contract ERC1967Proxy is Proxy, ERC1967Upgrade {
              /**
               * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
               *
               * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
               * function call, and allows initializating the storage of the proxy like a Solidity constructor.
               */
              constructor(address _logic, bytes memory _data) payable {
                  assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                  _upgradeToAndCall(_logic, _data, false);
              }
              /**
               * @dev Returns the current implementation address.
               */
              function _implementation() internal view virtual override returns (address impl) {
                  return ERC1967Upgrade._getImplementation();
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../ERC1967/ERC1967Proxy.sol";
          /**
           * @dev This contract implements a proxy that is upgradeable by an admin.
           *
           * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
           * clashing], which can potentially be used in an attack, this contract uses the
           * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
           * things that go hand in hand:
           *
           * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
           * that call matches one of the admin functions exposed by the proxy itself.
           * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
           * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
           * "admin cannot fallback to proxy target".
           *
           * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
           * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
           * to sudden errors when trying to call a function from the proxy implementation.
           *
           * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
           * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
           */
          contract TransparentUpgradeableProxy is ERC1967Proxy {
              /**
               * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
               * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
               */
              constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
                  assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                  _changeAdmin(admin_);
              }
              /**
               * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
               */
              modifier ifAdmin() {
                  if (msg.sender == _getAdmin()) {
                      _;
                  } else {
                      _fallback();
                  }
              }
              /**
               * @dev Returns the current admin.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
               *
               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
               * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
               */
              function admin() external ifAdmin returns (address admin_) {
                  admin_ = _getAdmin();
              }
              /**
               * @dev Returns the current implementation.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
               *
               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
               * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
               */
              function implementation() external ifAdmin returns (address implementation_) {
                  implementation_ = _implementation();
              }
              /**
               * @dev Changes the admin of the proxy.
               *
               * Emits an {AdminChanged} event.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
               */
              function changeAdmin(address newAdmin) external virtual ifAdmin {
                  _changeAdmin(newAdmin);
              }
              /**
               * @dev Upgrade the implementation of the proxy.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
               */
              function upgradeTo(address newImplementation) external ifAdmin {
                  _upgradeToAndCall(newImplementation, bytes(""), false);
              }
              /**
               * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
               * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
               * proxied contract.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
               */
              function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                  _upgradeToAndCall(newImplementation, data, true);
              }
              /**
               * @dev Returns the current admin.
               */
              function _admin() internal view virtual returns (address) {
                  return _getAdmin();
              }
              /**
               * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
               */
              function _beforeFallback() internal virtual override {
                  require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                  super._beforeFallback();
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "./TransparentUpgradeableProxy.sol";
          import "../../access/Ownable.sol";
          /**
           * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
           * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
           */
          contract ProxyAdmin is Ownable {
              /**
               * @dev Returns the current implementation of `proxy`.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
                  // We need to manually run the static call since the getter cannot be flagged as view
                  // bytes4(keccak256("implementation()")) == 0x5c60da1b
                  (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
                  require(success);
                  return abi.decode(returndata, (address));
              }
              /**
               * @dev Returns the current admin of `proxy`.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
                  // We need to manually run the static call since the getter cannot be flagged as view
                  // bytes4(keccak256("admin()")) == 0xf851a440
                  (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
                  require(success);
                  return abi.decode(returndata, (address));
              }
              /**
               * @dev Changes the admin of `proxy` to `newAdmin`.
               *
               * Requirements:
               *
               * - This contract must be the current admin of `proxy`.
               */
              function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
                  proxy.changeAdmin(newAdmin);
              }
              /**
               * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
                  proxy.upgradeTo(implementation);
              }
              /**
               * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
               * {TransparentUpgradeableProxy-upgradeToAndCall}.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
                  proxy.upgradeToAndCall{value: msg.value}(implementation, data);
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
           * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
           * be specified by overriding the virtual {_implementation} function.
           *
           * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
           * different contract through the {_delegate} function.
           *
           * The success and return data of the delegated call will be returned back to the caller of the proxy.
           */
          abstract contract Proxy {
              /**
               * @dev Delegates the current call to `implementation`.
               *
               * This function does not return to its internall call site, it will return directly to the external caller.
               */
              function _delegate(address implementation) internal virtual {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // Copy msg.data. We take full control of memory in this inline assembly
                      // block because it will not return to Solidity code. We overwrite the
                      // Solidity scratch pad at memory position 0.
                      calldatacopy(0, 0, calldatasize())
                      // Call the implementation.
                      // out and outsize are 0 because we don't know the size yet.
                      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                      // Copy the returned data.
                      returndatacopy(0, 0, returndatasize())
                      switch result
                      // delegatecall returns 0 on error.
                      case 0 { revert(0, returndatasize()) }
                      default { return(0, returndatasize()) }
                  }
              }
              /**
               * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
               * and {_fallback} should delegate.
               */
              function _implementation() internal view virtual returns (address);
              /**
               * @dev Delegates the current call to the address returned by `_implementation()`.
               *
               * This function does not return to its internall call site, it will return directly to the external caller.
               */
              function _fallback() internal virtual {
                  _beforeFallback();
                  _delegate(_implementation());
              }
              /**
               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
               * function in the contract matches the call data.
               */
              fallback () external payable virtual {
                  _fallback();
              }
              /**
               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
               * is empty.
               */
              receive () external payable virtual {
                  _fallback();
              }
              /**
               * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
               * call, or as part of the Solidity `fallback` or `receive` functions.
               *
               * If overriden should call `super._beforeFallback()`.
               */
              function _beforeFallback() internal virtual {
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.2;
          import "../beacon/IBeacon.sol";
          import "../../utils/Address.sol";
          import "../../utils/StorageSlot.sol";
          /**
           * @dev This abstract contract provides getters and event emitting update functions for
           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
           *
           * _Available since v4.1._
           *
           * @custom:oz-upgrades-unsafe-allow delegatecall
           */
          abstract contract ERC1967Upgrade {
              // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
              bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
              /**
               * @dev Storage slot with the address of the current implementation.
               * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
               * validated in the constructor.
               */
              bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
              /**
               * @dev Emitted when the implementation is upgraded.
               */
              event Upgraded(address indexed implementation);
              /**
               * @dev Returns the current implementation address.
               */
              function _getImplementation() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
              }
              /**
               * @dev Stores a new address in the EIP1967 implementation slot.
               */
              function _setImplementation(address newImplementation) private {
                  require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                  StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
              }
              /**
               * @dev Perform implementation upgrade
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeTo(address newImplementation) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
              }
              /**
               * @dev Perform implementation upgrade with additional setup call.
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(newImplementation, data);
                  }
              }
              /**
               * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
                  address oldImplementation = _getImplementation();
                  // Initial upgrade and setup call
                  _setImplementation(newImplementation);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(newImplementation, data);
                  }
                  // Perform rollback test if not already in progress
                  StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                  if (!rollbackTesting.value) {
                      // Trigger rollback using upgradeTo from the new implementation
                      rollbackTesting.value = true;
                      Address.functionDelegateCall(
                          newImplementation,
                          abi.encodeWithSignature(
                              "upgradeTo(address)",
                              oldImplementation
                          )
                      );
                      rollbackTesting.value = false;
                      // Check rollback was effective
                      require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                      // Finally reset to the new implementation and log the upgrade
                      _setImplementation(newImplementation);
                      emit Upgraded(newImplementation);
                  }
              }
              /**
               * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
               * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
               *
               * Emits a {BeaconUpgraded} event.
               */
              function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
                  _setBeacon(newBeacon);
                  emit BeaconUpgraded(newBeacon);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                  }
              }
              /**
               * @dev Storage slot with the admin of the contract.
               * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
               * validated in the constructor.
               */
              bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
              /**
               * @dev Emitted when the admin account has changed.
               */
              event AdminChanged(address previousAdmin, address newAdmin);
              /**
               * @dev Returns the current admin.
               */
              function _getAdmin() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
              }
              /**
               * @dev Stores a new address in the EIP1967 admin slot.
               */
              function _setAdmin(address newAdmin) private {
                  require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                  StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
              }
              /**
               * @dev Changes the admin of the proxy.
               *
               * Emits an {AdminChanged} event.
               */
              function _changeAdmin(address newAdmin) internal {
                  emit AdminChanged(_getAdmin(), newAdmin);
                  _setAdmin(newAdmin);
              }
              /**
               * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
               * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
               */
              bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
              /**
               * @dev Emitted when the beacon is upgraded.
               */
              event BeaconUpgraded(address indexed beacon);
              /**
               * @dev Returns the current beacon.
               */
              function _getBeacon() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
              }
              /**
               * @dev Stores a new beacon in the EIP1967 beacon slot.
               */
              function _setBeacon(address newBeacon) private {
                  require(
                      Address.isContract(newBeacon),
                      "ERC1967: new beacon is not a contract"
                  );
                  require(
                      Address.isContract(IBeacon(newBeacon).implementation()),
                      "ERC1967: beacon implementation is not a contract"
                  );
                  StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This is the interface that {BeaconProxy} expects of its beacon.
           */
          interface IBeacon {
              /**
               * @dev Must return an address that can be used as a delegate call target.
               *
               * {BeaconProxy} will check that this address is a contract.
               */
              function implementation() external view returns (address);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^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 ^0.8.0;
          /**
           * @dev Library for reading and writing primitive types to specific storage slots.
           *
           * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
           * This library helps with reading and writing to such slots without the need for inline assembly.
           *
           * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
           *
           * Example usage to set ERC1967 implementation slot:
           * ```
           * contract ERC1967 {
           *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
           *
           *     function _getImplementation() internal view returns (address) {
           *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
           *     }
           *
           *     function _setImplementation(address newImplementation) internal {
           *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
           *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
           *     }
           * }
           * ```
           *
           * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
           */
          library StorageSlot {
              struct AddressSlot {
                  address value;
              }
              struct BooleanSlot {
                  bool value;
              }
              struct Bytes32Slot {
                  bytes32 value;
              }
              struct Uint256Slot {
                  uint256 value;
              }
              /**
               * @dev Returns an `AddressSlot` with member `value` located at `slot`.
               */
              function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
               */
              function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
               */
              function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
               */
              function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/Context.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable is Context {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              constructor () {
                  address msgSender = _msgSender();
                  _owner = msgSender;
                  emit OwnershipTransferred(address(0), msgSender);
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  emit OwnershipTransferred(_owner, address(0));
                  _owner = address(0);
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  emit OwnershipTransferred(_owner, newOwner);
                  _owner = newOwner;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /*
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract Context {
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                  return msg.data;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../ERC1967/ERC1967Upgrade.sol";
          /**
           * @dev Base contract for building openzeppelin-upgrades compatible implementations for the {ERC1967Proxy}. It includes
           * publicly available upgrade functions that are called by the plugin and by the secure upgrade mechanism to verify
           * continuation of the upgradability.
           *
           * The {_authorizeUpgrade} function MUST be overridden to include access restriction to the upgrade mechanism.
           *
           * _Available since v4.1._
           */
          abstract contract UUPSUpgradeable is ERC1967Upgrade {
              function upgradeTo(address newImplementation) external virtual {
                  _authorizeUpgrade(newImplementation);
                  _upgradeToAndCallSecure(newImplementation, bytes(""), false);
              }
              function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual {
                  _authorizeUpgrade(newImplementation);
                  _upgradeToAndCallSecure(newImplementation, data, true);
              }
              function _authorizeUpgrade(address newImplementation) internal virtual;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.2;
          import "@openzeppelin/contracts/proxy/utils/UUPSUpgradeable.sol";
          abstract contract Proxiable is UUPSUpgradeable {
              function _authorizeUpgrade(address newImplementation) internal override {
                  _beforeUpgrade(newImplementation);
              }
              function _beforeUpgrade(address newImplementation) internal virtual;
          }
          contract ChildOfProxiable is Proxiable {
              function _beforeUpgrade(address newImplementation) internal virtual override {}
          }
          

          File 2 of 6: WeAllSurvivedDeath
          /* SPDX-License-Identifier: MIT */
          
          // Sources flattened with hardhat v2.9.1 https://hardhat.org
          
          // File @openzeppelin/contracts/utils/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract Context {
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
          
              function _msgData() internal view virtual returns (bytes calldata) {
                  return msg.data;
              }
          }
          
          
          // File @openzeppelin/contracts/access/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable is Context {
              address private _owner;
          
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              constructor() {
                  _transferOwnership(_msgSender());
              }
          
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
          
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
          
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  _transferOwnership(address(0));
              }
          
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  _transferOwnership(newOwner);
              }
          
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Internal function without access restriction.
               */
              function _transferOwnership(address newOwner) internal virtual {
                  address oldOwner = _owner;
                  _owner = newOwner;
                  emit OwnershipTransferred(oldOwner, newOwner);
              }
          }
          
          
          // File @openzeppelin/contracts/security/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Contract module which allows children to implement an emergency stop
           * mechanism that can be triggered by an authorized account.
           *
           * This module is used through inheritance. It will make available the
           * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
           * the functions of your contract. Note that they will not be pausable by
           * simply including this module, only once the modifiers are put in place.
           */
          abstract contract Pausable is Context {
              /**
               * @dev Emitted when the pause is triggered by `account`.
               */
              event Paused(address account);
          
              /**
               * @dev Emitted when the pause is lifted by `account`.
               */
              event Unpaused(address account);
          
              bool private _paused;
          
              /**
               * @dev Initializes the contract in unpaused state.
               */
              constructor() {
                  _paused = false;
              }
          
              /**
               * @dev Returns true if the contract is paused, and false otherwise.
               */
              function paused() public view virtual returns (bool) {
                  return _paused;
              }
          
              /**
               * @dev Modifier to make a function callable only when the contract is not paused.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              modifier whenNotPaused() {
                  require(!paused(), "Pausable: paused");
                  _;
              }
          
              /**
               * @dev Modifier to make a function callable only when the contract is paused.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              modifier whenPaused() {
                  require(paused(), "Pausable: not paused");
                  _;
              }
          
              /**
               * @dev Triggers stopped state.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              function _pause() internal virtual whenNotPaused {
                  _paused = true;
                  emit Paused(_msgSender());
              }
          
              /**
               * @dev Returns to normal state.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              function _unpause() internal virtual whenPaused {
                  _paused = false;
                  emit Unpaused(_msgSender());
              }
          }
          
          
          // File @openzeppelin/contracts/utils/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev String operations.
           */
          library Strings {
              bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
          
              /**
               * @dev Converts a `uint256` to its ASCII `string` decimal representation.
               */
              function toString(uint256 value) internal pure returns (string memory) {
                  // Inspired by OraclizeAPI's implementation - MIT licence
                  // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
          
                  if (value == 0) {
                      return "0";
                  }
                  uint256 temp = value;
                  uint256 digits;
                  while (temp != 0) {
                      digits++;
                      temp /= 10;
                  }
                  bytes memory buffer = new bytes(digits);
                  while (value != 0) {
                      digits -= 1;
                      buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                      value /= 10;
                  }
                  return string(buffer);
              }
          
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
               */
              function toHexString(uint256 value) internal pure returns (string memory) {
                  if (value == 0) {
                      return "0x00";
                  }
                  uint256 temp = value;
                  uint256 length = 0;
                  while (temp != 0) {
                      length++;
                      temp >>= 8;
                  }
                  return toHexString(value, length);
              }
          
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
               */
              function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                  bytes memory buffer = new bytes(2 * length + 2);
                  buffer[0] = "0";
                  buffer[1] = "x";
                  for (uint256 i = 2 * length + 1; i > 1; --i) {
                      buffer[i] = _HEX_SYMBOLS[value & 0xf];
                      value >>= 4;
                  }
                  require(value == 0, "Strings: hex length insufficient");
                  return string(buffer);
              }
          }
          
          
          // File @openzeppelin/contracts/utils/cryptography/[email protected]
          
          // OpenZeppelin Contracts (last updated v4.5.0) (utils/cryptography/ECDSA.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
           *
           * These functions can be used to verify that a message was signed by the holder
           * of the private keys of a given address.
           */
          library ECDSA {
              enum RecoverError {
                  NoError,
                  InvalidSignature,
                  InvalidSignatureLength,
                  InvalidSignatureS,
                  InvalidSignatureV
              }
          
              function _throwError(RecoverError error) private pure {
                  if (error == RecoverError.NoError) {
                      return; // no error: do nothing
                  } else if (error == RecoverError.InvalidSignature) {
                      revert("ECDSA: invalid signature");
                  } else if (error == RecoverError.InvalidSignatureLength) {
                      revert("ECDSA: invalid signature length");
                  } else if (error == RecoverError.InvalidSignatureS) {
                      revert("ECDSA: invalid signature 's' value");
                  } else if (error == RecoverError.InvalidSignatureV) {
                      revert("ECDSA: invalid signature 'v' value");
                  }
              }
          
              /**
               * @dev Returns the address that signed a hashed message (`hash`) with
               * `signature` or error string. This address can then be used for verification purposes.
               *
               * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
               * this function rejects them by requiring the `s` value to be in the lower
               * half order, and the `v` value to be either 27 or 28.
               *
               * IMPORTANT: `hash` _must_ be the result of a hash operation for the
               * verification to be secure: it is possible to craft signatures that
               * recover to arbitrary addresses for non-hashed data. A safe way to ensure
               * this is by receiving a hash of the original message (which may otherwise
               * be too long), and then calling {toEthSignedMessageHash} on it.
               *
               * Documentation for signature generation:
               * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
               * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
               *
               * _Available since v4.3._
               */
              function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
                  // Check the signature length
                  // - case 65: r,s,v signature (standard)
                  // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
                  if (signature.length == 65) {
                      bytes32 r;
                      bytes32 s;
                      uint8 v;
                      // ecrecover takes the signature parameters, and the only way to get them
                      // currently is to use assembly.
                      assembly {
                          r := mload(add(signature, 0x20))
                          s := mload(add(signature, 0x40))
                          v := byte(0, mload(add(signature, 0x60)))
                      }
                      return tryRecover(hash, v, r, s);
                  } else if (signature.length == 64) {
                      bytes32 r;
                      bytes32 vs;
                      // ecrecover takes the signature parameters, and the only way to get them
                      // currently is to use assembly.
                      assembly {
                          r := mload(add(signature, 0x20))
                          vs := mload(add(signature, 0x40))
                      }
                      return tryRecover(hash, r, vs);
                  } else {
                      return (address(0), RecoverError.InvalidSignatureLength);
                  }
              }
          
              /**
               * @dev Returns the address that signed a hashed message (`hash`) with
               * `signature`. This address can then be used for verification purposes.
               *
               * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
               * this function rejects them by requiring the `s` value to be in the lower
               * half order, and the `v` value to be either 27 or 28.
               *
               * IMPORTANT: `hash` _must_ be the result of a hash operation for the
               * verification to be secure: it is possible to craft signatures that
               * recover to arbitrary addresses for non-hashed data. A safe way to ensure
               * this is by receiving a hash of the original message (which may otherwise
               * be too long), and then calling {toEthSignedMessageHash} on it.
               */
              function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
                  (address recovered, RecoverError error) = tryRecover(hash, signature);
                  _throwError(error);
                  return recovered;
              }
          
              /**
               * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
               *
               * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
               *
               * _Available since v4.3._
               */
              function tryRecover(
                  bytes32 hash,
                  bytes32 r,
                  bytes32 vs
              ) internal pure returns (address, RecoverError) {
                  bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
                  uint8 v = uint8((uint256(vs) >> 255) + 27);
                  return tryRecover(hash, v, r, s);
              }
          
              /**
               * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
               *
               * _Available since v4.2._
               */
              function recover(
                  bytes32 hash,
                  bytes32 r,
                  bytes32 vs
              ) internal pure returns (address) {
                  (address recovered, RecoverError error) = tryRecover(hash, r, vs);
                  _throwError(error);
                  return recovered;
              }
          
              /**
               * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
               * `r` and `s` signature fields separately.
               *
               * _Available since v4.3._
               */
              function tryRecover(
                  bytes32 hash,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) internal pure returns (address, RecoverError) {
                  // 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 (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): 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) {
                      return (address(0), RecoverError.InvalidSignatureS);
                  }
                  if (v != 27 && v != 28) {
                      return (address(0), RecoverError.InvalidSignatureV);
                  }
          
                  // If the signature is valid (and not malleable), return the signer address
                  address signer = ecrecover(hash, v, r, s);
                  if (signer == address(0)) {
                      return (address(0), RecoverError.InvalidSignature);
                  }
          
                  return (signer, RecoverError.NoError);
              }
          
              /**
               * @dev Overload of {ECDSA-recover} that receives the `v`,
               * `r` and `s` signature fields separately.
               */
              function recover(
                  bytes32 hash,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) internal pure returns (address) {
                  (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
                  _throwError(error);
                  return recovered;
              }
          
              /**
               * @dev Returns an Ethereum Signed Message, created from a `hash`. This
               * produces hash corresponding to the one signed with the
               * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
               * JSON-RPC method as part of EIP-191.
               *
               * See {recover}.
               */
              function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
                  // 32 is the length in bytes of hash,
                  // enforced by the type signature above
                  return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
              }
          
              /**
               * @dev Returns an Ethereum Signed Message, created from `s`. This
               * produces hash corresponding to the one signed with the
               * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
               * JSON-RPC method as part of EIP-191.
               *
               * See {recover}.
               */
              function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
                  return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
              }
          
              /**
               * @dev Returns an Ethereum Signed Typed Data, created from a
               * `domainSeparator` and a `structHash`. This produces hash corresponding
               * to the one signed with the
               * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
               * JSON-RPC method as part of EIP-712.
               *
               * See {recover}.
               */
              function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
                  return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
              }
          }
          
          
          // File @openzeppelin/contracts/utils/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @title Counters
           * @author Matt Condon (@shrugs)
           * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
           * of elements in a mapping, issuing ERC721 ids, or counting request ids.
           *
           * Include with `using Counters for Counters.Counter;`
           */
          library Counters {
              struct Counter {
                  // This variable should never be directly accessed by users of the library: interactions must be restricted to
                  // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
                  // this feature: see https://github.com/ethereum/solidity/issues/4637
                  uint256 _value; // default: 0
              }
          
              function current(Counter storage counter) internal view returns (uint256) {
                  return counter._value;
              }
          
              function increment(Counter storage counter) internal {
                  unchecked {
                      counter._value += 1;
                  }
              }
          
              function decrement(Counter storage counter) internal {
                  uint256 value = counter._value;
                  require(value > 0, "Counter: decrement overflow");
                  unchecked {
                      counter._value = value - 1;
                  }
              }
          
              function reset(Counter storage counter) internal {
                  counter._value = 0;
              }
          }
          
          
          // File @openzeppelin/contracts/access/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev External interface of AccessControl declared to support ERC165 detection.
           */
          interface IAccessControl {
              /**
               * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
               *
               * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
               * {RoleAdminChanged} not being emitted signaling this.
               *
               * _Available since v3.1._
               */
              event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
          
              /**
               * @dev Emitted when `account` is granted `role`.
               *
               * `sender` is the account that originated the contract call, an admin role
               * bearer except when using {AccessControl-_setupRole}.
               */
              event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
          
              /**
               * @dev Emitted when `account` is revoked `role`.
               *
               * `sender` is the account that originated the contract call:
               *   - if using `revokeRole`, it is the admin role bearer
               *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
               */
              event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
          
              /**
               * @dev Returns `true` if `account` has been granted `role`.
               */
              function hasRole(bytes32 role, address account) external view returns (bool);
          
              /**
               * @dev Returns the admin role that controls `role`. See {grantRole} and
               * {revokeRole}.
               *
               * To change a role's admin, use {AccessControl-_setRoleAdmin}.
               */
              function getRoleAdmin(bytes32 role) external view returns (bytes32);
          
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function grantRole(bytes32 role, address account) external;
          
              /**
               * @dev Revokes `role` from `account`.
               *
               * If `account` had been granted `role`, emits a {RoleRevoked} event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function revokeRole(bytes32 role, address account) external;
          
              /**
               * @dev Revokes `role` from the calling account.
               *
               * Roles are often managed via {grantRole} and {revokeRole}: this function's
               * purpose is to provide a mechanism for accounts to lose their privileges
               * if they are compromised (such as when a trusted device is misplaced).
               *
               * If the calling account had been granted `role`, emits a {RoleRevoked}
               * event.
               *
               * Requirements:
               *
               * - the caller must be `account`.
               */
              function renounceRole(bytes32 role, address account) external;
          }
          
          
          // File @openzeppelin/contracts/utils/introspection/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Interface of the ERC165 standard, as defined in the
           * https://eips.ethereum.org/EIPS/eip-165[EIP].
           *
           * Implementers can declare support of contract interfaces, which can then be
           * queried by others ({ERC165Checker}).
           *
           * For an implementation, see {ERC165}.
           */
          interface IERC165 {
              /**
               * @dev Returns true if this contract implements the interface defined by
               * `interfaceId`. See the corresponding
               * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
               * to learn more about how these ids are created.
               *
               * This function call must use less than 30 000 gas.
               */
              function supportsInterface(bytes4 interfaceId) external view returns (bool);
          }
          
          
          // File @openzeppelin/contracts/utils/introspection/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Implementation of the {IERC165} interface.
           *
           * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
           * for the additional interface id that will be supported. For example:
           *
           * ```solidity
           * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
           *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
           * }
           * ```
           *
           * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
           */
          abstract contract ERC165 is IERC165 {
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                  return interfaceId == type(IERC165).interfaceId;
              }
          }
          
          
          // File @openzeppelin/contracts/access/[email protected]
          
          // OpenZeppelin Contracts (last updated v4.5.0) (access/AccessControl.sol)
          
          pragma solidity ^0.8.0;
          
          
          
          
          /**
           * @dev Contract module that allows children to implement role-based access
           * control mechanisms. This is a lightweight version that doesn't allow enumerating role
           * members except through off-chain means by accessing the contract event logs. Some
           * applications may benefit from on-chain enumerability, for those cases see
           * {AccessControlEnumerable}.
           *
           * Roles are referred to by their `bytes32` identifier. These should be exposed
           * in the external API and be unique. The best way to achieve this is by
           * using `public constant` hash digests:
           *
           * ```
           * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
           * ```
           *
           * Roles can be used to represent a set of permissions. To restrict access to a
           * function call, use {hasRole}:
           *
           * ```
           * function foo() public {
           *     require(hasRole(MY_ROLE, msg.sender));
           *     ...
           * }
           * ```
           *
           * Roles can be granted and revoked dynamically via the {grantRole} and
           * {revokeRole} functions. Each role has an associated admin role, and only
           * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
           *
           * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
           * that only accounts with this role will be able to grant or revoke other
           * roles. More complex role relationships can be created by using
           * {_setRoleAdmin}.
           *
           * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
           * grant and revoke this role. Extra precautions should be taken to secure
           * accounts that have been granted it.
           */
          abstract contract AccessControl is Context, IAccessControl, ERC165 {
              struct RoleData {
                  mapping(address => bool) members;
                  bytes32 adminRole;
              }
          
              mapping(bytes32 => RoleData) private _roles;
          
              bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
          
              /**
               * @dev Modifier that checks that an account has a specific role. Reverts
               * with a standardized message including the required role.
               *
               * The format of the revert reason is given by the following regular expression:
               *
               *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
               *
               * _Available since v4.1._
               */
              modifier onlyRole(bytes32 role) {
                  _checkRole(role, _msgSender());
                  _;
              }
          
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                  return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
              }
          
              /**
               * @dev Returns `true` if `account` has been granted `role`.
               */
              function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
                  return _roles[role].members[account];
              }
          
              /**
               * @dev Revert with a standard message if `account` is missing `role`.
               *
               * The format of the revert reason is given by the following regular expression:
               *
               *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
               */
              function _checkRole(bytes32 role, address account) internal view virtual {
                  if (!hasRole(role, account)) {
                      revert(
                          string(
                              abi.encodePacked(
                                  "AccessControl: account ",
                                  Strings.toHexString(uint160(account), 20),
                                  " is missing role ",
                                  Strings.toHexString(uint256(role), 32)
                              )
                          )
                      );
                  }
              }
          
              /**
               * @dev Returns the admin role that controls `role`. See {grantRole} and
               * {revokeRole}.
               *
               * To change a role's admin, use {_setRoleAdmin}.
               */
              function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
                  return _roles[role].adminRole;
              }
          
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                  _grantRole(role, account);
              }
          
              /**
               * @dev Revokes `role` from `account`.
               *
               * If `account` had been granted `role`, emits a {RoleRevoked} event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                  _revokeRole(role, account);
              }
          
              /**
               * @dev Revokes `role` from the calling account.
               *
               * Roles are often managed via {grantRole} and {revokeRole}: this function's
               * purpose is to provide a mechanism for accounts to lose their privileges
               * if they are compromised (such as when a trusted device is misplaced).
               *
               * If the calling account had been revoked `role`, emits a {RoleRevoked}
               * event.
               *
               * Requirements:
               *
               * - the caller must be `account`.
               */
              function renounceRole(bytes32 role, address account) public virtual override {
                  require(account == _msgSender(), "AccessControl: can only renounce roles for self");
          
                  _revokeRole(role, account);
              }
          
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event. Note that unlike {grantRole}, this function doesn't perform any
               * checks on the calling account.
               *
               * [WARNING]
               * ====
               * This function should only be called from the constructor when setting
               * up the initial roles for the system.
               *
               * Using this function in any other way is effectively circumventing the admin
               * system imposed by {AccessControl}.
               * ====
               *
               * NOTE: This function is deprecated in favor of {_grantRole}.
               */
              function _setupRole(bytes32 role, address account) internal virtual {
                  _grantRole(role, account);
              }
          
              /**
               * @dev Sets `adminRole` as ``role``'s admin role.
               *
               * Emits a {RoleAdminChanged} event.
               */
              function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                  bytes32 previousAdminRole = getRoleAdmin(role);
                  _roles[role].adminRole = adminRole;
                  emit RoleAdminChanged(role, previousAdminRole, adminRole);
              }
          
              /**
               * @dev Grants `role` to `account`.
               *
               * Internal function without access restriction.
               */
              function _grantRole(bytes32 role, address account) internal virtual {
                  if (!hasRole(role, account)) {
                      _roles[role].members[account] = true;
                      emit RoleGranted(role, account, _msgSender());
                  }
              }
          
              /**
               * @dev Revokes `role` from `account`.
               *
               * Internal function without access restriction.
               */
              function _revokeRole(bytes32 role, address account) internal virtual {
                  if (hasRole(role, account)) {
                      _roles[role].members[account] = false;
                      emit RoleRevoked(role, account, _msgSender());
                  }
              }
          }
          
          
          // File @openzeppelin/contracts/token/ERC721/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @dev Required interface of an ERC721 compliant contract.
           */
          interface IERC721 is IERC165 {
              /**
               * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
               */
              event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
          
              /**
               * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
               */
              event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
          
              /**
               * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
               */
              event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
          
              /**
               * @dev Returns the number of tokens in ``owner``'s account.
               */
              function balanceOf(address owner) external view returns (uint256 balance);
          
              /**
               * @dev Returns the owner of the `tokenId` token.
               *
               * Requirements:
               *
               * - `tokenId` must exist.
               */
              function ownerOf(uint256 tokenId) external view returns (address owner);
          
              /**
               * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
               * are aware of the ERC721 protocol to prevent tokens from being forever locked.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must exist and be owned by `from`.
               * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
               * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
               *
               * Emits a {Transfer} event.
               */
              function safeTransferFrom(
                  address from,
                  address to,
                  uint256 tokenId
              ) external;
          
              /**
               * @dev Transfers `tokenId` token from `from` to `to`.
               *
               * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must be owned by `from`.
               * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
               *
               * Emits a {Transfer} event.
               */
              function transferFrom(
                  address from,
                  address to,
                  uint256 tokenId
              ) external;
          
              /**
               * @dev Gives permission to `to` to transfer `tokenId` token to another account.
               * The approval is cleared when the token is transferred.
               *
               * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
               *
               * Requirements:
               *
               * - The caller must own the token or be an approved operator.
               * - `tokenId` must exist.
               *
               * Emits an {Approval} event.
               */
              function approve(address to, uint256 tokenId) external;
          
              /**
               * @dev Returns the account approved for `tokenId` token.
               *
               * Requirements:
               *
               * - `tokenId` must exist.
               */
              function getApproved(uint256 tokenId) external view returns (address operator);
          
              /**
               * @dev Approve or remove `operator` as an operator for the caller.
               * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
               *
               * Requirements:
               *
               * - The `operator` cannot be the caller.
               *
               * Emits an {ApprovalForAll} event.
               */
              function setApprovalForAll(address operator, bool _approved) external;
          
              /**
               * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
               *
               * See {setApprovalForAll}
               */
              function isApprovedForAll(address owner, address operator) external view returns (bool);
          
              /**
               * @dev Safely transfers `tokenId` token from `from` to `to`.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must exist and be owned by `from`.
               * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
               * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
               *
               * Emits a {Transfer} event.
               */
              function safeTransferFrom(
                  address from,
                  address to,
                  uint256 tokenId,
                  bytes calldata data
              ) external;
          }
          
          
          // File @openzeppelin/contracts/token/ERC721/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @title ERC721 token receiver interface
           * @dev Interface for any contract that wants to support safeTransfers
           * from ERC721 asset contracts.
           */
          interface IERC721Receiver {
              /**
               * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
               * by `operator` from `from`, this function is called.
               *
               * It must return its Solidity selector to confirm the token transfer.
               * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
               *
               * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
               */
              function onERC721Received(
                  address operator,
                  address from,
                  uint256 tokenId,
                  bytes calldata data
              ) external returns (bytes4);
          }
          
          
          // File @openzeppelin/contracts/token/ERC721/extensions/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
           * @dev See https://eips.ethereum.org/EIPS/eip-721
           */
          interface IERC721Metadata is IERC721 {
              /**
               * @dev Returns the token collection name.
               */
              function name() external view returns (string memory);
          
              /**
               * @dev Returns the token collection symbol.
               */
              function symbol() external view returns (string memory);
          
              /**
               * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
               */
              function tokenURI(uint256 tokenId) external view returns (string memory);
          }
          
          
          // File @openzeppelin/contracts/utils/[email protected]
          
          // OpenZeppelin Contracts (last updated v4.5.0) (utils/Address.sol)
          
          pragma solidity ^0.8.1;
          
          /**
           * @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
               * ====
               *
               * [IMPORTANT]
               * ====
               * You shouldn't rely on `isContract` to protect against flash loan attacks!
               *
               * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
               * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
               * constructor.
               * ====
               */
              function isContract(address account) internal view returns (bool) {
                  // This method relies on extcodesize/address.code.length, which returns 0
                  // for contracts in construction, since the code is only stored at the end
                  // of the constructor execution.
          
                  return account.code.length > 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");
          
                  (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");
          
                  (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");
          
                  (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");
          
                  (bool success, bytes memory returndata) = target.delegatecall(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
          
              /**
               * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
               * revert reason using the provided one.
               *
               * _Available since v4.3._
               */
              function verifyCallResult(
                  bool success,
                  bytes memory returndata,
                  string memory errorMessage
              ) internal 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
          
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }
          
          
          // File @openzeppelin/contracts/token/ERC721/[email protected]
          
          // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/ERC721.sol)
          
          pragma solidity ^0.8.0;
          
          
          
          
          
          
          
          /**
           * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
           * the Metadata extension, but not including the Enumerable extension, which is available separately as
           * {ERC721Enumerable}.
           */
          contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
              using Address for address;
              using Strings for uint256;
          
              // Token name
              string private _name;
          
              // Token symbol
              string private _symbol;
          
              // Mapping from token ID to owner address
              mapping(uint256 => address) private _owners;
          
              // Mapping owner address to token count
              mapping(address => uint256) private _balances;
          
              // Mapping from token ID to approved address
              mapping(uint256 => address) private _tokenApprovals;
          
              // Mapping from owner to operator approvals
              mapping(address => mapping(address => bool)) private _operatorApprovals;
          
              /**
               * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
               */
              constructor(string memory name_, string memory symbol_) {
                  _name = name_;
                  _symbol = symbol_;
              }
          
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
                  return
                      interfaceId == type(IERC721).interfaceId ||
                      interfaceId == type(IERC721Metadata).interfaceId ||
                      super.supportsInterface(interfaceId);
              }
          
              /**
               * @dev See {IERC721-balanceOf}.
               */
              function balanceOf(address owner) public view virtual override returns (uint256) {
                  require(owner != address(0), "ERC721: balance query for the zero address");
                  return _balances[owner];
              }
          
              /**
               * @dev See {IERC721-ownerOf}.
               */
              function ownerOf(uint256 tokenId) public view virtual override returns (address) {
                  address owner = _owners[tokenId];
                  require(owner != address(0), "ERC721: owner query for nonexistent token");
                  return owner;
              }
          
              /**
               * @dev See {IERC721Metadata-name}.
               */
              function name() public view virtual override returns (string memory) {
                  return _name;
              }
          
              /**
               * @dev See {IERC721Metadata-symbol}.
               */
              function symbol() public view virtual override returns (string memory) {
                  return _symbol;
              }
          
              /**
               * @dev See {IERC721Metadata-tokenURI}.
               */
              function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
                  require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
          
                  string memory baseURI = _baseURI();
                  return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
              }
          
              /**
               * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
               * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
               * by default, can be overriden in child contracts.
               */
              function _baseURI() internal view virtual returns (string memory) {
                  return "";
              }
          
              /**
               * @dev See {IERC721-approve}.
               */
              function approve(address to, uint256 tokenId) public virtual override {
                  address owner = ERC721.ownerOf(tokenId);
                  require(to != owner, "ERC721: approval to current owner");
          
                  require(
                      _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
                      "ERC721: approve caller is not owner nor approved for all"
                  );
          
                  _approve(to, tokenId);
              }
          
              /**
               * @dev See {IERC721-getApproved}.
               */
              function getApproved(uint256 tokenId) public view virtual override returns (address) {
                  require(_exists(tokenId), "ERC721: approved query for nonexistent token");
          
                  return _tokenApprovals[tokenId];
              }
          
              /**
               * @dev See {IERC721-setApprovalForAll}.
               */
              function setApprovalForAll(address operator, bool approved) public virtual override {
                  _setApprovalForAll(_msgSender(), operator, approved);
              }
          
              /**
               * @dev See {IERC721-isApprovedForAll}.
               */
              function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
                  return _operatorApprovals[owner][operator];
              }
          
              /**
               * @dev See {IERC721-transferFrom}.
               */
              function transferFrom(
                  address from,
                  address to,
                  uint256 tokenId
              ) public virtual override {
                  //solhint-disable-next-line max-line-length
                  require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
          
                  _transfer(from, to, tokenId);
              }
          
              /**
               * @dev See {IERC721-safeTransferFrom}.
               */
              function safeTransferFrom(
                  address from,
                  address to,
                  uint256 tokenId
              ) public virtual override {
                  safeTransferFrom(from, to, tokenId, "");
              }
          
              /**
               * @dev See {IERC721-safeTransferFrom}.
               */
              function safeTransferFrom(
                  address from,
                  address to,
                  uint256 tokenId,
                  bytes memory _data
              ) public virtual override {
                  require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
                  _safeTransfer(from, to, tokenId, _data);
              }
          
              /**
               * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
               * are aware of the ERC721 protocol to prevent tokens from being forever locked.
               *
               * `_data` is additional data, it has no specified format and it is sent in call to `to`.
               *
               * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
               * implement alternative mechanisms to perform token transfer, such as signature-based.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must exist and be owned by `from`.
               * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
               *
               * Emits a {Transfer} event.
               */
              function _safeTransfer(
                  address from,
                  address to,
                  uint256 tokenId,
                  bytes memory _data
              ) internal virtual {
                  _transfer(from, to, tokenId);
                  require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
              }
          
              /**
               * @dev Returns whether `tokenId` exists.
               *
               * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
               *
               * Tokens start existing when they are minted (`_mint`),
               * and stop existing when they are burned (`_burn`).
               */
              function _exists(uint256 tokenId) internal view virtual returns (bool) {
                  return _owners[tokenId] != address(0);
              }
          
              /**
               * @dev Returns whether `spender` is allowed to manage `tokenId`.
               *
               * Requirements:
               *
               * - `tokenId` must exist.
               */
              function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
                  require(_exists(tokenId), "ERC721: operator query for nonexistent token");
                  address owner = ERC721.ownerOf(tokenId);
                  return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
              }
          
              /**
               * @dev Safely mints `tokenId` and transfers it to `to`.
               *
               * Requirements:
               *
               * - `tokenId` must not exist.
               * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
               *
               * Emits a {Transfer} event.
               */
              function _safeMint(address to, uint256 tokenId) internal virtual {
                  _safeMint(to, tokenId, "");
              }
          
              /**
               * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
               * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
               */
              function _safeMint(
                  address to,
                  uint256 tokenId,
                  bytes memory _data
              ) internal virtual {
                  _mint(to, tokenId);
                  require(
                      _checkOnERC721Received(address(0), to, tokenId, _data),
                      "ERC721: transfer to non ERC721Receiver implementer"
                  );
              }
          
              /**
               * @dev Mints `tokenId` and transfers it to `to`.
               *
               * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
               *
               * Requirements:
               *
               * - `tokenId` must not exist.
               * - `to` cannot be the zero address.
               *
               * Emits a {Transfer} event.
               */
              function _mint(address to, uint256 tokenId) internal virtual {
                  require(to != address(0), "ERC721: mint to the zero address");
                  require(!_exists(tokenId), "ERC721: token already minted");
          
                  _beforeTokenTransfer(address(0), to, tokenId);
          
                  _balances[to] += 1;
                  _owners[tokenId] = to;
          
                  emit Transfer(address(0), to, tokenId);
          
                  _afterTokenTransfer(address(0), to, tokenId);
              }
          
              /**
               * @dev Destroys `tokenId`.
               * The approval is cleared when the token is burned.
               *
               * Requirements:
               *
               * - `tokenId` must exist.
               *
               * Emits a {Transfer} event.
               */
              function _burn(uint256 tokenId) internal virtual {
                  address owner = ERC721.ownerOf(tokenId);
          
                  _beforeTokenTransfer(owner, address(0), tokenId);
          
                  // Clear approvals
                  _approve(address(0), tokenId);
          
                  _balances[owner] -= 1;
                  delete _owners[tokenId];
          
                  emit Transfer(owner, address(0), tokenId);
          
                  _afterTokenTransfer(owner, address(0), tokenId);
              }
          
              /**
               * @dev Transfers `tokenId` from `from` to `to`.
               *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
               *
               * Requirements:
               *
               * - `to` cannot be the zero address.
               * - `tokenId` token must be owned by `from`.
               *
               * Emits a {Transfer} event.
               */
              function _transfer(
                  address from,
                  address to,
                  uint256 tokenId
              ) internal virtual {
                  require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
                  require(to != address(0), "ERC721: transfer to the zero address");
          
                  _beforeTokenTransfer(from, to, tokenId);
          
                  // Clear approvals from the previous owner
                  _approve(address(0), tokenId);
          
                  _balances[from] -= 1;
                  _balances[to] += 1;
                  _owners[tokenId] = to;
          
                  emit Transfer(from, to, tokenId);
          
                  _afterTokenTransfer(from, to, tokenId);
              }
          
              /**
               * @dev Approve `to` to operate on `tokenId`
               *
               * Emits a {Approval} event.
               */
              function _approve(address to, uint256 tokenId) internal virtual {
                  _tokenApprovals[tokenId] = to;
                  emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
              }
          
              /**
               * @dev Approve `operator` to operate on all of `owner` tokens
               *
               * Emits a {ApprovalForAll} event.
               */
              function _setApprovalForAll(
                  address owner,
                  address operator,
                  bool approved
              ) internal virtual {
                  require(owner != operator, "ERC721: approve to caller");
                  _operatorApprovals[owner][operator] = approved;
                  emit ApprovalForAll(owner, operator, approved);
              }
          
              /**
               * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
               * The call is not executed if the target address is not a contract.
               *
               * @param from address representing the previous owner of the given token ID
               * @param to target address that will receive the tokens
               * @param tokenId uint256 ID of the token to be transferred
               * @param _data bytes optional data to send along with the call
               * @return bool whether the call correctly returned the expected magic value
               */
              function _checkOnERC721Received(
                  address from,
                  address to,
                  uint256 tokenId,
                  bytes memory _data
              ) private returns (bool) {
                  if (to.isContract()) {
                      try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                          return retval == IERC721Receiver.onERC721Received.selector;
                      } catch (bytes memory reason) {
                          if (reason.length == 0) {
                              revert("ERC721: transfer to non ERC721Receiver implementer");
                          } else {
                              assembly {
                                  revert(add(32, reason), mload(reason))
                              }
                          }
                      }
                  } else {
                      return true;
                  }
              }
          
              /**
               * @dev Hook that is called before any token transfer. This includes minting
               * and burning.
               *
               * Calling conditions:
               *
               * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
               * transferred to `to`.
               * - When `from` is zero, `tokenId` will be minted for `to`.
               * - When `to` is zero, ``from``'s `tokenId` will be burned.
               * - `from` and `to` are never both zero.
               *
               * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
               */
              function _beforeTokenTransfer(
                  address from,
                  address to,
                  uint256 tokenId
              ) internal virtual {}
          
              /**
               * @dev Hook that is called after any transfer of tokens. This includes
               * minting and burning.
               *
               * Calling conditions:
               *
               * - when `from` and `to` are both non-zero.
               * - `from` and `to` are never both zero.
               *
               * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
               */
              function _afterTokenTransfer(
                  address from,
                  address to,
                  uint256 tokenId
              ) internal virtual {}
          }
          
          
          // File @openzeppelin/contracts/token/ERC721/extensions/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Burnable.sol)
          
          pragma solidity ^0.8.0;
          
          
          /**
           * @title ERC721 Burnable Token
           * @dev ERC721 Token that can be irreversibly burned (destroyed).
           */
          abstract contract ERC721Burnable is Context, ERC721 {
              /**
               * @dev Burns `tokenId`. See {ERC721-_burn}.
               *
               * Requirements:
               *
               * - The caller must own `tokenId` or be an approved operator.
               */
              function burn(uint256 tokenId) public virtual {
                  //solhint-disable-next-line max-line-length
                  require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721Burnable: caller is not owner nor approved");
                  _burn(tokenId);
              }
          }
          
          
          // File @openzeppelin/contracts/token/ERC721/extensions/[email protected]
          
          // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
          
          pragma solidity ^0.8.0;
          
          /**
           * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
           * @dev See https://eips.ethereum.org/EIPS/eip-721
           */
          interface IERC721Enumerable is IERC721 {
              /**
               * @dev Returns the total amount of tokens stored by the contract.
               */
              function totalSupply() external view returns (uint256);
          
              /**
               * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
               * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
               */
              function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256);
          
              /**
               * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
               * Use along with {totalSupply} to enumerate all tokens.
               */
              function tokenByIndex(uint256 index) external view returns (uint256);
          }
          
          
          // File @openzeppelin/contracts/utils/math/[email protected]
          
          // OpenZeppelin Contracts v4.4.1 (utils/math/SafeMath.sol)
          
          pragma solidity ^0.8.0;
          
          // CAUTION
          // This version of SafeMath should only be used with Solidity 0.8 or later,
          // because it relies on the compiler's built in overflow checks.
          
          /**
           * @dev Wrappers over Solidity's arithmetic operations.
           *
           * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
           * now has built in overflow checking.
           */
          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) {
                  unchecked {
                      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) {
                  unchecked {
                      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) {
                  unchecked {
                      // 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) {
                  unchecked {
                      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) {
                  unchecked {
                      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) {
                  return a + b;
              }
          
              /**
               * @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 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) {
                  return a * b;
              }
          
              /**
               * @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.
               *
               * Requirements:
               *
               * - The divisor cannot be zero.
               */
              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                  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) {
                  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) {
                  unchecked {
                      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.
               *
               * 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) {
                  unchecked {
                      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) {
                  unchecked {
                      require(b > 0, errorMessage);
                      return a % b;
                  }
              }
          }
          
          
          // File contracts/common/meta-transactions/ContentMixin.sol
          
          
          pragma solidity ^0.8.15;
          
          abstract contract ContextMixin {
              function msgSender() internal view returns (address payable sender) {
                  if (msg.sender == address(this)) {
                      bytes memory array = msg.data;
                      uint256 index = msg.data.length;
                      assembly {
                          // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
                          sender := and(
                              mload(add(array, index)),
                              0xffffffffffffffffffffffffffffffffffffffff
                          )
                      }
                  } else {
                      sender = payable(msg.sender);
                  }
                  return sender;
              }
          }
          
          
          // File contracts/common/meta-transactions/Initializable.sol
          
          
          pragma solidity ^0.8.15;
          
          contract Initializable {
              bool inited = false;
          
              modifier initializer() {
                  require(!inited, "already inited");
                  _;
                  inited = true;
              }
          }
          
          
          // File contracts/common/meta-transactions/EIP712Base.sol
          
          
          pragma solidity ^0.8.15;
          
          contract EIP712Base is Initializable {
              struct EIP712Domain {
                  string name;
                  string version;
                  address verifyingContract;
                  bytes32 salt;
              }
          
              string public constant ERC712_VERSION = "1";
          
              bytes32 internal constant EIP712_DOMAIN_TYPEHASH =
                  keccak256(
                      bytes(
                          "EIP712Domain(string name,string version,address verifyingContract,bytes32 salt)"
                      )
                  );
              bytes32 internal domainSeperator;
          
              // supposed to be called once while initializing.
              // one of the contracts that inherits this contract follows proxy pattern
              // so it is not possible to do this in a constructor
              function _initializeEIP712(string memory name) internal initializer {
                  _setDomainSeperator(name);
              }
          
              function _setDomainSeperator(string memory name) internal {
                  domainSeperator = keccak256(
                      abi.encode(
                          EIP712_DOMAIN_TYPEHASH,
                          keccak256(bytes(name)),
                          keccak256(bytes(ERC712_VERSION)),
                          address(this),
                          bytes32(getChainId())
                      )
                  );
              }
          
              function getDomainSeperator() public view returns (bytes32) {
                  return domainSeperator;
              }
          
              function getChainId() public view returns (uint256) {
                  uint256 id;
                  assembly {
                      id := chainid()
                  }
                  return id;
              }
          
              /**
               * Accept message hash and returns hash message in EIP712 compatible form
               * So that it can be used to recover signer from signature signed using EIP712 formatted data
               * https://eips.ethereum.org/EIPS/eip-712
               * "\\x19" makes the encoding deterministic
               * "\\x01" is the version byte to make it compatible to EIP-191
               */
              function toTypedMessageHash(bytes32 messageHash)
                  internal
                  view
                  returns (bytes32)
              {
                  return
                      keccak256(
                          abi.encodePacked("\x19\x01", getDomainSeperator(), messageHash)
                      );
              }
          }
          
          
          // File contracts/common/meta-transactions/NativeMetaTransaction.sol
          
          
          pragma solidity ^0.8.15;
          
          
          contract NativeMetaTransaction is EIP712Base {
              using SafeMath for uint256;
              bytes32 private constant META_TRANSACTION_TYPEHASH =
                  keccak256(
                      bytes(
                          "MetaTransaction(uint256 nonce,address from,bytes functionSignature)"
                      )
                  );
              event MetaTransactionExecuted(
                  address userAddress,
                  address payable relayerAddress,
                  bytes functionSignature
              );
              mapping(address => uint256) nonces;
          
              /*
               * Meta transaction structure.
               * No point of including value field here as if user is doing value transfer then he has the funds to pay for gas
               * He should call the desired function directly in that case.
               */
              struct MetaTransaction {
                  uint256 nonce;
                  address from;
                  bytes functionSignature;
              }
          
              function executeMetaTransaction(
                  address userAddress,
                  bytes memory functionSignature,
                  bytes32 sigR,
                  bytes32 sigS,
                  uint8 sigV
              ) public payable returns (bytes memory) {
                  MetaTransaction memory metaTx = MetaTransaction({
                      nonce: nonces[userAddress],
                      from: userAddress,
                      functionSignature: functionSignature
                  });
          
                  require(
                      verify(userAddress, metaTx, sigR, sigS, sigV),
                      "Signer and signature do not match"
                  );
          
                  // increase nonce for user (to avoid re-use)
                  nonces[userAddress] = nonces[userAddress].add(1);
          
                  emit MetaTransactionExecuted(
                      userAddress,
                      payable(msg.sender),
                      functionSignature
                  );
          
                  // Append userAddress and relayer address at the end to extract it from calling context
                  (bool success, bytes memory returnData) = address(this).call(
                      abi.encodePacked(functionSignature, userAddress)
                  );
                  require(success, "Function call not successful");
          
                  return returnData;
              }
          
              function hashMetaTransaction(MetaTransaction memory metaTx)
                  internal
                  pure
                  returns (bytes32)
              {
                  return
                      keccak256(
                          abi.encode(
                              META_TRANSACTION_TYPEHASH,
                              metaTx.nonce,
                              metaTx.from,
                              keccak256(metaTx.functionSignature)
                          )
                      );
              }
          
              function getNonce(address user) public view returns (uint256 nonce) {
                  nonce = nonces[user];
              }
          
              function verify(
                  address signer,
                  MetaTransaction memory metaTx,
                  bytes32 sigR,
                  bytes32 sigS,
                  uint8 sigV
              ) internal view returns (bool) {
                  require(signer != address(0), "NativeMetaTransaction: INVALID_SIGNER");
                  return
                      signer ==
                      ecrecover(
                          toTypedMessageHash(hashMetaTransaction(metaTx)),
                          sigV,
                          sigR,
                          sigS
                      );
              }
          }
          
          
          // File contracts/tokens/ERC721/ERC721Tradable.sol
          
          
          pragma solidity ^0.8.15;
          
          
          
          
          
          
          contract OwnableDelegateProxy {}
          
          /**
           * Used to delegate ownership of a contract to another address, to save on unneeded transactions to approve contract use for users
           */
          contract ProxyRegistry {
              mapping(address => OwnableDelegateProxy) public proxies;
          }
          
          /**
           * @title ERC721Tradable
           * ERC721Tradable - ERC721 contract that whitelists a trading address, and has minting functionality.
           */
          abstract contract ERC721Tradable is
              ERC721,
              ContextMixin,
              NativeMetaTransaction,
              Ownable
          {
              using SafeMath for uint256;
              using Counters for Counters.Counter;
          
              /**
               * We rely on the OZ Counter util to keep track of the next available ID.
               * We track the nextTokenId instead of the currentTokenId to save users on gas costs.
               * Read more about it here: https://shiny.mirror.xyz/OUampBbIz9ebEicfGnQf5At_ReMHlZy0tB4glb9xQ0E
               */
              Counters.Counter private _nextTokenId;
              address proxyRegistryAddress;
          
              constructor(
                  string memory _name,
                  string memory _symbol,
                  address _proxyRegistryAddress
              ) ERC721(_name, _symbol) {
                  proxyRegistryAddress = _proxyRegistryAddress;
                  // nextTokenId is initialized to 1, since starting at 0 leads to higher gas cost for the first minter
                  _nextTokenId.increment();
                  _initializeEIP712(_name);
              }
          
              /**
               * @dev Mints a token to an address with a tokenURI.
               * @param _to address of the future owner of the token
               */
              function mintTo(address _to) public virtual onlyOwner {
                  uint256 currentTokenId = _nextTokenId.current();
                  _nextTokenId.increment();
                  _safeMint(_to, currentTokenId);
              }
          
              /**
                  @dev Returns the total tokens minted so far.
                  1 is always subtracted from the Counter since it tracks the next available tokenId.
               */
              function totalSupply() public view virtual returns (uint256) {
                  return _nextTokenId.current() - 1;
              }
          
              function baseTokenURI() public view virtual returns (string memory);
          
              function tokenURI(uint256 _tokenId)
                  public
                  view
                  virtual
                  override
                  returns (string memory)
              {
                  return
                      string(
                          abi.encodePacked(baseTokenURI(), Strings.toString(_tokenId))
                      );
              }
          
              /**
               * Override isApprovedForAll to whitelist user's OpenSea proxy accounts to enable gas-less listings.
               */
              function isApprovedForAll(address owner, address operator)
                  public
                  view
                  virtual
                  override
                  returns (bool)
              {
                  // Whitelist OpenSea proxy contract for easy trading.
                  ProxyRegistry proxyRegistry = ProxyRegistry(proxyRegistryAddress);
                  if (address(proxyRegistry.proxies(owner)) == operator) {
                      return true;
                  }
          
                  return super.isApprovedForAll(owner, operator);
              }
          
              /**
               * This is used instead of msg.sender as transactions won't be sent by the original token owner, but by OpenSea.
               */
              function _msgSender()
                  internal
                  view
                  virtual
                  override
                  returns (address sender)
              {
                  return ContextMixin.msgSender();
              }
          }
          
          
          // File contracts/tokens/ERC721/WeAllSurvivedDeath.sol
          
          
          pragma solidity ^0.8.15;
          
          
          
          
          
          contract WeAllSurvivedDeath is
              AccessControl,
              ERC721Burnable,
              ERC721Tradable,
              IERC721Enumerable
          {
              using Strings for uint256;
              using Counters for Counters.Counter;
          
              struct TokenInfo {
                  uint256 tokenId;
                  string tokenURI;
              }
          
              bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
          
              Counters.Counter private _currentId;
              string private _baseTokenURI;
          
              // Array with all token ids, used for enumeration
              uint256[] private _allTokens;
          
              // Mapping from an owner address and the token index to the token ID
              mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
          
              // Mapping from token ID to index of the owner tokens list
              mapping(uint256 => uint256) private _ownedTokensIndex;
          
              // Mapping from token ID to position in the allTokens array
              mapping(uint256 => uint256) private _allTokensIndex;
          
              constructor(
                  string memory name_,
                  string memory symbol_,
                  string memory baseTokenURI_,
                  address proxyRegistryAddress
              ) ERC721Tradable(name_, symbol_, proxyRegistryAddress) {
                  _baseTokenURI = baseTokenURI_;
                  _setupRole(DEFAULT_ADMIN_ROLE, msg.sender);
                  _currentId.increment();
              }
          
              function isApprovedForAll(address owner, address operator)
                  public
                  view
                  override(IERC721, ERC721, ERC721Tradable)
                  returns (bool)
              {
                  return ERC721Tradable.isApprovedForAll(owner, operator);
              }
          
              function baseTokenURI() public view override returns (string memory) {
                  return _baseTokenURI;
              }
          
              function tokenURI(uint256 tokenId)
                  public
                  view
                  override(ERC721, ERC721Tradable)
                  returns (string memory)
              {
                  require(_exists(tokenId), "WeAllSurvivedDeath: token does not exist");
                  return
                      string(
                          abi.encodePacked(
                              _baseTokenURI,
                              Strings.toString(tokenId),
                              ".json"
                          )
                      );
              }
          
              function tokenOfOwnerByIndex(address owner, uint256 index)
                  public
                  view
                  virtual
                  returns (uint256)
              {
                  require(
                      index < ERC721.balanceOf(owner),
                      "WeAllSurvivedDeath: owner index out of bounds"
                  );
                  return _ownedTokens[owner][index];
              }
          
              function totalSupply()
                  public
                  view
                  virtual
                  override(ERC721Tradable, IERC721Enumerable)
                  returns (uint256)
              {
                  return _allTokens.length;
              }
          
              function tokenByIndex(uint256 index) public view virtual returns (uint256) {
                  require(
                      index < totalSupply(),
                      "WeAllSurvivedDeath: global index out of bounds"
                  );
                  return _allTokens[index];
              }
          
              function getOwnedTokens(
                  address user,
                  uint256 fromIndex,
                  uint256 toIndex
              ) external view returns (TokenInfo[] memory) {
                  if (balanceOf(user) == 0) return new TokenInfo[](0);
                  uint256 lastIndex = toIndex;
                  if (lastIndex >= balanceOf(user)) lastIndex = balanceOf(user) - 1;
                  require(
                      fromIndex <= lastIndex,
                      "WeAllSurvivedDeath: invalid query range"
                  );
                  uint256 numNFTs = lastIndex - fromIndex + 1;
                  TokenInfo[] memory ownedTokens = new TokenInfo[](numNFTs);
                  for (uint256 i = fromIndex; i <= lastIndex; i++) {
                      uint256 tokenId = tokenOfOwnerByIndex(user, i);
                      ownedTokens[i - fromIndex] = TokenInfo(tokenId, tokenURI(tokenId));
                  }
                  return ownedTokens;
              }
          
              function setBaseTokenURI(string memory baseTokenURI_) external {
                  require(
                      hasRole(DEFAULT_ADMIN_ROLE, msg.sender),
                      "WeAllSurvivedDeath: caller is not admin"
                  );
                  _baseTokenURI = baseTokenURI_;
              }
          
              function mintTo(address to) public override {
                  require(
                      hasRole(MINTER_ROLE, _msgSender()),
                      "WeAllSurvivedDeath: must have minter role to mint"
                  );
                  uint256 currentTokenId = _currentId.current();
                  _currentId.increment();
                  _safeMint(to, currentTokenId);
              }
          
              function supportsInterface(bytes4 interfaceId)
                  public
                  view
                  virtual
                  override(AccessControl, ERC721, IERC165)
                  returns (bool)
              {
                  return
                      interfaceId == type(IERC721Enumerable).interfaceId ||
                      AccessControl.supportsInterface(interfaceId) ||
                      ERC721.supportsInterface(interfaceId);
              }
          
              function _beforeTokenTransfer(
                  address from,
                  address to,
                  uint256 tokenId
              ) internal virtual override(ERC721) {
                  super._beforeTokenTransfer(from, to, tokenId);
                  if (from == address(0)) _addTokenToAllTokensEnumeration(tokenId);
                  else if (from != to) _removeTokenFromOwnerEnumeration(from, tokenId);
                  if (to == address(0)) _removeTokenFromAllTokensEnumeration(tokenId);
                  else if (to != from) _addTokenToOwnerEnumeration(to, tokenId);
              }
          
              function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
                  uint256 length = ERC721.balanceOf(to);
                  _ownedTokens[to][length] = tokenId;
                  _ownedTokensIndex[tokenId] = length;
              }
          
              function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
                  _allTokensIndex[tokenId] = _allTokens.length;
                  _allTokens.push(tokenId);
              }
          
              function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId)
                  private
              {
                  // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
                  // then delete the last slot (swap and pop).
          
                  uint256 lastTokenIndex = ERC721.balanceOf(from) - 1;
                  uint256 tokenIndex = _ownedTokensIndex[tokenId];
          
                  // When the token to delete is the last token, the swap operation is unnecessary
                  if (tokenIndex != lastTokenIndex) {
                      uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
          
                      _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
                      _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
                  }
          
                  // This also deletes the contents at the last position of the array
                  delete _ownedTokensIndex[tokenId];
                  delete _ownedTokens[from][lastTokenIndex];
              }
          
              function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
                  // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
                  // then delete the last slot (swap and pop).
          
                  uint256 lastTokenIndex = _allTokens.length - 1;
                  uint256 tokenIndex = _allTokensIndex[tokenId];
          
                  // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
                  // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
                  // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
                  uint256 lastTokenId = _allTokens[lastTokenIndex];
          
                  _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
                  _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
          
                  // This also deletes the contents at the last position of the array
                  delete _allTokensIndex[tokenId];
                  _allTokens.pop();
              }
          
              function _msgSender()
                  internal
                  view
                  override(Context, ERC721Tradable)
                  returns (address)
              {
                  return ERC721Tradable._msgSender();
              }
          }
          
          
          // File contracts/WASDMinting.sol
          
          
          pragma solidity ^0.8.15;
          
          
          
          
          contract WASDMinting is Ownable, Pausable {
              using ECDSA for bytes32;
          
              struct MintingRole {
                  uint256 roleId;
                  string roleName;
                  uint256 mintLimit; // the maximum number of times each participant of this role can mint
              }
          
              struct PhaseInfo {
                  string metadata; // the general information of this phase
                  uint256 duration; // the duration of this phase in seconds
                  uint256 mintLimit; // the maximum number of times each participant can mint at this phase
              }
          
              struct ParticipantInfo {
                  uint256 roleId;
                  uint256 mintCount;
              }
          
              WeAllSurvivedDeath public WASD;
              uint256 public wasdLimit;
              uint256 public totalMintCount;
              uint256 public startingTime;
              uint256 private _deployedTime;
              PhaseInfo[] private _phaseInfos;
              MintingRole[] private _mintingRoles;
              mapping(uint256 => mapping(uint256 => bool)) private _rolePermission; // (phase ID + role ID) => permission
              mapping(address => ParticipantInfo) private _participantInfos;
              mapping(uint256 => uint256[]) private _allowedInPhases; // role ID => [phase IDs]
              mapping(uint256 => uint256) private _availableSlotsForRole; // the maximum number of participants who can have this role
              mapping(address => bool) private _operators;
          
              event MintingRoleCreated(
                  uint256 roleId,
                  string roleName,
                  uint256 mintLimit
              );
          
              constructor(
                  address wasdNFT,
                  uint256 wasdLimit_,
                  uint256 startingTime_,
                  string[] memory metadatas,
                  uint256[] memory durations,
                  uint256[] memory mintLimits
              ) Ownable() {
                  _operators[msg.sender] = true;
                  WASD = WeAllSurvivedDeath(wasdNFT);
                  wasdLimit = wasdLimit_;
                  startingTime = startingTime_;
                  _deployedTime = block.timestamp;
                  _availableSlotsForRole[0] = type(uint256).max;
                  _mintingRoles.push(MintingRole(0, "Community", 1));
                  require(
                      metadatas.length == durations.length,
                      "WASDMinting: lengths mismatch"
                  );
                  require(
                      metadatas.length == mintLimits.length,
                      "WASDMinting: lengths mismatch"
                  );
                  _phaseInfos.push(PhaseInfo("", startingTime_ - block.timestamp, 0));
                  for (uint256 i = 0; i < metadatas.length; i++) {
                      require(durations[i] >= 5 minutes, "WASDMinting: phase too short");
                      require(
                          mintLimits[i] > 0,
                          "WASDMinting: mint limit must be greater than zero"
                      );
                      _phaseInfos.push(
                          PhaseInfo(metadatas[i], durations[i], mintLimits[i])
                      );
                  }
              }
          
              modifier onlyOperators() {
                  require(_operators[msg.sender], "WASDMinting: caller is not operator");
                  _;
              }
          
              function getPhaseInfo() external view returns (PhaseInfo[] memory) {
                  uint256 numPhases = _phaseInfos.length - 1;
                  PhaseInfo[] memory phases = new PhaseInfo[](numPhases);
                  for (uint256 i = 0; i < numPhases; i++) phases[i] = _phaseInfos[i + 1];
                  return phases;
              }
          
              function getCurrentPhase() public view returns (uint256) {
                  uint256 elapsedTime = block.timestamp - _deployedTime;
                  for (uint256 phase = 0; phase < _phaseInfos.length; phase++)
                      if (elapsedTime >= _phaseInfos[phase].duration)
                          elapsedTime -= _phaseInfos[phase].duration;
                      else return phase;
                  return _phaseInfos.length;
              }
          
              function getRoles() external view returns (MintingRole[] memory) {
                  return _mintingRoles;
              }
          
              function getParticipantInfo(address participant)
                  public
                  view
                  returns (
                      uint256 roleId,
                      string memory roleName,
                      uint256 mintLimit,
                      uint256 mintCount,
                      uint256 availableMintCount,
                      uint256[] memory allowedInPhases
                  )
              {
                  require(
                      getCurrentPhase() < _phaseInfos.length,
                      "WASDMinting: minting time is over"
                  );
                  roleId = _participantInfos[participant].roleId;
                  roleName = _mintingRoles[roleId].roleName;
                  mintLimit = _mintingRoles[roleId].mintLimit;
                  mintCount = _participantInfos[participant].mintCount;
                  allowedInPhases = _allowedInPhases[roleId];
                  if (!_rolePermission[getCurrentPhase()][roleId]) availableMintCount = 0;
                  else {
                      require(
                          _participantInfos[participant].mintCount <=
                              _mintingRoles[roleId].mintLimit,
                          "WASDMinting: mint count exceeds limit"
                      );
                      availableMintCount =
                          _mintingRoles[roleId].mintLimit -
                          _participantInfos[participant].mintCount;
                      if (availableMintCount > _phaseInfos[getCurrentPhase()].mintLimit)
                          availableMintCount = _phaseInfos[getCurrentPhase()].mintLimit;
                  }
              }
          
              function setOperators(address[] memory operators, bool[] memory isOperators)
                  external
                  onlyOwner
              {
                  require(
                      operators.length == isOperators.length,
                      "WASDMinting: lengths mismatch"
                  );
                  for (uint256 i = 0; i < operators.length; i++)
                      _operators[operators[i]] = isOperators[i];
              }
          
              function createMintingRoles(
                  string[] memory roleNames,
                  uint256[] memory mintLimits,
                  uint256[] memory roleLimits
              ) external onlyOperators {
                  require(
                      roleNames.length == mintLimits.length,
                      "WASDMinting: lengths mismatch"
                  );
                  require(
                      roleNames.length == roleLimits.length,
                      "WASDMinting: lengths mismatch"
                  );
                  for (uint256 i = 0; i < roleNames.length; i++) {
                      require(
                          mintLimits[i] > 0,
                          "WASDMinting: mint limit must be greater than zero"
                      );
                      require(
                          roleLimits[i] > 0,
                          "WASDMinting: role limit must be greater than zero"
                      );
                      uint256 roleId = _mintingRoles.length;
                      _availableSlotsForRole[roleId] = roleLimits[i];
                      _mintingRoles.push(
                          MintingRole(roleId, roleNames[i], mintLimits[i])
                      );
                      emit MintingRoleCreated(roleId, roleNames[i], mintLimits[i]);
                  }
              }
          
              function addRolesToPhases(
                  uint256[] memory phaseIds,
                  uint256[][] memory roleIds
              ) external onlyOperators {
                  require(
                      phaseIds.length == roleIds.length,
                      "WASDMinting: lengths mismatch"
                  );
                  for (uint256 i = 0; i < phaseIds.length; i++) {
                      require(
                          phaseIds[i] < _phaseInfos.length,
                          "WASDMinting: invalid phase ID"
                      );
                      for (uint256 j = 0; j < roleIds[i].length; j++) {
                          require(
                              roleIds[i][j] < _mintingRoles.length,
                              "WASDMinting: invalid role ID"
                          );
                          _rolePermission[phaseIds[i]][roleIds[i][j]] = true;
                          _allowedInPhases[roleIds[i][j]].push(phaseIds[i]);
                      }
                  }
              }
          
              function mintWASD(
                  uint256 roleId,
                  bytes calldata signature,
                  uint256 quantity
              ) external whenNotPaused {
                  // Validate basic information
                  require(
                      getCurrentPhase() < _phaseInfos.length,
                      "WASDMinting: minting time is over"
                  );
                  require(
                      _participantInfos[msg.sender].roleId == 0,
                      "WASDMinting: participant already granted minting role"
                  );
                  require(
                      _participantInfos[msg.sender].mintCount == 0,
                      "WASDMinting: not the first mint"
                  );
                  require(roleId < _mintingRoles.length, "WASDMinting: invalid role ID");
                  require(
                      _availableSlotsForRole[roleId] > 0,
                      "WASDMinting: role limit reached"
                  );
          
                  // Validate operator's signature
                  bytes32 hash = keccak256(abi.encodePacked(msg.sender, roleId));
                  bytes32 messageHash = hash.toEthSignedMessageHash();
                  address signer = messageHash.recover(signature);
                  require(_operators[signer], "WASDMinting: invalid signer");
          
                  // Validate mint count
                  require(
                      totalMintCount + quantity <= wasdLimit,
                      "WASDMinting: total mint limit reached"
                  );
                  uint256 availableMintCount = 0;
                  if (_rolePermission[getCurrentPhase()][roleId]) {
                      availableMintCount = _mintingRoles[roleId].mintLimit;
                      if (availableMintCount > _phaseInfos[getCurrentPhase()].mintLimit)
                          availableMintCount = _phaseInfos[getCurrentPhase()].mintLimit;
                  }
                  require(
                      quantity <= availableMintCount,
                      "WASDMinting: personal mint limit at this phase reached"
                  );
          
                  // Grant role and mint WASDs
                  _availableSlotsForRole[roleId]--;
                  _participantInfos[msg.sender].roleId = roleId;
                  _participantInfos[msg.sender].mintCount = quantity;
                  totalMintCount += quantity;
                  for (uint256 i = 0; i < quantity; i++) WASD.mintTo(msg.sender);
              }
          
              function mintWASD(uint256 quantity) external whenNotPaused {
                  require(
                      _participantInfos[msg.sender].mintCount > 0,
                      "WASDMinting: first mint - undetected role"
                  );
                  (, , , , uint256 availableMintCount, ) = getParticipantInfo(msg.sender);
                  require(
                      quantity <= availableMintCount,
                      "WASDMinting: personal mint limit at this phase reached"
                  );
                  require(
                      totalMintCount + quantity <= wasdLimit,
                      "WASDMinting: total mint limit reached"
                  );
                  _participantInfos[msg.sender].mintCount += quantity;
                  totalMintCount += quantity;
                  for (uint256 i = 0; i < quantity; i++) WASD.mintTo(msg.sender);
              }
          
              function pause() external onlyOwner {
                  _pause();
              }
          
              function unpause() external onlyOwner {
                  _unpause();
              }
          }

          File 3 of 6: X2Y2_r1
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import './IDelegate.sol';
          import './IWETHUpgradable.sol';
          import './MarketConsts.sol';
          import '@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol';
          import '@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol';
          import '@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol';
          import '@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol';
          import '@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol';
          import '@openzeppelin/contracts/utils/cryptography/ECDSA.sol';
          interface IX2Y2Run {
              function run1(
                  Market.Order memory order,
                  Market.SettleShared memory shared,
                  Market.SettleDetail memory detail
              ) external returns (uint256);
          }
          contract X2Y2_r1 is
              Initializable,
              ReentrancyGuardUpgradeable,
              OwnableUpgradeable,
              PausableUpgradeable,
              IX2Y2Run
          {
              using SafeERC20Upgradeable for IERC20Upgradeable;
              event EvProfit(bytes32 itemHash, address currency, address to, uint256 amount);
              event EvAuctionRefund(
                  bytes32 indexed itemHash,
                  address currency,
                  address to,
                  uint256 amount,
                  uint256 incentive
              );
              event EvInventory(
                  bytes32 indexed itemHash,
                  address maker,
                  address taker,
                  uint256 orderSalt,
                  uint256 settleSalt,
                  uint256 intent,
                  uint256 delegateType,
                  uint256 deadline,
                  IERC20Upgradeable currency,
                  bytes dataMask,
                  Market.OrderItem item,
                  Market.SettleDetail detail
              );
              event EvSigner(address signer, bool isRemoval);
              event EvDelegate(address delegate, bool isRemoval);
              event EvFeeCapUpdate(uint256 newValue);
              event EvCancel(bytes32 indexed itemHash);
              event EvFailure(uint256 index, bytes error);
              mapping(address => bool) public delegates;
              mapping(address => bool) public signers;
              mapping(bytes32 => Market.InvStatus) public inventoryStatus;
              mapping(bytes32 => Market.OngoingAuction) public ongoingAuctions;
              uint256 public constant RATE_BASE = 1e6;
              uint256 public feeCapPct;
              IWETHUpgradable public weth;
              receive() external payable {}
              function pause() public onlyOwner {
                  _pause();
              }
              function unpause() public onlyOwner {
                  _unpause();
              }
              function initialize(uint256 feeCapPct_, address weth_) public initializer {
                  feeCapPct = feeCapPct_;
                  weth = IWETHUpgradable(weth_);
                  __ReentrancyGuard_init_unchained();
                  __Pausable_init_unchained();
                  __Ownable_init_unchained();
              }
              function updateFeeCap(uint256 val) public virtual onlyOwner {
                  feeCapPct = val;
                  emit EvFeeCapUpdate(val);
              }
              function updateSigners(address[] memory toAdd, address[] memory toRemove)
                  public
                  virtual
                  onlyOwner
              {
                  for (uint256 i = 0; i < toAdd.length; i++) {
                      signers[toAdd[i]] = true;
                      emit EvSigner(toAdd[i], false);
                  }
                  for (uint256 i = 0; i < toRemove.length; i++) {
                      delete signers[toRemove[i]];
                      emit EvSigner(toRemove[i], true);
                  }
              }
              function updateDelegates(address[] memory toAdd, address[] memory toRemove)
                  public
                  virtual
                  onlyOwner
              {
                  for (uint256 i = 0; i < toAdd.length; i++) {
                      delegates[toAdd[i]] = true;
                      emit EvDelegate(toAdd[i], false);
                  }
                  for (uint256 i = 0; i < toRemove.length; i++) {
                      delete delegates[toRemove[i]];
                      emit EvDelegate(toRemove[i], true);
                  }
              }
              function cancel(
                  bytes32[] memory itemHashes,
                  uint256 deadline,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) public virtual nonReentrant whenNotPaused {
                  require(deadline > block.timestamp, 'deadline reached');
                  bytes32 hash = keccak256(abi.encode(itemHashes.length, itemHashes, deadline));
                  address signer = ECDSA.recover(hash, v, r, s);
                  require(signers[signer], 'Input signature error');
                  for (uint256 i = 0; i < itemHashes.length; i++) {
                      bytes32 h = itemHashes[i];
                      if (inventoryStatus[h] == Market.InvStatus.NEW) {
                          inventoryStatus[h] = Market.InvStatus.CANCELLED;
                          emit EvCancel(h);
                      }
                  }
              }
              function run(Market.RunInput memory input) public payable virtual nonReentrant whenNotPaused {
                  require(input.shared.deadline > block.timestamp, 'input deadline reached');
                  require(msg.sender == input.shared.user, 'sender does not match');
                  _verifyInputSignature(input);
                  uint256 amountEth = msg.value;
                  if (input.shared.amountToWeth > 0) {
                      uint256 amt = input.shared.amountToWeth;
                      weth.deposit{value: amt}();
                      SafeERC20Upgradeable.safeTransfer(weth, msg.sender, amt);
                      amountEth -= amt;
                  }
                  if (input.shared.amountToEth > 0) {
                      uint256 amt = input.shared.amountToEth;
                      SafeERC20Upgradeable.safeTransferFrom(weth, msg.sender, address(this), amt);
                      weth.withdraw(amt);
                      amountEth += amt;
                  }
                  for (uint256 i = 0; i < input.orders.length; i++) {
                      _verifyOrderSignature(input.orders[i]);
                  }
                  for (uint256 i = 0; i < input.details.length; i++) {
                      Market.SettleDetail memory detail = input.details[i];
                      Market.Order memory order = input.orders[detail.orderIdx];
                      if (input.shared.canFail) {
                          try IX2Y2Run(address(this)).run1(order, input.shared, detail) returns (
                              uint256 ethPayment
                          ) {
                              amountEth -= ethPayment;
                          } catch Error(string memory _err) {
                              emit EvFailure(i, bytes(_err));
                          } catch (bytes memory _err) {
                              emit EvFailure(i, _err);
                          }
                      } else {
                          amountEth -= _run(order, input.shared, detail);
                      }
                  }
                  if (amountEth > 0) {
                      payable(msg.sender).transfer(amountEth);
                  }
              }
              function run1(
                  Market.Order memory order,
                  Market.SettleShared memory shared,
                  Market.SettleDetail memory detail
              ) external virtual returns (uint256) {
                  require(msg.sender == address(this), 'unsafe call');
                  return _run(order, shared, detail);
              }
              function _hashItem(Market.Order memory order, Market.OrderItem memory item)
                  internal
                  view
                  virtual
                  returns (bytes32)
              {
                  return
                      keccak256(
                          abi.encode(
                              order.salt,
                              order.user,
                              order.network,
                              order.intent,
                              order.delegateType,
                              order.deadline,
                              order.currency,
                              order.dataMask,
                              item
                          )
                      );
              }
              function _emitInventory(
                  bytes32 itemHash,
                  Market.Order memory order,
                  Market.OrderItem memory item,
                  Market.SettleShared memory shared,
                  Market.SettleDetail memory detail
              ) internal virtual {
                  emit EvInventory(
                      itemHash,
                      order.user,
                      shared.user,
                      order.salt,
                      shared.salt,
                      order.intent,
                      order.delegateType,
                      order.deadline,
                      order.currency,
                      order.dataMask,
                      item,
                      detail
                  );
              }
              function _run(
                  Market.Order memory order,
                  Market.SettleShared memory shared,
                  Market.SettleDetail memory detail
              ) internal virtual returns (uint256) {
                  uint256 nativeAmount = 0;
                  Market.OrderItem memory item = order.items[detail.itemIdx];
                  bytes32 itemHash = _hashItem(order, item);
                  {
                      require(itemHash == detail.itemHash, 'item hash does not match');
                      require(order.network == block.chainid, 'wrong network');
                      require(
                          address(detail.executionDelegate) != address(0) &&
                              delegates[address(detail.executionDelegate)],
                          'unknown delegate'
                      );
                  }
                  bytes memory data = item.data;
                  {
                      if (order.dataMask.length > 0 && detail.dataReplacement.length > 0) {
                          _arrayReplace(data, detail.dataReplacement, order.dataMask);
                      }
                  }
                  if (detail.op == Market.Op.COMPLETE_SELL_OFFER) {
                      require(inventoryStatus[itemHash] == Market.InvStatus.NEW, 'order already exists');
                      require(order.intent == Market.INTENT_SELL, 'intent != sell');
                      _assertDelegation(order, detail);
                      require(order.deadline > block.timestamp, 'deadline reached');
                      require(detail.price >= item.price, 'underpaid');
                      nativeAmount = _takePayment(itemHash, order.currency, shared.user, detail.price);
                      require(
                          detail.executionDelegate.executeSell(order.user, shared.user, data),
                          'delegation error'
                      );
                      _distributeFeeAndProfit(
                          itemHash,
                          order.user,
                          order.currency,
                          detail,
                          detail.price,
                          detail.price
                      );
                      inventoryStatus[itemHash] = Market.InvStatus.COMPLETE;
                  } else if (detail.op == Market.Op.COMPLETE_BUY_OFFER) {
                      require(inventoryStatus[itemHash] == Market.InvStatus.NEW, 'order already exists');
                      require(order.intent == Market.INTENT_BUY, 'intent != buy');
                      _assertDelegation(order, detail);
                      require(order.deadline > block.timestamp, 'deadline reached');
                      require(item.price == detail.price, 'price not match');
                      require(!_isNative(order.currency), 'native token not supported');
                      nativeAmount = _takePayment(itemHash, order.currency, order.user, detail.price);
                      require(
                          detail.executionDelegate.executeBuy(shared.user, order.user, data),
                          'delegation error'
                      );
                      _distributeFeeAndProfit(
                          itemHash,
                          shared.user,
                          order.currency,
                          detail,
                          detail.price,
                          detail.price
                      );
                      inventoryStatus[itemHash] = Market.InvStatus.COMPLETE;
                  } else if (detail.op == Market.Op.CANCEL_OFFER) {
                      require(inventoryStatus[itemHash] == Market.InvStatus.NEW, 'unable to cancel');
                      require(order.deadline > block.timestamp, 'deadline reached');
                      inventoryStatus[itemHash] = Market.InvStatus.CANCELLED;
                      emit EvCancel(itemHash);
                  } else if (detail.op == Market.Op.BID) {
                      require(order.intent == Market.INTENT_AUCTION, 'intent != auction');
                      _assertDelegation(order, detail);
                      bool firstBid = false;
                      if (ongoingAuctions[itemHash].bidder == address(0)) {
                          require(inventoryStatus[itemHash] == Market.InvStatus.NEW, 'order already exists');
                          require(order.deadline > block.timestamp, 'auction ended');
                          require(detail.price >= item.price, 'underpaid');
                          firstBid = true;
                          ongoingAuctions[itemHash] = Market.OngoingAuction({
                              price: detail.price,
                              netPrice: detail.price,
                              bidder: shared.user,
                              endAt: order.deadline
                          });
                          inventoryStatus[itemHash] = Market.InvStatus.AUCTION;
                          require(
                              detail.executionDelegate.executeBid(order.user, address(0), shared.user, data),
                              'delegation error'
                          );
                      }
                      Market.OngoingAuction storage auc = ongoingAuctions[itemHash];
                      require(auc.endAt > block.timestamp, 'auction ended');
                      nativeAmount = _takePayment(itemHash, order.currency, shared.user, detail.price);
                      if (!firstBid) {
                          require(
                              inventoryStatus[itemHash] == Market.InvStatus.AUCTION,
                              'order is not auction'
                          );
                          require(
                              detail.price - auc.price >= (auc.price * detail.aucMinIncrementPct) / RATE_BASE,
                              'underbid'
                          );
                          uint256 bidRefund = auc.netPrice;
                          uint256 incentive = (detail.price * detail.bidIncentivePct) / RATE_BASE;
                          if (bidRefund + incentive > 0) {
                              _transferTo(order.currency, auc.bidder, bidRefund + incentive);
                              emit EvAuctionRefund(
                                  itemHash,
                                  address(order.currency),
                                  auc.bidder,
                                  bidRefund,
                                  incentive
                              );
                          }
                          require(
                              detail.executionDelegate.executeBid(order.user, auc.bidder, shared.user, data),
                              'delegation error'
                          );
                          auc.price = detail.price;
                          auc.netPrice = detail.price - incentive;
                          auc.bidder = shared.user;
                      }
                      if (block.timestamp + detail.aucIncDurationSecs > auc.endAt) {
                          auc.endAt += detail.aucIncDurationSecs;
                      }
                  } else if (
                      detail.op == Market.Op.REFUND_AUCTION ||
                      detail.op == Market.Op.REFUND_AUCTION_STUCK_ITEM
                  ) {
                      require(
                          inventoryStatus[itemHash] == Market.InvStatus.AUCTION,
                          'cannot cancel non-auction order'
                      );
                      Market.OngoingAuction storage auc = ongoingAuctions[itemHash];
                      if (auc.netPrice > 0) {
                          _transferTo(order.currency, auc.bidder, auc.netPrice);
                          emit EvAuctionRefund(
                              itemHash,
                              address(order.currency),
                              auc.bidder,
                              auc.netPrice,
                              0
                          );
                      }
                      _assertDelegation(order, detail);
                      if (detail.op == Market.Op.REFUND_AUCTION) {
                          require(
                              detail.executionDelegate.executeAuctionRefund(order.user, auc.bidder, data),
                              'delegation error'
                          );
                      }
                      delete ongoingAuctions[itemHash];
                      inventoryStatus[itemHash] = Market.InvStatus.REFUNDED;
                  } else if (detail.op == Market.Op.COMPLETE_AUCTION) {
                      require(
                          inventoryStatus[itemHash] == Market.InvStatus.AUCTION,
                          'cannot complete non-auction order'
                      );
                      _assertDelegation(order, detail);
                      Market.OngoingAuction storage auc = ongoingAuctions[itemHash];
                      require(block.timestamp >= auc.endAt, 'auction not finished yet');
                      require(
                          detail.executionDelegate.executeAuctionComplete(order.user, auc.bidder, data),
                          'delegation error'
                      );
                      _distributeFeeAndProfit(
                          itemHash,
                          order.user,
                          order.currency,
                          detail,
                          auc.price,
                          auc.netPrice
                      );
                      inventoryStatus[itemHash] = Market.InvStatus.COMPLETE;
                      delete ongoingAuctions[itemHash];
                  } else {
                      revert('unknown op');
                  }
                  _emitInventory(itemHash, order, item, shared, detail);
                  return nativeAmount;
              }
              function _assertDelegation(Market.Order memory order, Market.SettleDetail memory detail)
                  internal
                  view
                  virtual
              {
                  require(
                      detail.executionDelegate.delegateType() == order.delegateType,
                      'delegation type error'
                  );
              }
              // modifies `src`
              function _arrayReplace(
                  bytes memory src,
                  bytes memory replacement,
                  bytes memory mask
              ) internal view virtual {
                  require(src.length == replacement.length);
                  require(src.length == mask.length);
                  for (uint256 i = 0; i < src.length; i++) {
                      if (mask[i] != 0) {
                          src[i] = replacement[i];
                      }
                  }
              }
              function _verifyInputSignature(Market.RunInput memory input) internal view virtual {
                  bytes32 hash = keccak256(abi.encode(input.shared, input.details.length, input.details));
                  address signer = ECDSA.recover(hash, input.v, input.r, input.s);
                  require(signers[signer], 'Input signature error');
              }
              function _verifyOrderSignature(Market.Order memory order) internal view virtual {
                  address orderSigner;
                  if (order.signVersion == Market.SIGN_V1) {
                      bytes32 orderHash = keccak256(
                          abi.encode(
                              order.salt,
                              order.user,
                              order.network,
                              order.intent,
                              order.delegateType,
                              order.deadline,
                              order.currency,
                              order.dataMask,
                              order.items.length,
                              order.items
                          )
                      );
                      orderSigner = ECDSA.recover(
                          ECDSA.toEthSignedMessageHash(orderHash),
                          order.v,
                          order.r,
                          order.s
                      );
                  } else {
                      revert('unknown signature version');
                  }
                  require(orderSigner == order.user, 'Order signature does not match');
              }
              function _isNative(IERC20Upgradeable currency) internal view virtual returns (bool) {
                  return address(currency) == address(0);
              }
              function _takePayment(
                  bytes32 itemHash,
                  IERC20Upgradeable currency,
                  address from,
                  uint256 amount
              ) internal virtual returns (uint256) {
                  if (amount > 0) {
                      if (_isNative(currency)) {
                          return amount;
                      } else {
                          currency.safeTransferFrom(from, address(this), amount);
                      }
                  }
                  return 0;
              }
              function _transferTo(
                  IERC20Upgradeable currency,
                  address to,
                  uint256 amount
              ) internal virtual {
                  if (amount > 0) {
                      if (_isNative(currency)) {
                          AddressUpgradeable.sendValue(payable(to), amount);
                      } else {
                          currency.safeTransfer(to, amount);
                      }
                  }
              }
              function _distributeFeeAndProfit(
                  bytes32 itemHash,
                  address seller,
                  IERC20Upgradeable currency,
                  Market.SettleDetail memory sd,
                  uint256 price,
                  uint256 netPrice
              ) internal virtual {
                  require(price >= netPrice, 'price error');
                  uint256 payment = netPrice;
                  uint256 totalFeePct;
                  for (uint256 i = 0; i < sd.fees.length; i++) {
                      Market.Fee memory fee = sd.fees[i];
                      totalFeePct += fee.percentage;
                      uint256 amount = (price * fee.percentage) / RATE_BASE;
                      payment -= amount;
                      _transferTo(currency, fee.to, amount);
                  }
                  require(feeCapPct >= totalFeePct, 'total fee cap exceeded');
                  _transferTo(currency, seller, payment);
                  emit EvProfit(itemHash, address(currency), seller, payment);
              }
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          interface IDelegate {
              function delegateType() external view returns (uint256);
              function executeSell(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external returns (bool);
              function executeBuy(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external returns (bool);
              function executeBid(
                  address seller,
                  address previousBidder,
                  address bidder,
                  bytes calldata data
              ) external returns (bool);
              function executeAuctionComplete(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external returns (bool);
              function executeAuctionRefund(
                  address seller,
                  address lastBidder,
                  bytes calldata data
              ) external returns (bool);
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import '@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol';
          interface IWETHUpgradable is IERC20Upgradeable {
              function deposit() external payable;
              function withdraw(uint256 wad) external;
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import './IDelegate.sol';
          import './IWETHUpgradable.sol';
          library Market {
              uint256 constant INTENT_SELL = 1;
              uint256 constant INTENT_AUCTION = 2;
              uint256 constant INTENT_BUY = 3;
              uint8 constant SIGN_V1 = 1;
              uint8 constant SIGN_V3 = 3;
              struct OrderItem {
                  uint256 price;
                  bytes data;
              }
              struct Order {
                  uint256 salt;
                  address user;
                  uint256 network;
                  uint256 intent;
                  uint256 delegateType;
                  uint256 deadline;
                  IERC20Upgradeable currency;
                  bytes dataMask;
                  OrderItem[] items;
                  // signature
                  bytes32 r;
                  bytes32 s;
                  uint8 v;
                  uint8 signVersion;
              }
              struct Fee {
                  uint256 percentage;
                  address to;
              }
              struct SettleDetail {
                  Market.Op op;
                  uint256 orderIdx;
                  uint256 itemIdx;
                  uint256 price;
                  bytes32 itemHash;
                  IDelegate executionDelegate;
                  bytes dataReplacement;
                  uint256 bidIncentivePct;
                  uint256 aucMinIncrementPct;
                  uint256 aucIncDurationSecs;
                  Fee[] fees;
              }
              struct SettleShared {
                  uint256 salt;
                  uint256 deadline;
                  uint256 amountToEth;
                  uint256 amountToWeth;
                  address user;
                  bool canFail;
              }
              struct RunInput {
                  Order[] orders;
                  SettleDetail[] details;
                  SettleShared shared;
                  // signature
                  bytes32 r;
                  bytes32 s;
                  uint8 v;
              }
              struct OngoingAuction {
                  uint256 price;
                  uint256 netPrice;
                  uint256 endAt;
                  address bidder;
              }
              enum InvStatus {
                  NEW,
                  AUCTION,
                  COMPLETE,
                  CANCELLED,
                  REFUNDED
              }
              enum Op {
                  INVALID,
                  // off-chain
                  COMPLETE_SELL_OFFER,
                  COMPLETE_BUY_OFFER,
                  CANCEL_OFFER,
                  // auction
                  BID,
                  COMPLETE_AUCTION,
                  REFUND_AUCTION,
                  REFUND_AUCTION_STUCK_ITEM
              }
              enum DelegationType {
                  INVALID,
                  ERC721,
                  ERC1155
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
          pragma solidity ^0.8.0;
          import "../utils/ContextUpgradeable.sol";
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              function __Ownable_init() internal onlyInitializing {
                  __Context_init_unchained();
                  __Ownable_init_unchained();
              }
              function __Ownable_init_unchained() internal onlyInitializing {
                  _transferOwnership(_msgSender());
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  _transferOwnership(address(0));
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  _transferOwnership(newOwner);
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Internal function without access restriction.
               */
              function _transferOwnership(address newOwner) internal virtual {
                  address oldOwner = _owner;
                  _owner = newOwner;
                  emit OwnershipTransferred(oldOwner, newOwner);
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (proxy/utils/Initializable.sol)
          pragma solidity ^0.8.0;
          import "../../utils/AddressUpgradeable.sol";
          /**
           * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
           * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
           * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
           * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
           *
           * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
           * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
           *
           * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
           * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
           *
           * [CAUTION]
           * ====
           * Avoid leaving a contract uninitialized.
           *
           * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
           * contract, which may impact the proxy. To initialize the implementation contract, you can either invoke the
           * initializer manually, or you can include a constructor to automatically mark it as initialized when it is deployed:
           *
           * [.hljs-theme-light.nopadding]
           * ```
           * /// @custom:oz-upgrades-unsafe-allow constructor
           * constructor() initializer {}
           * ```
           * ====
           */
          abstract contract Initializable {
              /**
               * @dev Indicates that the contract has been initialized.
               */
              bool private _initialized;
              /**
               * @dev Indicates that the contract is in the process of being initialized.
               */
              bool private _initializing;
              /**
               * @dev Modifier to protect an initializer function from being invoked twice.
               */
              modifier initializer() {
                  // If the contract is initializing we ignore whether _initialized is set in order to support multiple
                  // inheritance patterns, but we only do this in the context of a constructor, because in other contexts the
                  // contract may have been reentered.
                  require(_initializing ? _isConstructor() : !_initialized, "Initializable: contract is already initialized");
                  bool isTopLevelCall = !_initializing;
                  if (isTopLevelCall) {
                      _initializing = true;
                      _initialized = true;
                  }
                  _;
                  if (isTopLevelCall) {
                      _initializing = false;
                  }
              }
              /**
               * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
               * {initializer} modifier, directly or indirectly.
               */
              modifier onlyInitializing() {
                  require(_initializing, "Initializable: contract is not initializing");
                  _;
              }
              function _isConstructor() private view returns (bool) {
                  return !AddressUpgradeable.isContract(address(this));
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
          pragma solidity ^0.8.0;
          import "../utils/ContextUpgradeable.sol";
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module which allows children to implement an emergency stop
           * mechanism that can be triggered by an authorized account.
           *
           * This module is used through inheritance. It will make available the
           * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
           * the functions of your contract. Note that they will not be pausable by
           * simply including this module, only once the modifiers are put in place.
           */
          abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
              /**
               * @dev Emitted when the pause is triggered by `account`.
               */
              event Paused(address account);
              /**
               * @dev Emitted when the pause is lifted by `account`.
               */
              event Unpaused(address account);
              bool private _paused;
              /**
               * @dev Initializes the contract in unpaused state.
               */
              function __Pausable_init() internal onlyInitializing {
                  __Context_init_unchained();
                  __Pausable_init_unchained();
              }
              function __Pausable_init_unchained() internal onlyInitializing {
                  _paused = false;
              }
              /**
               * @dev Returns true if the contract is paused, and false otherwise.
               */
              function paused() public view virtual returns (bool) {
                  return _paused;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is not paused.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              modifier whenNotPaused() {
                  require(!paused(), "Pausable: paused");
                  _;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is paused.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              modifier whenPaused() {
                  require(paused(), "Pausable: not paused");
                  _;
              }
              /**
               * @dev Triggers stopped state.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              function _pause() internal virtual whenNotPaused {
                  _paused = true;
                  emit Paused(_msgSender());
              }
              /**
               * @dev Returns to normal state.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              function _unpause() internal virtual whenPaused {
                  _paused = false;
                  emit Unpaused(_msgSender());
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
          pragma solidity ^0.8.0;
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module that helps prevent reentrant calls to a function.
           *
           * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
           * available, which can be applied to functions to make sure there are no nested
           * (reentrant) calls to them.
           *
           * Note that because there is a single `nonReentrant` guard, functions marked as
           * `nonReentrant` may not call one another. This can be worked around by making
           * those functions `private`, and then adding `external` `nonReentrant` entry
           * points to them.
           *
           * TIP: If you would like to learn more about reentrancy and alternative ways
           * to protect against it, check out our blog post
           * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
           */
          abstract contract ReentrancyGuardUpgradeable is Initializable {
              // Booleans are more expensive than uint256 or any type that takes up a full
              // word because each write operation emits an extra SLOAD to first read the
              // slot's contents, replace the bits taken up by the boolean, and then write
              // back. This is the compiler's defense against contract upgrades and
              // pointer aliasing, and it cannot be disabled.
              // The values being non-zero value makes deployment a bit more expensive,
              // but in exchange the refund on every call to nonReentrant will be lower in
              // amount. Since refunds are capped to a percentage of the total
              // transaction's gas, it is best to keep them low in cases like this one, to
              // increase the likelihood of the full refund coming into effect.
              uint256 private constant _NOT_ENTERED = 1;
              uint256 private constant _ENTERED = 2;
              uint256 private _status;
              function __ReentrancyGuard_init() internal onlyInitializing {
                  __ReentrancyGuard_init_unchained();
              }
              function __ReentrancyGuard_init_unchained() internal onlyInitializing {
                  _status = _NOT_ENTERED;
              }
              /**
               * @dev Prevents a contract from calling itself, directly or indirectly.
               * Calling a `nonReentrant` function from another `nonReentrant`
               * function is not supported. It is possible to prevent this from happening
               * by making the `nonReentrant` function external, and making it call a
               * `private` function that does the actual work.
               */
              modifier nonReentrant() {
                  // On the first call to nonReentrant, _notEntered will be true
                  require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                  // Any calls to nonReentrant after this point will fail
                  _status = _ENTERED;
                  _;
                  // By storing the original value once again, a refund is triggered (see
                  // https://eips.ethereum.org/EIPS/eip-2200)
                  _status = _NOT_ENTERED;
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
          pragma solidity ^0.8.0;
          import "../IERC20Upgradeable.sol";
          import "../../../utils/AddressUpgradeable.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 SafeERC20Upgradeable {
              using AddressUpgradeable for address;
              function safeTransfer(
                  IERC20Upgradeable token,
                  address to,
                  uint256 value
              ) internal {
                  _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
              }
              function safeTransferFrom(
                  IERC20Upgradeable 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(
                  IERC20Upgradeable 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'
                  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(
                  IERC20Upgradeable token,
                  address spender,
                  uint256 value
              ) internal {
                  uint256 newAllowance = token.allowance(address(this), spender) + value;
                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
              }
              function safeDecreaseAllowance(
                  IERC20Upgradeable token,
                  address spender,
                  uint256 value
              ) internal {
                  unchecked {
                      uint256 oldAllowance = token.allowance(address(this), spender);
                      require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                      uint256 newAllowance = oldAllowance - value;
                      _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(IERC20Upgradeable 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
                      require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/cryptography/ECDSA.sol)
          pragma solidity ^0.8.0;
          import "../Strings.sol";
          /**
           * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
           *
           * These functions can be used to verify that a message was signed by the holder
           * of the private keys of a given address.
           */
          library ECDSA {
              enum RecoverError {
                  NoError,
                  InvalidSignature,
                  InvalidSignatureLength,
                  InvalidSignatureS,
                  InvalidSignatureV
              }
              function _throwError(RecoverError error) private pure {
                  if (error == RecoverError.NoError) {
                      return; // no error: do nothing
                  } else if (error == RecoverError.InvalidSignature) {
                      revert("ECDSA: invalid signature");
                  } else if (error == RecoverError.InvalidSignatureLength) {
                      revert("ECDSA: invalid signature length");
                  } else if (error == RecoverError.InvalidSignatureS) {
                      revert("ECDSA: invalid signature 's' value");
                  } else if (error == RecoverError.InvalidSignatureV) {
                      revert("ECDSA: invalid signature 'v' value");
                  }
              }
              /**
               * @dev Returns the address that signed a hashed message (`hash`) with
               * `signature` or error string. This address can then be used for verification purposes.
               *
               * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
               * this function rejects them by requiring the `s` value to be in the lower
               * half order, and the `v` value to be either 27 or 28.
               *
               * IMPORTANT: `hash` _must_ be the result of a hash operation for the
               * verification to be secure: it is possible to craft signatures that
               * recover to arbitrary addresses for non-hashed data. A safe way to ensure
               * this is by receiving a hash of the original message (which may otherwise
               * be too long), and then calling {toEthSignedMessageHash} on it.
               *
               * Documentation for signature generation:
               * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
               * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
               *
               * _Available since v4.3._
               */
              function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
                  // Check the signature length
                  // - case 65: r,s,v signature (standard)
                  // - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
                  if (signature.length == 65) {
                      bytes32 r;
                      bytes32 s;
                      uint8 v;
                      // ecrecover takes the signature parameters, and the only way to get them
                      // currently is to use assembly.
                      assembly {
                          r := mload(add(signature, 0x20))
                          s := mload(add(signature, 0x40))
                          v := byte(0, mload(add(signature, 0x60)))
                      }
                      return tryRecover(hash, v, r, s);
                  } else if (signature.length == 64) {
                      bytes32 r;
                      bytes32 vs;
                      // ecrecover takes the signature parameters, and the only way to get them
                      // currently is to use assembly.
                      assembly {
                          r := mload(add(signature, 0x20))
                          vs := mload(add(signature, 0x40))
                      }
                      return tryRecover(hash, r, vs);
                  } else {
                      return (address(0), RecoverError.InvalidSignatureLength);
                  }
              }
              /**
               * @dev Returns the address that signed a hashed message (`hash`) with
               * `signature`. This address can then be used for verification purposes.
               *
               * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
               * this function rejects them by requiring the `s` value to be in the lower
               * half order, and the `v` value to be either 27 or 28.
               *
               * IMPORTANT: `hash` _must_ be the result of a hash operation for the
               * verification to be secure: it is possible to craft signatures that
               * recover to arbitrary addresses for non-hashed data. A safe way to ensure
               * this is by receiving a hash of the original message (which may otherwise
               * be too long), and then calling {toEthSignedMessageHash} on it.
               */
              function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
                  (address recovered, RecoverError error) = tryRecover(hash, signature);
                  _throwError(error);
                  return recovered;
              }
              /**
               * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
               *
               * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
               *
               * _Available since v4.3._
               */
              function tryRecover(
                  bytes32 hash,
                  bytes32 r,
                  bytes32 vs
              ) internal pure returns (address, RecoverError) {
                  bytes32 s;
                  uint8 v;
                  assembly {
                      s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                      v := add(shr(255, vs), 27)
                  }
                  return tryRecover(hash, v, r, s);
              }
              /**
               * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
               *
               * _Available since v4.2._
               */
              function recover(
                  bytes32 hash,
                  bytes32 r,
                  bytes32 vs
              ) internal pure returns (address) {
                  (address recovered, RecoverError error) = tryRecover(hash, r, vs);
                  _throwError(error);
                  return recovered;
              }
              /**
               * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
               * `r` and `s` signature fields separately.
               *
               * _Available since v4.3._
               */
              function tryRecover(
                  bytes32 hash,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) internal pure returns (address, RecoverError) {
                  // 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 (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): 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) {
                      return (address(0), RecoverError.InvalidSignatureS);
                  }
                  if (v != 27 && v != 28) {
                      return (address(0), RecoverError.InvalidSignatureV);
                  }
                  // If the signature is valid (and not malleable), return the signer address
                  address signer = ecrecover(hash, v, r, s);
                  if (signer == address(0)) {
                      return (address(0), RecoverError.InvalidSignature);
                  }
                  return (signer, RecoverError.NoError);
              }
              /**
               * @dev Overload of {ECDSA-recover} that receives the `v`,
               * `r` and `s` signature fields separately.
               */
              function recover(
                  bytes32 hash,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) internal pure returns (address) {
                  (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
                  _throwError(error);
                  return recovered;
              }
              /**
               * @dev Returns an Ethereum Signed Message, created from a `hash`. This
               * produces hash corresponding to the one signed with the
               * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
               * JSON-RPC method as part of EIP-191.
               *
               * See {recover}.
               */
              function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
                  // 32 is the length in bytes of hash,
                  // enforced by the type signature above
                  return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
          32", hash));
              }
              /**
               * @dev Returns an Ethereum Signed Message, created from `s`. This
               * produces hash corresponding to the one signed with the
               * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
               * JSON-RPC method as part of EIP-191.
               *
               * See {recover}.
               */
              function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
                  return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
          ", Strings.toString(s.length), s));
              }
              /**
               * @dev Returns an Ethereum Signed Typed Data, created from a
               * `domainSeparator` and a `structHash`. This produces hash corresponding
               * to the one signed with the
               * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
               * JSON-RPC method as part of EIP-712.
               *
               * See {recover}.
               */
              function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
                  return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash));
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC20 standard as defined in the EIP.
           */
          interface IERC20Upgradeable {
              /**
               * @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
          // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
          pragma solidity ^0.8.0;
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract ContextUpgradeable is Initializable {
              function __Context_init() internal onlyInitializing {
                  __Context_init_unchained();
              }
              function __Context_init_unchained() internal onlyInitializing {
              }
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  return msg.data;
              }
              uint256[50] private __gap;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Address.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Collection of functions related to the address type
           */
          library AddressUpgradeable {
              /**
               * @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;
                  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");
                  (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");
                  (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");
                  (bool success, bytes memory returndata) = target.staticcall(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
               * revert reason using the provided one.
               *
               * _Available since v4.3._
               */
              function verifyCallResult(
                  bool success,
                  bytes memory returndata,
                  string memory errorMessage
              ) internal 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
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev String operations.
           */
          library Strings {
              bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
              /**
               * @dev Converts a `uint256` to its ASCII `string` decimal representation.
               */
              function toString(uint256 value) internal pure returns (string memory) {
                  // Inspired by OraclizeAPI's implementation - MIT licence
                  // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                  if (value == 0) {
                      return "0";
                  }
                  uint256 temp = value;
                  uint256 digits;
                  while (temp != 0) {
                      digits++;
                      temp /= 10;
                  }
                  bytes memory buffer = new bytes(digits);
                  while (value != 0) {
                      digits -= 1;
                      buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                      value /= 10;
                  }
                  return string(buffer);
              }
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
               */
              function toHexString(uint256 value) internal pure returns (string memory) {
                  if (value == 0) {
                      return "0x00";
                  }
                  uint256 temp = value;
                  uint256 length = 0;
                  while (temp != 0) {
                      length++;
                      temp >>= 8;
                  }
                  return toHexString(value, length);
              }
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
               */
              function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                  bytes memory buffer = new bytes(2 * length + 2);
                  buffer[0] = "0";
                  buffer[1] = "x";
                  for (uint256 i = 2 * length + 1; i > 1; --i) {
                      buffer[i] = _HEX_SYMBOLS[value & 0xf];
                      value >>= 4;
                  }
                  require(value == 0, "Strings: hex length insufficient");
                  return string(buffer);
              }
          }
          

          File 4 of 6: ERC721Delegate
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
          import '@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol';
          import '@openzeppelin/contracts/access/AccessControl.sol';
          import './MarketConsts.sol';
          import './IDelegate.sol';
          contract ERC721Delegate is IDelegate, AccessControl, IERC721Receiver {
              bytes32 public constant DELEGATION_CALLER = keccak256('DELEGATION_CALLER');
              struct Pair {
                  IERC721 token;
                  uint256 tokenId;
              }
              constructor() {
                  _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
              }
              function onERC721Received(
                  address,
                  address,
                  uint256,
                  bytes calldata
              ) external override returns (bytes4) {
                  return this.onERC721Received.selector;
              }
              function decode(bytes calldata data) internal pure returns (Pair[] memory) {
                  return abi.decode(data, (Pair[]));
              }
              function delegateType() external view returns (uint256) {
                  // return uint256(Market.DelegationType.ERC721);
                  return 1;
              }
              function executeSell(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external onlyRole(DELEGATION_CALLER) returns (bool) {
                  Pair[] memory pairs = decode(data);
                  for (uint256 i = 0; i < pairs.length; i++) {
                      Pair memory p = pairs[i];
                      p.token.safeTransferFrom(seller, buyer, p.tokenId);
                  }
                  return true;
              }
              function executeBuy(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external onlyRole(DELEGATION_CALLER) returns (bool) {
                  Pair[] memory pairs = decode(data);
                  for (uint256 i = 0; i < pairs.length; i++) {
                      Pair memory p = pairs[i];
                      p.token.safeTransferFrom(seller, buyer, p.tokenId);
                  }
                  return true;
              }
              function executeBid(
                  address seller,
                  address previousBidder,
                  address, // bidder,
                  bytes calldata data
              ) external onlyRole(DELEGATION_CALLER) returns (bool) {
                  if (previousBidder == address(0)) {
                      Pair[] memory pairs = decode(data);
                      for (uint256 i = 0; i < pairs.length; i++) {
                          Pair memory p = pairs[i];
                          p.token.safeTransferFrom(seller, address(this), p.tokenId);
                      }
                  }
                  return true;
              }
              function executeAuctionComplete(
                  address, // seller,
                  address buyer,
                  bytes calldata data
              ) external onlyRole(DELEGATION_CALLER) returns (bool) {
                  Pair[] memory pairs = decode(data);
                  for (uint256 i = 0; i < pairs.length; i++) {
                      Pair memory p = pairs[i];
                      p.token.safeTransferFrom(address(this), buyer, p.tokenId);
                  }
                  return true;
              }
              function executeAuctionRefund(
                  address seller,
                  address, // lastBidder,
                  bytes calldata data
              ) external onlyRole(DELEGATION_CALLER) returns (bool) {
                  Pair[] memory pairs = decode(data);
                  for (uint256 i = 0; i < pairs.length; i++) {
                      Pair memory p = pairs[i];
                      p.token.safeTransferFrom(address(this), seller, p.tokenId);
                  }
                  return true;
              }
              function transferBatch(Pair[] memory pairs, address to) public {
                  for (uint256 i = 0; i < pairs.length; i++) {
                      Pair memory p = pairs[i];
                      p.token.safeTransferFrom(msg.sender, to, p.tokenId);
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)
          pragma solidity ^0.8.0;
          import "../../utils/introspection/IERC165.sol";
          /**
           * @dev Required interface of an ERC721 compliant contract.
           */
          interface IERC721 is IERC165 {
              /**
               * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
               */
              event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
              /**
               * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
               */
              event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
              /**
               * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
               */
              event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
              /**
               * @dev Returns the number of tokens in ``owner``'s account.
               */
              function balanceOf(address owner) external view returns (uint256 balance);
              /**
               * @dev Returns the owner of the `tokenId` token.
               *
               * Requirements:
               *
               * - `tokenId` must exist.
               */
              function ownerOf(uint256 tokenId) external view returns (address owner);
              /**
               * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
               * are aware of the ERC721 protocol to prevent tokens from being forever locked.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must exist and be owned by `from`.
               * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
               * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
               *
               * Emits a {Transfer} event.
               */
              function safeTransferFrom(
                  address from,
                  address to,
                  uint256 tokenId
              ) external;
              /**
               * @dev Transfers `tokenId` token from `from` to `to`.
               *
               * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must be owned by `from`.
               * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
               *
               * Emits a {Transfer} event.
               */
              function transferFrom(
                  address from,
                  address to,
                  uint256 tokenId
              ) external;
              /**
               * @dev Gives permission to `to` to transfer `tokenId` token to another account.
               * The approval is cleared when the token is transferred.
               *
               * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
               *
               * Requirements:
               *
               * - The caller must own the token or be an approved operator.
               * - `tokenId` must exist.
               *
               * Emits an {Approval} event.
               */
              function approve(address to, uint256 tokenId) external;
              /**
               * @dev Returns the account approved for `tokenId` token.
               *
               * Requirements:
               *
               * - `tokenId` must exist.
               */
              function getApproved(uint256 tokenId) external view returns (address operator);
              /**
               * @dev Approve or remove `operator` as an operator for the caller.
               * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
               *
               * Requirements:
               *
               * - The `operator` cannot be the caller.
               *
               * Emits an {ApprovalForAll} event.
               */
              function setApprovalForAll(address operator, bool _approved) external;
              /**
               * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
               *
               * See {setApprovalForAll}
               */
              function isApprovedForAll(address owner, address operator) external view returns (bool);
              /**
               * @dev Safely transfers `tokenId` token from `from` to `to`.
               *
               * Requirements:
               *
               * - `from` cannot be the zero address.
               * - `to` cannot be the zero address.
               * - `tokenId` token must exist and be owned by `from`.
               * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
               * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
               *
               * Emits a {Transfer} event.
               */
              function safeTransferFrom(
                  address from,
                  address to,
                  uint256 tokenId,
                  bytes calldata data
              ) external;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)
          pragma solidity ^0.8.0;
          /**
           * @title ERC721 token receiver interface
           * @dev Interface for any contract that wants to support safeTransfers
           * from ERC721 asset contracts.
           */
          interface IERC721Receiver {
              /**
               * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
               * by `operator` from `from`, this function is called.
               *
               * It must return its Solidity selector to confirm the token transfer.
               * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
               *
               * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
               */
              function onERC721Received(
                  address operator,
                  address from,
                  uint256 tokenId,
                  bytes calldata data
              ) external returns (bytes4);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (access/AccessControl.sol)
          pragma solidity ^0.8.0;
          import "./IAccessControl.sol";
          import "../utils/Context.sol";
          import "../utils/Strings.sol";
          import "../utils/introspection/ERC165.sol";
          /**
           * @dev Contract module that allows children to implement role-based access
           * control mechanisms. This is a lightweight version that doesn't allow enumerating role
           * members except through off-chain means by accessing the contract event logs. Some
           * applications may benefit from on-chain enumerability, for those cases see
           * {AccessControlEnumerable}.
           *
           * Roles are referred to by their `bytes32` identifier. These should be exposed
           * in the external API and be unique. The best way to achieve this is by
           * using `public constant` hash digests:
           *
           * ```
           * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
           * ```
           *
           * Roles can be used to represent a set of permissions. To restrict access to a
           * function call, use {hasRole}:
           *
           * ```
           * function foo() public {
           *     require(hasRole(MY_ROLE, msg.sender));
           *     ...
           * }
           * ```
           *
           * Roles can be granted and revoked dynamically via the {grantRole} and
           * {revokeRole} functions. Each role has an associated admin role, and only
           * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
           *
           * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
           * that only accounts with this role will be able to grant or revoke other
           * roles. More complex role relationships can be created by using
           * {_setRoleAdmin}.
           *
           * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
           * grant and revoke this role. Extra precautions should be taken to secure
           * accounts that have been granted it.
           */
          abstract contract AccessControl is Context, IAccessControl, ERC165 {
              struct RoleData {
                  mapping(address => bool) members;
                  bytes32 adminRole;
              }
              mapping(bytes32 => RoleData) private _roles;
              bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
              /**
               * @dev Modifier that checks that an account has a specific role. Reverts
               * with a standardized message including the required role.
               *
               * The format of the revert reason is given by the following regular expression:
               *
               *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
               *
               * _Available since v4.1._
               */
              modifier onlyRole(bytes32 role) {
                  _checkRole(role, _msgSender());
                  _;
              }
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                  return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
              }
              /**
               * @dev Returns `true` if `account` has been granted `role`.
               */
              function hasRole(bytes32 role, address account) public view override returns (bool) {
                  return _roles[role].members[account];
              }
              /**
               * @dev Revert with a standard message if `account` is missing `role`.
               *
               * The format of the revert reason is given by the following regular expression:
               *
               *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
               */
              function _checkRole(bytes32 role, address account) internal view {
                  if (!hasRole(role, account)) {
                      revert(
                          string(
                              abi.encodePacked(
                                  "AccessControl: account ",
                                  Strings.toHexString(uint160(account), 20),
                                  " is missing role ",
                                  Strings.toHexString(uint256(role), 32)
                              )
                          )
                      );
                  }
              }
              /**
               * @dev Returns the admin role that controls `role`. See {grantRole} and
               * {revokeRole}.
               *
               * To change a role's admin, use {_setRoleAdmin}.
               */
              function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
                  return _roles[role].adminRole;
              }
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                  _grantRole(role, account);
              }
              /**
               * @dev Revokes `role` from `account`.
               *
               * If `account` had been granted `role`, emits a {RoleRevoked} event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                  _revokeRole(role, account);
              }
              /**
               * @dev Revokes `role` from the calling account.
               *
               * Roles are often managed via {grantRole} and {revokeRole}: this function's
               * purpose is to provide a mechanism for accounts to lose their privileges
               * if they are compromised (such as when a trusted device is misplaced).
               *
               * If the calling account had been revoked `role`, emits a {RoleRevoked}
               * event.
               *
               * Requirements:
               *
               * - the caller must be `account`.
               */
              function renounceRole(bytes32 role, address account) public virtual override {
                  require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                  _revokeRole(role, account);
              }
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event. Note that unlike {grantRole}, this function doesn't perform any
               * checks on the calling account.
               *
               * [WARNING]
               * ====
               * This function should only be called from the constructor when setting
               * up the initial roles for the system.
               *
               * Using this function in any other way is effectively circumventing the admin
               * system imposed by {AccessControl}.
               * ====
               *
               * NOTE: This function is deprecated in favor of {_grantRole}.
               */
              function _setupRole(bytes32 role, address account) internal virtual {
                  _grantRole(role, account);
              }
              /**
               * @dev Sets `adminRole` as ``role``'s admin role.
               *
               * Emits a {RoleAdminChanged} event.
               */
              function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                  bytes32 previousAdminRole = getRoleAdmin(role);
                  _roles[role].adminRole = adminRole;
                  emit RoleAdminChanged(role, previousAdminRole, adminRole);
              }
              /**
               * @dev Grants `role` to `account`.
               *
               * Internal function without access restriction.
               */
              function _grantRole(bytes32 role, address account) internal virtual {
                  if (!hasRole(role, account)) {
                      _roles[role].members[account] = true;
                      emit RoleGranted(role, account, _msgSender());
                  }
              }
              /**
               * @dev Revokes `role` from `account`.
               *
               * Internal function without access restriction.
               */
              function _revokeRole(bytes32 role, address account) internal virtual {
                  if (hasRole(role, account)) {
                      _roles[role].members[account] = false;
                      emit RoleRevoked(role, account, _msgSender());
                  }
              }
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import './IDelegate.sol';
          import './IWETHUpgradable.sol';
          library Market {
              uint256 constant INTENT_SELL = 1;
              uint256 constant INTENT_AUCTION = 2;
              uint256 constant INTENT_BUY = 3;
              uint8 constant SIGN_V1 = 1;
              uint8 constant SIGN_V3 = 3;
              struct OrderItem {
                  uint256 price;
                  bytes data;
              }
              struct Order {
                  uint256 salt;
                  address user;
                  uint256 network;
                  uint256 intent;
                  uint256 delegateType;
                  uint256 deadline;
                  IERC20Upgradeable currency;
                  bytes dataMask;
                  OrderItem[] items;
                  // signature
                  bytes32 r;
                  bytes32 s;
                  uint8 v;
                  uint8 signVersion;
              }
              struct Fee {
                  uint256 percentage;
                  address to;
              }
              struct SettleDetail {
                  Market.Op op;
                  uint256 orderIdx;
                  uint256 itemIdx;
                  uint256 price;
                  bytes32 itemHash;
                  IDelegate executionDelegate;
                  bytes dataReplacement;
                  uint256 bidIncentivePct;
                  uint256 aucMinIncrementPct;
                  uint256 aucIncDurationSecs;
                  Fee[] fees;
              }
              struct SettleShared {
                  uint256 salt;
                  uint256 deadline;
                  uint256 amountToEth;
                  uint256 amountToWeth;
                  address user;
                  bool canFail;
              }
              struct RunInput {
                  Order[] orders;
                  SettleDetail[] details;
                  SettleShared shared;
                  // signature
                  bytes32 r;
                  bytes32 s;
                  uint8 v;
              }
              struct OngoingAuction {
                  uint256 price;
                  uint256 netPrice;
                  uint256 endAt;
                  address bidder;
              }
              enum InvStatus {
                  NEW,
                  AUCTION,
                  COMPLETE,
                  CANCELLED,
                  REFUNDED
              }
              enum Op {
                  INVALID,
                  // off-chain
                  COMPLETE_SELL_OFFER,
                  COMPLETE_BUY_OFFER,
                  CANCEL_OFFER,
                  // auction
                  BID,
                  COMPLETE_AUCTION,
                  REFUND_AUCTION,
                  REFUND_AUCTION_STUCK_ITEM
              }
              enum DelegationType {
                  INVALID,
                  ERC721,
                  ERC1155
              }
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          interface IDelegate {
              function delegateType() external view returns (uint256);
              function executeSell(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external returns (bool);
              function executeBuy(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external returns (bool);
              function executeBid(
                  address seller,
                  address previousBidder,
                  address bidder,
                  bytes calldata data
              ) external returns (bool);
              function executeAuctionComplete(
                  address seller,
                  address buyer,
                  bytes calldata data
              ) external returns (bool);
              function executeAuctionRefund(
                  address seller,
                  address lastBidder,
                  bytes calldata data
              ) external returns (bool);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC165 standard, as defined in the
           * https://eips.ethereum.org/EIPS/eip-165[EIP].
           *
           * Implementers can declare support of contract interfaces, which can then be
           * queried by others ({ERC165Checker}).
           *
           * For an implementation, see {ERC165}.
           */
          interface IERC165 {
              /**
               * @dev Returns true if this contract implements the interface defined by
               * `interfaceId`. See the corresponding
               * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
               * to learn more about how these ids are created.
               *
               * This function call must use less than 30 000 gas.
               */
              function supportsInterface(bytes4 interfaceId) external view returns (bool);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev External interface of AccessControl declared to support ERC165 detection.
           */
          interface IAccessControl {
              /**
               * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
               *
               * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
               * {RoleAdminChanged} not being emitted signaling this.
               *
               * _Available since v3.1._
               */
              event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
              /**
               * @dev Emitted when `account` is granted `role`.
               *
               * `sender` is the account that originated the contract call, an admin role
               * bearer except when using {AccessControl-_setupRole}.
               */
              event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
              /**
               * @dev Emitted when `account` is revoked `role`.
               *
               * `sender` is the account that originated the contract call:
               *   - if using `revokeRole`, it is the admin role bearer
               *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
               */
              event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
              /**
               * @dev Returns `true` if `account` has been granted `role`.
               */
              function hasRole(bytes32 role, address account) external view returns (bool);
              /**
               * @dev Returns the admin role that controls `role`. See {grantRole} and
               * {revokeRole}.
               *
               * To change a role's admin, use {AccessControl-_setRoleAdmin}.
               */
              function getRoleAdmin(bytes32 role) external view returns (bytes32);
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function grantRole(bytes32 role, address account) external;
              /**
               * @dev Revokes `role` from `account`.
               *
               * If `account` had been granted `role`, emits a {RoleRevoked} event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function revokeRole(bytes32 role, address account) external;
              /**
               * @dev Revokes `role` from the calling account.
               *
               * Roles are often managed via {grantRole} and {revokeRole}: this function's
               * purpose is to provide a mechanism for accounts to lose their privileges
               * if they are compromised (such as when a trusted device is misplaced).
               *
               * If the calling account had been granted `role`, emits a {RoleRevoked}
               * event.
               *
               * Requirements:
               *
               * - the caller must be `account`.
               */
              function renounceRole(bytes32 role, address account) external;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract Context {
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  return msg.data;
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev String operations.
           */
          library Strings {
              bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
              /**
               * @dev Converts a `uint256` to its ASCII `string` decimal representation.
               */
              function toString(uint256 value) internal pure returns (string memory) {
                  // Inspired by OraclizeAPI's implementation - MIT licence
                  // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                  if (value == 0) {
                      return "0";
                  }
                  uint256 temp = value;
                  uint256 digits;
                  while (temp != 0) {
                      digits++;
                      temp /= 10;
                  }
                  bytes memory buffer = new bytes(digits);
                  while (value != 0) {
                      digits -= 1;
                      buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                      value /= 10;
                  }
                  return string(buffer);
              }
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
               */
              function toHexString(uint256 value) internal pure returns (string memory) {
                  if (value == 0) {
                      return "0x00";
                  }
                  uint256 temp = value;
                  uint256 length = 0;
                  while (temp != 0) {
                      length++;
                      temp >>= 8;
                  }
                  return toHexString(value, length);
              }
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
               */
              function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                  bytes memory buffer = new bytes(2 * length + 2);
                  buffer[0] = "0";
                  buffer[1] = "x";
                  for (uint256 i = 2 * length + 1; i > 1; --i) {
                      buffer[i] = _HEX_SYMBOLS[value & 0xf];
                      value >>= 4;
                  }
                  require(value == 0, "Strings: hex length insufficient");
                  return string(buffer);
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
          pragma solidity ^0.8.0;
          import "./IERC165.sol";
          /**
           * @dev Implementation of the {IERC165} interface.
           *
           * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
           * for the additional interface id that will be supported. For example:
           *
           * ```solidity
           * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
           *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
           * }
           * ```
           *
           * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
           */
          abstract contract ERC165 is IERC165 {
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                  return interfaceId == type(IERC165).interfaceId;
              }
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import '@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol';
          interface IWETHUpgradable is IERC20Upgradeable {
              function deposit() external payable;
              function withdraw(uint256 wad) external;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC20 standard as defined in the EIP.
           */
          interface IERC20Upgradeable {
              /**
               * @dev Returns the amount of tokens in existence.
               */
              function totalSupply() external view returns (uint256);
              /**
               * @dev Returns the amount of tokens owned by `account`.
               */
              function balanceOf(address account) external view returns (uint256);
              /**
               * @dev Moves `amount` tokens from the caller's account to `recipient`.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * Emits a {Transfer} event.
               */
              function transfer(address recipient, uint256 amount) external returns (bool);
              /**
               * @dev Returns the remaining number of tokens that `spender` will be
               * allowed to spend on behalf of `owner` through {transferFrom}. This is
               * zero by default.
               *
               * This value changes when {approve} or {transferFrom} are called.
               */
              function allowance(address owner, address spender) external view returns (uint256);
              /**
               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * IMPORTANT: Beware that changing an allowance with this method brings the risk
               * that someone may use both the old and the new allowance by unfortunate
               * transaction ordering. One possible solution to mitigate this race
               * condition is to first reduce the spender's allowance to 0 and set the
               * desired value afterwards:
               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
               *
               * Emits an {Approval} event.
               */
              function approve(address spender, uint256 amount) external returns (bool);
              /**
               * @dev Moves `amount` tokens from `sender` to `recipient` using the
               * allowance mechanism. `amount` is then deducted from the caller's
               * allowance.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * Emits a {Transfer} event.
               */
              function transferFrom(
                  address sender,
                  address recipient,
                  uint256 amount
              ) external returns (bool);
              /**
               * @dev Emitted when `value` tokens are moved from one account (`from`) to
               * another (`to`).
               *
               * Note that `value` may be zero.
               */
              event Transfer(address indexed from, address indexed to, uint256 value);
              /**
               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
               * a call to {approve}. `value` is the new allowance.
               */
              event Approval(address indexed owner, address indexed spender, uint256 value);
          }
          

          File 5 of 6: WyvernProxyRegistry
          pragma solidity ^0.4.13;
          
          contract Ownable {
            address public owner;
          
          
            event OwnershipRenounced(address indexed previousOwner);
            event OwnershipTransferred(
              address indexed previousOwner,
              address indexed newOwner
            );
          
          
            /**
             * @dev The Ownable constructor sets the original `owner` of the contract to the sender
             * account.
             */
            constructor() public {
              owner = msg.sender;
            }
          
            /**
             * @dev Throws if called by any account other than the owner.
             */
            modifier onlyOwner() {
              require(msg.sender == owner);
              _;
            }
          
            /**
             * @dev Allows the current owner to transfer control of the contract to a newOwner.
             * @param newOwner The address to transfer ownership to.
             */
            function transferOwnership(address newOwner) public onlyOwner {
              require(newOwner != address(0));
              emit OwnershipTransferred(owner, newOwner);
              owner = newOwner;
            }
          
            /**
             * @dev Allows the current owner to relinquish control of the contract.
             */
            function renounceOwnership() public onlyOwner {
              emit OwnershipRenounced(owner);
              owner = address(0);
            }
          }
          
          contract ERC20Basic {
            function totalSupply() public view returns (uint256);
            function balanceOf(address who) public view returns (uint256);
            function transfer(address to, uint256 value) public returns (bool);
            event Transfer(address indexed from, address indexed to, uint256 value);
          }
          
          contract ERC20 is ERC20Basic {
            function allowance(address owner, address spender)
              public view returns (uint256);
          
            function transferFrom(address from, address to, uint256 value)
              public returns (bool);
          
            function approve(address spender, uint256 value) public returns (bool);
            event Approval(
              address indexed owner,
              address indexed spender,
              uint256 value
            );
          }
          
          contract TokenRecipient {
              event ReceivedEther(address indexed sender, uint amount);
              event ReceivedTokens(address indexed from, uint256 value, address indexed token, bytes extraData);
          
              /**
               * @dev Receive tokens and generate a log event
               * @param from Address from which to transfer tokens
               * @param value Amount of tokens to transfer
               * @param token Address of token
               * @param extraData Additional data to log
               */
              function receiveApproval(address from, uint256 value, address token, bytes extraData) public {
                  ERC20 t = ERC20(token);
                  require(t.transferFrom(from, this, value));
                  emit ReceivedTokens(from, value, token, extraData);
              }
          
              /**
               * @dev Receive Ether and generate a log event
               */
              function () payable public {
                  emit ReceivedEther(msg.sender, msg.value);
              }
          }
          
          contract ProxyRegistry is Ownable {
          
              /* DelegateProxy implementation contract. Must be initialized. */
              address public delegateProxyImplementation;
          
              /* Authenticated proxies by user. */
              mapping(address => OwnableDelegateProxy) public proxies;
          
              /* Contracts pending access. */
              mapping(address => uint) public pending;
          
              /* Contracts allowed to call those proxies. */
              mapping(address => bool) public contracts;
          
              /* Delay period for adding an authenticated contract.
                 This mitigates a particular class of potential attack on the Wyvern DAO (which owns this registry) - if at any point the value of assets held by proxy contracts exceeded the value of half the WYV supply (votes in the DAO),
                 a malicious but rational attacker could buy half the Wyvern and grant themselves access to all the proxy contracts. A delay period renders this attack nonthreatening - given two weeks, if that happened, users would have
                 plenty of time to notice and transfer their assets.
              */
              uint public DELAY_PERIOD = 2 weeks;
          
              /**
               * Start the process to enable access for specified contract. Subject to delay period.
               *
               * @dev ProxyRegistry owner only
               * @param addr Address to which to grant permissions
               */
              function startGrantAuthentication (address addr)
                  public
                  onlyOwner
              {
                  require(!contracts[addr] && pending[addr] == 0);
                  pending[addr] = now;
              }
          
              /**
               * End the process to nable access for specified contract after delay period has passed.
               *
               * @dev ProxyRegistry owner only
               * @param addr Address to which to grant permissions
               */
              function endGrantAuthentication (address addr)
                  public
                  onlyOwner
              {
                  require(!contracts[addr] && pending[addr] != 0 && ((pending[addr] + DELAY_PERIOD) < now));
                  pending[addr] = 0;
                  contracts[addr] = true;
              }
          
              /**
               * Revoke access for specified contract. Can be done instantly.
               *
               * @dev ProxyRegistry owner only
               * @param addr Address of which to revoke permissions
               */    
              function revokeAuthentication (address addr)
                  public
                  onlyOwner
              {
                  contracts[addr] = false;
              }
          
              /**
               * Register a proxy contract with this registry
               *
               * @dev Must be called by the user which the proxy is for, creates a new AuthenticatedProxy
               * @return New AuthenticatedProxy contract
               */
              function registerProxy()
                  public
                  returns (OwnableDelegateProxy proxy)
              {
                  require(proxies[msg.sender] == address(0));
                  proxy = new OwnableDelegateProxy(msg.sender, delegateProxyImplementation, abi.encodeWithSignature("initialize(address,address)", msg.sender, address(this)));
                  proxies[msg.sender] = proxy;
                  return proxy;
              }
          
          }
          
          contract WyvernProxyRegistry is ProxyRegistry {
          
              string public constant name = "Project Wyvern Proxy Registry";
          
              /* Whether the initial auth address has been set. */
              bool public initialAddressSet = false;
          
              constructor ()
                  public
              {
                  delegateProxyImplementation = new AuthenticatedProxy();
              }
          
              /** 
               * Grant authentication to the initial Exchange protocol contract
               *
               * @dev No delay, can only be called once - after that the standard registry process with a delay must be used
               * @param authAddress Address of the contract to grant authentication
               */
              function grantInitialAuthentication (address authAddress)
                  onlyOwner
                  public
              {
                  require(!initialAddressSet);
                  initialAddressSet = true;
                  contracts[authAddress] = true;
              }
          
          }
          
          contract OwnedUpgradeabilityStorage {
          
            // Current implementation
            address internal _implementation;
          
            // Owner of the contract
            address private _upgradeabilityOwner;
          
            /**
             * @dev Tells the address of the owner
             * @return the address of the owner
             */
            function upgradeabilityOwner() public view returns (address) {
              return _upgradeabilityOwner;
            }
          
            /**
             * @dev Sets the address of the owner
             */
            function setUpgradeabilityOwner(address newUpgradeabilityOwner) internal {
              _upgradeabilityOwner = newUpgradeabilityOwner;
            }
          
            /**
            * @dev Tells the address of the current implementation
            * @return address of the current implementation
            */
            function implementation() public view returns (address) {
              return _implementation;
            }
          
            /**
            * @dev Tells the proxy type (EIP 897)
            * @return Proxy type, 2 for forwarding proxy
            */
            function proxyType() public pure returns (uint256 proxyTypeId) {
              return 2;
            }
          }
          
          contract AuthenticatedProxy is TokenRecipient, OwnedUpgradeabilityStorage {
          
              /* Whether initialized. */
              bool initialized = false;
          
              /* Address which owns this proxy. */
              address public user;
          
              /* Associated registry with contract authentication information. */
              ProxyRegistry public registry;
          
              /* Whether access has been revoked. */
              bool public revoked;
          
              /* Delegate call could be used to atomically transfer multiple assets owned by the proxy contract with one order. */
              enum HowToCall { Call, DelegateCall }
          
              /* Event fired when the proxy access is revoked or unrevoked. */
              event Revoked(bool revoked);
          
              /**
               * Initialize an AuthenticatedProxy
               *
               * @param addrUser Address of user on whose behalf this proxy will act
               * @param addrRegistry Address of ProxyRegistry contract which will manage this proxy
               */
              function initialize (address addrUser, ProxyRegistry addrRegistry)
                  public
              {
                  require(!initialized);
                  initialized = true;
                  user = addrUser;
                  registry = addrRegistry;
              }
          
              /**
               * Set the revoked flag (allows a user to revoke ProxyRegistry access)
               *
               * @dev Can be called by the user only
               * @param revoke Whether or not to revoke access
               */
              function setRevoke(bool revoke)
                  public
              {
                  require(msg.sender == user);
                  revoked = revoke;
                  emit Revoked(revoke);
              }
          
              /**
               * Execute a message call from the proxy contract
               *
               * @dev Can be called by the user, or by a contract authorized by the registry as long as the user has not revoked access
               * @param dest Address to which the call will be sent
               * @param howToCall Which kind of call to make
               * @param calldata Calldata to send
               * @return Result of the call (success or failure)
               */
              function proxy(address dest, HowToCall howToCall, bytes calldata)
                  public
                  returns (bool result)
              {
                  require(msg.sender == user || (!revoked && registry.contracts(msg.sender)));
                  if (howToCall == HowToCall.Call) {
                      result = dest.call(calldata);
                  } else if (howToCall == HowToCall.DelegateCall) {
                      result = dest.delegatecall(calldata);
                  }
                  return result;
              }
          
              /**
               * Execute a message call and assert success
               * 
               * @dev Same functionality as `proxy`, just asserts the return value
               * @param dest Address to which the call will be sent
               * @param howToCall What kind of call to make
               * @param calldata Calldata to send
               */
              function proxyAssert(address dest, HowToCall howToCall, bytes calldata)
                  public
              {
                  require(proxy(dest, howToCall, calldata));
              }
          
          }
          
          contract Proxy {
          
            /**
            * @dev Tells the address of the implementation where every call will be delegated.
            * @return address of the implementation to which it will be delegated
            */
            function implementation() public view returns (address);
          
            /**
            * @dev Tells the type of proxy (EIP 897)
            * @return Type of proxy, 2 for upgradeable proxy
            */
            function proxyType() public pure returns (uint256 proxyTypeId);
          
            /**
            * @dev Fallback function allowing to perform a delegatecall to the given implementation.
            * This function will return whatever the implementation call returns
            */
            function () payable public {
              address _impl = implementation();
              require(_impl != address(0));
          
              assembly {
                let ptr := mload(0x40)
                calldatacopy(ptr, 0, calldatasize)
                let result := delegatecall(gas, _impl, ptr, calldatasize, 0, 0)
                let size := returndatasize
                returndatacopy(ptr, 0, size)
          
                switch result
                case 0 { revert(ptr, size) }
                default { return(ptr, size) }
              }
            }
          }
          
          contract OwnedUpgradeabilityProxy is Proxy, OwnedUpgradeabilityStorage {
            /**
            * @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 ProxyOwnershipTransferred(address previousOwner, address newOwner);
          
            /**
            * @dev This event will be emitted every time the implementation gets upgraded
            * @param implementation representing the address of the upgraded implementation
            */
            event Upgraded(address indexed implementation);
          
            /**
            * @dev Upgrades the implementation address
            * @param implementation representing the address of the new implementation to be set
            */
            function _upgradeTo(address implementation) internal {
              require(_implementation != implementation);
              _implementation = implementation;
              emit Upgraded(implementation);
            }
          
            /**
            * @dev Throws if called by any account other than the owner.
            */
            modifier onlyProxyOwner() {
              require(msg.sender == proxyOwner());
              _;
            }
          
            /**
             * @dev Tells the address of the proxy owner
             * @return the address of the proxy owner
             */
            function proxyOwner() public view returns (address) {
              return upgradeabilityOwner();
            }
          
            /**
             * @dev Allows the current owner to transfer control of the contract to a newOwner.
             * @param newOwner The address to transfer ownership to.
             */
            function transferProxyOwnership(address newOwner) public onlyProxyOwner {
              require(newOwner != address(0));
              emit ProxyOwnershipTransferred(proxyOwner(), newOwner);
              setUpgradeabilityOwner(newOwner);
            }
          
            /**
             * @dev Allows the upgradeability owner to upgrade the current implementation of the proxy.
             * @param implementation representing the address of the new implementation to be set.
             */
            function upgradeTo(address implementation) public onlyProxyOwner {
              _upgradeTo(implementation);
            }
          
            /**
             * @dev Allows the upgradeability owner to upgrade the current implementation of the proxy
             * and delegatecall the new implementation for initialization.
             * @param implementation representing the address of the new implementation to be set.
             * @param data represents the msg.data to bet sent in the low level call. This parameter may include the function
             * signature of the implementation to be called with the needed payload
             */
            function upgradeToAndCall(address implementation, bytes data) payable public onlyProxyOwner {
              upgradeTo(implementation);
              require(address(this).delegatecall(data));
            }
          }
          
          contract OwnableDelegateProxy is OwnedUpgradeabilityProxy {
          
              constructor(address owner, address initialImplementation, bytes calldata)
                  public
              {
                  setUpgradeabilityOwner(owner);
                  _upgradeTo(initialImplementation);
                  require(initialImplementation.delegatecall(calldata));
              }
          
          }

          File 6 of 6: FeeManagement
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import './TokenSplitter.sol';
          import './FeeSharingSetter.sol';
          import './IWETH.sol';
          import '@openzeppelin/contracts/access/AccessControl.sol';
          import '@openzeppelin/contracts/access/Ownable.sol';
          import '@openzeppelin/contracts/security/Pausable.sol';
          import '@openzeppelin/contracts/security/ReentrancyGuard.sol';
          import '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
          import '@openzeppelin/contracts/utils/Address.sol';
          contract FeeManagement is AccessControl, Pausable, ReentrancyGuard {
              using SafeERC20 for IERC20;
              using SafeERC20 for IWETH;
              bytes32 public constant OPERATOR_ROLE = keccak256('OPERATOR_ROLE');
              TokenSplitter public immutable tokenSplitter;
              FeeSharingSetter public immutable feeSetter;
              IWETH public immutable weth;
              constructor(
                  TokenSplitter tokenSplitter_,
                  FeeSharingSetter feeSetter_,
                  IWETH weth_,
                  address operator_,
                  address admin_
              ) {
                  tokenSplitter = tokenSplitter_;
                  feeSetter = feeSetter_;
                  weth = weth_;
                  if (admin_ == address(0)) {
                      admin_ = msg.sender;
                  }
                  _grantRole(DEFAULT_ADMIN_ROLE, admin_);
                  _grantRole(OPERATOR_ROLE, admin_);
                  if (operator_ != address(0)) {
                      _grantRole(OPERATOR_ROLE, operator_);
                  }
              }
              receive() external payable {}
              function pause() external onlyRole(DEFAULT_ADMIN_ROLE) {
                  _pause();
              }
              function unpause() external onlyRole(DEFAULT_ADMIN_ROLE) {
                  _unpause();
              }
              // withdraw tokens
              function withdraw(address to, IERC20[] calldata tokens)
                  external
                  nonReentrant
                  whenNotPaused
                  onlyRole(DEFAULT_ADMIN_ROLE)
              {
                  require(to != address(0), 'Withdraw: address(0) cannot be recipient');
                  for (uint256 i = 0; i < tokens.length; i++) {
                      IERC20 currency = tokens[i];
                      if (address(currency) == address(0)) {
                          uint256 balance = address(this).balance;
                          if (balance > 0) {
                              Address.sendValue(payable(to), balance);
                          }
                      } else {
                          uint256 balance = currency.balanceOf(address(this));
                          if (balance > 0) {
                              currency.safeTransfer(to, balance);
                          }
                      }
                  }
              }
              function canRelease() external view returns (bool) {
                  return
                      block.number >
                      feeSetter.rewardDurationInBlocks() + feeSetter.lastRewardDistributionBlock();
              }
              function releaseAndUpdateReward(IERC20[] memory tokens, address[] memory accounts)
                  external
                  nonReentrant
                  whenNotPaused
                  onlyRole(OPERATOR_ROLE)
              {
                  _release(tokens);
                  // release x2y2 to pools, skipped when the balance is less than 1 token (the release can be called by anyone)
                  if (tokenSplitter.x2y2Token().balanceOf(address(tokenSplitter)) >= 1 ether) {
                      for (uint256 i = 0; i < accounts.length; i++) {
                          tokenSplitter.releaseTokens(accounts[i]);
                      }
                  }
                  feeSetter.updateRewards();
              }
              function release(IERC20[] memory tokens)
                  external
                  nonReentrant
                  whenNotPaused
                  onlyRole(OPERATOR_ROLE)
              {
                  _release(tokens);
              }
              function _release(IERC20[] memory tokens) internal {
                  uint256 balance = address(this).balance;
                  if (balance > 0) {
                      weth.deposit{value: balance}();
                  }
                  balance = weth.balanceOf(address(this));
                  if (balance > 0) {
                      weth.safeTransfer(address(feeSetter), balance);
                  }
                  for (uint256 i = 0; i < tokens.length; i++) {
                      IERC20 currency = tokens[i];
                      balance = currency.balanceOf(address(this));
                      if (balance > 0) {
                          currency.safeTransfer(address(feeSetter), balance);
                      }
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import {Ownable} from '@openzeppelin/contracts/access/Ownable.sol';
          import {ReentrancyGuard} from '@openzeppelin/contracts/security/ReentrancyGuard.sol';
          import {IERC20, SafeERC20} from '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
          /**
           * @title TokenSplitter
           * @notice It splits X2Y2 to team/treasury/trading volume reward accounts based on shares.
           */
          contract TokenSplitter is Ownable, ReentrancyGuard {
              using SafeERC20 for IERC20;
              struct AccountInfo {
                  uint256 shares;
                  uint256 tokensDistributedToAccount;
              }
              uint256 public immutable TOTAL_SHARES;
              IERC20 public immutable x2y2Token;
              // Total tokens distributed across all accounts
              uint256 public totalTokensDistributed;
              mapping(address => AccountInfo) public accountInfo;
              event NewSharesOwner(address indexed oldRecipient, address indexed newRecipient);
              event TokensTransferred(address indexed account, uint256 amount);
              /**
               * @notice Constructor
               * @param _accounts array of accounts addresses
               * @param _shares array of shares per account
               * @param _x2y2Token address of the X2Y2 token
               */
              constructor(
                  address[] memory _accounts,
                  uint256[] memory _shares,
                  address _x2y2Token
              ) {
                  require(_accounts.length == _shares.length, 'Splitter: Length differ');
                  require(_accounts.length > 0, 'Splitter: Length must be > 0');
                  uint256 currentShares;
                  for (uint256 i = 0; i < _accounts.length; i++) {
                      require(_shares[i] > 0, 'Splitter: Shares are 0');
                      currentShares += _shares[i];
                      accountInfo[_accounts[i]].shares = _shares[i];
                  }
                  TOTAL_SHARES = currentShares;
                  x2y2Token = IERC20(_x2y2Token);
              }
              /**
               * @notice Release X2Y2 tokens to the account
               * @param account address of the account
               */
              function releaseTokens(address account) external nonReentrant {
                  require(accountInfo[account].shares > 0, 'Splitter: Account has no share');
                  // Calculate amount to transfer to the account
                  uint256 totalTokensReceived = x2y2Token.balanceOf(address(this)) + totalTokensDistributed;
                  uint256 pendingRewards = ((totalTokensReceived * accountInfo[account].shares) /
                      TOTAL_SHARES) - accountInfo[account].tokensDistributedToAccount;
                  // Revert if equal to 0
                  require(pendingRewards != 0, 'Splitter: Nothing to transfer');
                  accountInfo[account].tokensDistributedToAccount += pendingRewards;
                  totalTokensDistributed += pendingRewards;
                  // Transfer funds to account
                  x2y2Token.safeTransfer(account, pendingRewards);
                  emit TokensTransferred(account, pendingRewards);
              }
              /**
               * @notice Update share recipient
               * @param _newRecipient address of the new recipient
               * @param _currentRecipient address of the current recipient
               */
              function updateSharesOwner(address _newRecipient, address _currentRecipient)
                  external
                  onlyOwner
              {
                  require(
                      accountInfo[_currentRecipient].shares > 0,
                      'Owner: Current recipient has no shares'
                  );
                  require(accountInfo[_newRecipient].shares == 0, 'Owner: New recipient has existing shares');
                  // Copy shares to new recipient
                  accountInfo[_newRecipient].shares = accountInfo[_currentRecipient].shares;
                  accountInfo[_newRecipient].tokensDistributedToAccount = accountInfo[_currentRecipient]
                      .tokensDistributedToAccount;
                  // Reset existing shares
                  accountInfo[_currentRecipient].shares = 0;
                  accountInfo[_currentRecipient].tokensDistributedToAccount = 0;
                  emit NewSharesOwner(_currentRecipient, _newRecipient);
              }
              /**
               * @notice Retrieve amount of X2Y2 tokens that can be transferred
               * @param account address of the account
               */
              function calculatePendingRewards(address account) external view returns (uint256) {
                  if (accountInfo[account].shares == 0) {
                      return 0;
                  }
                  uint256 totalTokensReceived = x2y2Token.balanceOf(address(this)) + totalTokensDistributed;
                  uint256 pendingRewards = ((totalTokensReceived * accountInfo[account].shares) /
                      TOTAL_SHARES) - accountInfo[account].tokensDistributedToAccount;
                  return pendingRewards;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import {AccessControl} from '@openzeppelin/contracts/access/AccessControl.sol';
          import {ReentrancyGuard} from '@openzeppelin/contracts/security/ReentrancyGuard.sol';
          import {IERC20, SafeERC20} from '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
          import {EnumerableSet} from '@openzeppelin/contracts/utils/structs/EnumerableSet.sol';
          import {FeeSharingSystem} from './FeeSharingSystem.sol';
          import {TokenDistributor} from './TokenDistributor.sol';
          import {IRewardConvertor} from './IRewardConvertor.sol';
          import {IMintableERC20} from './IMintableERC20.sol';
          import {ITokenStaked} from './ITokenStaked.sol';
          /**
           * @title FeeSharingSetter
           * @notice It receives exchange fees and owns the FeeSharingSystem contract.
           * It can plug to AMMs for converting all received currencies to WETH.
           */
          contract FeeSharingSetter is ReentrancyGuard, AccessControl {
              using EnumerableSet for EnumerableSet.AddressSet;
              using SafeERC20 for IERC20;
              // Operator role
              bytes32 public constant OPERATOR_ROLE = keccak256('OPERATOR_ROLE');
              // Min duration for each fee-sharing period (in blocks)
              uint256 public immutable MIN_REWARD_DURATION_IN_BLOCKS;
              // Max duration for each fee-sharing period (in blocks)
              uint256 public immutable MAX_REWARD_DURATION_IN_BLOCKS;
              IERC20 public immutable x2y2Token;
              IERC20 public immutable rewardToken;
              FeeSharingSystem public feeSharingSystem;
              TokenDistributor public immutable tokenDistributor;
              // Reward convertor (tool to convert other currencies to rewardToken)
              IRewardConvertor public rewardConvertor;
              // Last reward block of distribution
              uint256 public lastRewardDistributionBlock;
              // Next reward duration in blocks
              uint256 public nextRewardDurationInBlocks;
              // Reward duration in blocks
              uint256 public rewardDurationInBlocks;
              // Set of addresses that are staking only the fee sharing
              EnumerableSet.AddressSet private _feeStakingAddresses;
              mapping(address => bool) public feeStakingAddressIStaked;
              event ConversionToRewardToken(
                  address indexed token,
                  uint256 amountConverted,
                  uint256 amountReceived
              );
              event FeeStakingAddressesAdded(address[] feeStakingAddresses);
              event FeeStakingAddressesRemoved(address[] feeStakingAddresses);
              event NewRewardDurationInBlocks(uint256 rewardDurationInBlocks);
              event NewRewardConvertor(address rewardConvertor);
              /**
               * @notice Constructor
               * @param _feeSharingSystem address of the fee sharing system
               * @param _minRewardDurationInBlocks minimum reward duration in blocks
               * @param _maxRewardDurationInBlocks maximum reward duration in blocks
               * @param _rewardDurationInBlocks reward duration between two updates in blocks
               */
              constructor(
                  address _feeSharingSystem,
                  uint256 _minRewardDurationInBlocks,
                  uint256 _maxRewardDurationInBlocks,
                  uint256 _rewardDurationInBlocks
              ) {
                  require(
                      (_rewardDurationInBlocks <= _maxRewardDurationInBlocks) &&
                          (_rewardDurationInBlocks >= _minRewardDurationInBlocks),
                      'Owner: Reward duration in blocks outside of range'
                  );
                  MIN_REWARD_DURATION_IN_BLOCKS = _minRewardDurationInBlocks;
                  MAX_REWARD_DURATION_IN_BLOCKS = _maxRewardDurationInBlocks;
                  feeSharingSystem = FeeSharingSystem(_feeSharingSystem);
                  rewardToken = feeSharingSystem.rewardToken();
                  x2y2Token = feeSharingSystem.x2y2Token();
                  tokenDistributor = feeSharingSystem.tokenDistributor();
                  rewardDurationInBlocks = _rewardDurationInBlocks;
                  nextRewardDurationInBlocks = _rewardDurationInBlocks;
                  _setupRole(DEFAULT_ADMIN_ROLE, msg.sender);
              }
              /**
               * @notice Update the reward per block (in rewardToken)
               * @dev It automatically retrieves the number of pending WETH and adjusts
               * based on the balance of X2Y2 in fee-staking addresses that exist in the set.
               */
              function updateRewards() external onlyRole(OPERATOR_ROLE) {
                  if (lastRewardDistributionBlock > 0) {
                      require(
                          block.number > (rewardDurationInBlocks + lastRewardDistributionBlock),
                          'Reward: Too early to add'
                      );
                  }
                  // Adjust for this period
                  if (rewardDurationInBlocks != nextRewardDurationInBlocks) {
                      rewardDurationInBlocks = nextRewardDurationInBlocks;
                  }
                  lastRewardDistributionBlock = block.number;
                  // Calculate the reward to distribute as the balance held by this address
                  uint256 reward = rewardToken.balanceOf(address(this));
                  require(reward != 0, 'Reward: Nothing to distribute');
                  // Check if there is any address eligible for fee-sharing only
                  uint256 numberAddressesForFeeStaking = _feeStakingAddresses.length();
                  // If there are eligible addresses for fee-sharing only, calculate their shares
                  if (numberAddressesForFeeStaking > 0) {
                      uint256[] memory x2y2Balances = new uint256[](numberAddressesForFeeStaking);
                      (uint256 totalAmountStaked, ) = tokenDistributor.userInfo(address(feeSharingSystem));
                      for (uint256 i = 0; i < numberAddressesForFeeStaking; i++) {
                          address a = _feeStakingAddresses.at(i);
                          uint256 balance = x2y2Token.balanceOf(a);
                          if (feeStakingAddressIStaked[a]) {
                              balance = ITokenStaked(a).getTotalStaked();
                          }
                          totalAmountStaked += balance;
                          x2y2Balances[i] = balance;
                      }
                      // Only apply the logic if the totalAmountStaked > 0 (to prevent division by 0)
                      if (totalAmountStaked > 0) {
                          uint256 adjustedReward = reward;
                          for (uint256 i = 0; i < numberAddressesForFeeStaking; i++) {
                              uint256 amountToTransfer = (x2y2Balances[i] * reward) / totalAmountStaked;
                              if (amountToTransfer > 0) {
                                  adjustedReward -= amountToTransfer;
                                  rewardToken.safeTransfer(_feeStakingAddresses.at(i), amountToTransfer);
                              }
                          }
                          // Adjust reward accordingly
                          reward = adjustedReward;
                      }
                  }
                  // Transfer tokens to fee sharing system
                  rewardToken.safeTransfer(address(feeSharingSystem), reward);
                  // Update rewards
                  feeSharingSystem.updateRewards(reward, rewardDurationInBlocks);
              }
              /**
               * @notice Convert currencies to reward token
               * @dev Function only usable only for whitelisted currencies (where no potential side effect)
               * @param token address of the token to sell
               * @param additionalData additional data (e.g., slippage)
               */
              function convertCurrencyToRewardToken(address token, bytes calldata additionalData)
                  external
                  nonReentrant
                  onlyRole(OPERATOR_ROLE)
              {
                  require(address(rewardConvertor) != address(0), 'Convert: RewardConvertor not set');
                  require(token != address(rewardToken), 'Convert: Cannot be reward token');
                  uint256 amountToConvert = IERC20(token).balanceOf(address(this));
                  require(amountToConvert != 0, 'Convert: Amount to convert must be > 0');
                  // Adjust allowance for this transaction only
                  IERC20(token).safeIncreaseAllowance(address(rewardConvertor), amountToConvert);
                  // Exchange token to reward token
                  uint256 amountReceived = rewardConvertor.convert(
                      token,
                      address(rewardToken),
                      amountToConvert,
                      additionalData
                  );
                  emit ConversionToRewardToken(token, amountToConvert, amountReceived);
              }
              /**
               * @notice Add staking addresses
               * @param _stakingAddresses array of addresses eligible for fee-sharing only
               */
              function addFeeStakingAddresses(
                  address[] calldata _stakingAddresses,
                  bool[] calldata _addressIStaked
              ) external onlyRole(DEFAULT_ADMIN_ROLE) {
                  require(_stakingAddresses.length == _addressIStaked.length, 'Owner: param length error');
                  for (uint256 i = 0; i < _stakingAddresses.length; i++) {
                      require(
                          !_feeStakingAddresses.contains(_stakingAddresses[i]),
                          'Owner: Address already registered'
                      );
                      _feeStakingAddresses.add(_stakingAddresses[i]);
                      if (_addressIStaked[i]) {
                          feeStakingAddressIStaked[_stakingAddresses[i]] = true;
                      }
                  }
                  emit FeeStakingAddressesAdded(_stakingAddresses);
              }
              /**
               * @notice Remove staking addresses
               * @param _stakingAddresses array of addresses eligible for fee-sharing only
               */
              function removeFeeStakingAddresses(address[] calldata _stakingAddresses)
                  external
                  onlyRole(DEFAULT_ADMIN_ROLE)
              {
                  for (uint256 i = 0; i < _stakingAddresses.length; i++) {
                      require(
                          _feeStakingAddresses.contains(_stakingAddresses[i]),
                          'Owner: Address not registered'
                      );
                      _feeStakingAddresses.remove(_stakingAddresses[i]);
                      if (feeStakingAddressIStaked[_stakingAddresses[i]]) {
                          delete feeStakingAddressIStaked[_stakingAddresses[i]];
                      }
                  }
                  emit FeeStakingAddressesRemoved(_stakingAddresses);
              }
              /**
               * @notice Set new reward duration in blocks for next update
               * @param _newRewardDurationInBlocks number of blocks for new reward period
               */
              function setNewRewardDurationInBlocks(uint256 _newRewardDurationInBlocks)
                  external
                  onlyRole(DEFAULT_ADMIN_ROLE)
              {
                  require(
                      (_newRewardDurationInBlocks <= MAX_REWARD_DURATION_IN_BLOCKS) &&
                          (_newRewardDurationInBlocks >= MIN_REWARD_DURATION_IN_BLOCKS),
                      'Owner: New reward duration in blocks outside of range'
                  );
                  nextRewardDurationInBlocks = _newRewardDurationInBlocks;
                  emit NewRewardDurationInBlocks(_newRewardDurationInBlocks);
              }
              /**
               * @notice Set reward convertor contract
               * @param _rewardConvertor address of the reward convertor (set to null to deactivate)
               */
              function setRewardConvertor(address _rewardConvertor) external onlyRole(DEFAULT_ADMIN_ROLE) {
                  rewardConvertor = IRewardConvertor(_rewardConvertor);
                  emit NewRewardConvertor(_rewardConvertor);
              }
              /**
               * @notice See addresses eligible for fee-staking
               */
              function viewFeeStakingAddresses() external view returns (address[] memory) {
                  uint256 length = _feeStakingAddresses.length();
                  address[] memory feeStakingAddresses = new address[](length);
                  for (uint256 i = 0; i < length; i++) {
                      feeStakingAddresses[i] = _feeStakingAddresses.at(i);
                  }
                  return (feeStakingAddresses);
              }
          }
          // SPDX-License-Identifier: Unlicensed
          pragma solidity ^0.8.0;
          pragma abicoder v2;
          import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
          interface IWETH is IERC20 {
              function deposit() external payable;
              function withdraw(uint256 wad) external;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (access/AccessControl.sol)
          pragma solidity ^0.8.0;
          import "./IAccessControl.sol";
          import "../utils/Context.sol";
          import "../utils/Strings.sol";
          import "../utils/introspection/ERC165.sol";
          /**
           * @dev Contract module that allows children to implement role-based access
           * control mechanisms. This is a lightweight version that doesn't allow enumerating role
           * members except through off-chain means by accessing the contract event logs. Some
           * applications may benefit from on-chain enumerability, for those cases see
           * {AccessControlEnumerable}.
           *
           * Roles are referred to by their `bytes32` identifier. These should be exposed
           * in the external API and be unique. The best way to achieve this is by
           * using `public constant` hash digests:
           *
           * ```
           * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
           * ```
           *
           * Roles can be used to represent a set of permissions. To restrict access to a
           * function call, use {hasRole}:
           *
           * ```
           * function foo() public {
           *     require(hasRole(MY_ROLE, msg.sender));
           *     ...
           * }
           * ```
           *
           * Roles can be granted and revoked dynamically via the {grantRole} and
           * {revokeRole} functions. Each role has an associated admin role, and only
           * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
           *
           * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
           * that only accounts with this role will be able to grant or revoke other
           * roles. More complex role relationships can be created by using
           * {_setRoleAdmin}.
           *
           * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
           * grant and revoke this role. Extra precautions should be taken to secure
           * accounts that have been granted it.
           */
          abstract contract AccessControl is Context, IAccessControl, ERC165 {
              struct RoleData {
                  mapping(address => bool) members;
                  bytes32 adminRole;
              }
              mapping(bytes32 => RoleData) private _roles;
              bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
              /**
               * @dev Modifier that checks that an account has a specific role. Reverts
               * with a standardized message including the required role.
               *
               * The format of the revert reason is given by the following regular expression:
               *
               *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
               *
               * _Available since v4.1._
               */
              modifier onlyRole(bytes32 role) {
                  _checkRole(role, _msgSender());
                  _;
              }
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                  return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
              }
              /**
               * @dev Returns `true` if `account` has been granted `role`.
               */
              function hasRole(bytes32 role, address account) public view override returns (bool) {
                  return _roles[role].members[account];
              }
              /**
               * @dev Revert with a standard message if `account` is missing `role`.
               *
               * The format of the revert reason is given by the following regular expression:
               *
               *  /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
               */
              function _checkRole(bytes32 role, address account) internal view {
                  if (!hasRole(role, account)) {
                      revert(
                          string(
                              abi.encodePacked(
                                  "AccessControl: account ",
                                  Strings.toHexString(uint160(account), 20),
                                  " is missing role ",
                                  Strings.toHexString(uint256(role), 32)
                              )
                          )
                      );
                  }
              }
              /**
               * @dev Returns the admin role that controls `role`. See {grantRole} and
               * {revokeRole}.
               *
               * To change a role's admin, use {_setRoleAdmin}.
               */
              function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
                  return _roles[role].adminRole;
              }
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                  _grantRole(role, account);
              }
              /**
               * @dev Revokes `role` from `account`.
               *
               * If `account` had been granted `role`, emits a {RoleRevoked} event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
                  _revokeRole(role, account);
              }
              /**
               * @dev Revokes `role` from the calling account.
               *
               * Roles are often managed via {grantRole} and {revokeRole}: this function's
               * purpose is to provide a mechanism for accounts to lose their privileges
               * if they are compromised (such as when a trusted device is misplaced).
               *
               * If the calling account had been revoked `role`, emits a {RoleRevoked}
               * event.
               *
               * Requirements:
               *
               * - the caller must be `account`.
               */
              function renounceRole(bytes32 role, address account) public virtual override {
                  require(account == _msgSender(), "AccessControl: can only renounce roles for self");
                  _revokeRole(role, account);
              }
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event. Note that unlike {grantRole}, this function doesn't perform any
               * checks on the calling account.
               *
               * [WARNING]
               * ====
               * This function should only be called from the constructor when setting
               * up the initial roles for the system.
               *
               * Using this function in any other way is effectively circumventing the admin
               * system imposed by {AccessControl}.
               * ====
               *
               * NOTE: This function is deprecated in favor of {_grantRole}.
               */
              function _setupRole(bytes32 role, address account) internal virtual {
                  _grantRole(role, account);
              }
              /**
               * @dev Sets `adminRole` as ``role``'s admin role.
               *
               * Emits a {RoleAdminChanged} event.
               */
              function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
                  bytes32 previousAdminRole = getRoleAdmin(role);
                  _roles[role].adminRole = adminRole;
                  emit RoleAdminChanged(role, previousAdminRole, adminRole);
              }
              /**
               * @dev Grants `role` to `account`.
               *
               * Internal function without access restriction.
               */
              function _grantRole(bytes32 role, address account) internal virtual {
                  if (!hasRole(role, account)) {
                      _roles[role].members[account] = true;
                      emit RoleGranted(role, account, _msgSender());
                  }
              }
              /**
               * @dev Revokes `role` from `account`.
               *
               * Internal function without access restriction.
               */
              function _revokeRole(bytes32 role, address account) internal virtual {
                  if (hasRole(role, account)) {
                      _roles[role].members[account] = false;
                      emit RoleRevoked(role, account, _msgSender());
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)
          pragma solidity ^0.8.0;
          import "../utils/Context.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable is Context {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              constructor() {
                  _transferOwnership(_msgSender());
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  _transferOwnership(address(0));
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  _transferOwnership(newOwner);
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Internal function without access restriction.
               */
              function _transferOwnership(address newOwner) internal virtual {
                  address oldOwner = _owner;
                  _owner = newOwner;
                  emit OwnershipTransferred(oldOwner, newOwner);
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (security/Pausable.sol)
          pragma solidity ^0.8.0;
          import "../utils/Context.sol";
          /**
           * @dev Contract module which allows children to implement an emergency stop
           * mechanism that can be triggered by an authorized account.
           *
           * This module is used through inheritance. It will make available the
           * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
           * the functions of your contract. Note that they will not be pausable by
           * simply including this module, only once the modifiers are put in place.
           */
          abstract contract Pausable is Context {
              /**
               * @dev Emitted when the pause is triggered by `account`.
               */
              event Paused(address account);
              /**
               * @dev Emitted when the pause is lifted by `account`.
               */
              event Unpaused(address account);
              bool private _paused;
              /**
               * @dev Initializes the contract in unpaused state.
               */
              constructor() {
                  _paused = false;
              }
              /**
               * @dev Returns true if the contract is paused, and false otherwise.
               */
              function paused() public view virtual returns (bool) {
                  return _paused;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is not paused.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              modifier whenNotPaused() {
                  require(!paused(), "Pausable: paused");
                  _;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is paused.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              modifier whenPaused() {
                  require(paused(), "Pausable: not paused");
                  _;
              }
              /**
               * @dev Triggers stopped state.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              function _pause() internal virtual whenNotPaused {
                  _paused = true;
                  emit Paused(_msgSender());
              }
              /**
               * @dev Returns to normal state.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              function _unpause() internal virtual whenPaused {
                  _paused = false;
                  emit Unpaused(_msgSender());
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Contract module that helps prevent reentrant calls to a function.
           *
           * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
           * available, which can be applied to functions to make sure there are no nested
           * (reentrant) calls to them.
           *
           * Note that because there is a single `nonReentrant` guard, functions marked as
           * `nonReentrant` may not call one another. This can be worked around by making
           * those functions `private`, and then adding `external` `nonReentrant` entry
           * points to them.
           *
           * TIP: If you would like to learn more about reentrancy and alternative ways
           * to protect against it, check out our blog post
           * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
           */
          abstract contract ReentrancyGuard {
              // Booleans are more expensive than uint256 or any type that takes up a full
              // word because each write operation emits an extra SLOAD to first read the
              // slot's contents, replace the bits taken up by the boolean, and then write
              // back. This is the compiler's defense against contract upgrades and
              // pointer aliasing, and it cannot be disabled.
              // The values being non-zero value makes deployment a bit more expensive,
              // but in exchange the refund on every call to nonReentrant will be lower in
              // amount. Since refunds are capped to a percentage of the total
              // transaction's gas, it is best to keep them low in cases like this one, to
              // increase the likelihood of the full refund coming into effect.
              uint256 private constant _NOT_ENTERED = 1;
              uint256 private constant _ENTERED = 2;
              uint256 private _status;
              constructor() {
                  _status = _NOT_ENTERED;
              }
              /**
               * @dev Prevents a contract from calling itself, directly or indirectly.
               * Calling a `nonReentrant` function from another `nonReentrant`
               * function is not supported. It is possible to prevent this from happening
               * by making the `nonReentrant` function external, and making it call a
               * `private` function that does the actual work.
               */
              modifier nonReentrant() {
                  // On the first call to nonReentrant, _notEntered will be true
                  require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                  // Any calls to nonReentrant after this point will fail
                  _status = _ENTERED;
                  _;
                  // By storing the original value once again, a refund is triggered (see
                  // https://eips.ethereum.org/EIPS/eip-2200)
                  _status = _NOT_ENTERED;
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
          pragma solidity ^0.8.0;
          import "../IERC20.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 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'
                  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) + value;
                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
              }
              function safeDecreaseAllowance(
                  IERC20 token,
                  address spender,
                  uint256 value
              ) internal {
                  unchecked {
                      uint256 oldAllowance = token.allowance(address(this), spender);
                      require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                      uint256 newAllowance = oldAllowance - value;
                      _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
                      require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Address.sol)
          pragma solidity ^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;
                  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");
                  (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");
                  (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");
                  (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");
                  (bool success, bytes memory returndata) = target.delegatecall(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
               * revert reason using the provided one.
               *
               * _Available since v4.3._
               */
              function verifyCallResult(
                  bool success,
                  bytes memory returndata,
                  string memory errorMessage
              ) internal 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
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract Context {
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  return msg.data;
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC20 standard as defined in the EIP.
           */
          interface IERC20 {
              /**
               * @dev Returns the amount of tokens in existence.
               */
              function totalSupply() external view returns (uint256);
              /**
               * @dev Returns the amount of tokens owned by `account`.
               */
              function balanceOf(address account) external view returns (uint256);
              /**
               * @dev Moves `amount` tokens from the caller's account to `recipient`.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * Emits a {Transfer} event.
               */
              function transfer(address recipient, uint256 amount) external returns (bool);
              /**
               * @dev Returns the remaining number of tokens that `spender` will be
               * allowed to spend on behalf of `owner` through {transferFrom}. This is
               * zero by default.
               *
               * This value changes when {approve} or {transferFrom} are called.
               */
              function allowance(address owner, address spender) external view returns (uint256);
              /**
               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * IMPORTANT: Beware that changing an allowance with this method brings the risk
               * that someone may use both the old and the new allowance by unfortunate
               * transaction ordering. One possible solution to mitigate this race
               * condition is to first reduce the spender's allowance to 0 and set the
               * desired value afterwards:
               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
               *
               * Emits an {Approval} event.
               */
              function approve(address spender, uint256 amount) external returns (bool);
              /**
               * @dev Moves `amount` tokens from `sender` to `recipient` using the
               * allowance mechanism. `amount` is then deducted from the caller's
               * allowance.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * Emits a {Transfer} event.
               */
              function transferFrom(
                  address sender,
                  address recipient,
                  uint256 amount
              ) external returns (bool);
              /**
               * @dev Emitted when `value` tokens are moved from one account (`from`) to
               * another (`to`).
               *
               * Note that `value` may be zero.
               */
              event Transfer(address indexed from, address indexed to, uint256 value);
              /**
               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
               * a call to {approve}. `value` is the new allowance.
               */
              event Approval(address indexed owner, address indexed spender, uint256 value);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/structs/EnumerableSet.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Library for managing
           * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
           * types.
           *
           * Sets have the following properties:
           *
           * - Elements are added, removed, and checked for existence in constant time
           * (O(1)).
           * - Elements are enumerated in O(n). No guarantees are made on the ordering.
           *
           * ```
           * contract Example {
           *     // Add the library methods
           *     using EnumerableSet for EnumerableSet.AddressSet;
           *
           *     // Declare a set state variable
           *     EnumerableSet.AddressSet private mySet;
           * }
           * ```
           *
           * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
           * and `uint256` (`UintSet`) are supported.
           */
          library EnumerableSet {
              // To implement this library for multiple types with as little code
              // repetition as possible, we write it in terms of a generic Set type with
              // bytes32 values.
              // The Set implementation uses private functions, and user-facing
              // implementations (such as AddressSet) are just wrappers around the
              // underlying Set.
              // This means that we can only create new EnumerableSets for types that fit
              // in bytes32.
              struct Set {
                  // Storage of set values
                  bytes32[] _values;
                  // Position of the value in the `values` array, plus 1 because index 0
                  // means a value is not in the set.
                  mapping(bytes32 => uint256) _indexes;
              }
              /**
               * @dev Add a value to a set. O(1).
               *
               * Returns true if the value was added to the set, that is if it was not
               * already present.
               */
              function _add(Set storage set, bytes32 value) private returns (bool) {
                  if (!_contains(set, value)) {
                      set._values.push(value);
                      // The value is stored at length-1, but we add 1 to all indexes
                      // and use 0 as a sentinel value
                      set._indexes[value] = set._values.length;
                      return true;
                  } else {
                      return false;
                  }
              }
              /**
               * @dev Removes a value from a set. O(1).
               *
               * Returns true if the value was removed from the set, that is if it was
               * present.
               */
              function _remove(Set storage set, bytes32 value) private returns (bool) {
                  // We read and store the value's index to prevent multiple reads from the same storage slot
                  uint256 valueIndex = set._indexes[value];
                  if (valueIndex != 0) {
                      // Equivalent to contains(set, value)
                      // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                      // the array, and then remove the last element (sometimes called as 'swap and pop').
                      // This modifies the order of the array, as noted in {at}.
                      uint256 toDeleteIndex = valueIndex - 1;
                      uint256 lastIndex = set._values.length - 1;
                      if (lastIndex != toDeleteIndex) {
                          bytes32 lastvalue = set._values[lastIndex];
                          // Move the last value to the index where the value to delete is
                          set._values[toDeleteIndex] = lastvalue;
                          // Update the index for the moved value
                          set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
                      }
                      // Delete the slot where the moved value was stored
                      set._values.pop();
                      // Delete the index for the deleted slot
                      delete set._indexes[value];
                      return true;
                  } else {
                      return false;
                  }
              }
              /**
               * @dev Returns true if the value is in the set. O(1).
               */
              function _contains(Set storage set, bytes32 value) private view returns (bool) {
                  return set._indexes[value] != 0;
              }
              /**
               * @dev Returns the number of values on the set. O(1).
               */
              function _length(Set storage set) private view returns (uint256) {
                  return set._values.length;
              }
              /**
               * @dev Returns the value stored at position `index` in the set. O(1).
               *
               * Note that there are no guarantees on the ordering of values inside the
               * array, and it may change when more values are added or removed.
               *
               * Requirements:
               *
               * - `index` must be strictly less than {length}.
               */
              function _at(Set storage set, uint256 index) private view returns (bytes32) {
                  return set._values[index];
              }
              /**
               * @dev Return the entire set in an array
               *
               * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
               * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
               * this function has an unbounded cost, and using it as part of a state-changing function may render the function
               * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
               */
              function _values(Set storage set) private view returns (bytes32[] memory) {
                  return set._values;
              }
              // Bytes32Set
              struct Bytes32Set {
                  Set _inner;
              }
              /**
               * @dev Add a value to a set. O(1).
               *
               * Returns true if the value was added to the set, that is if it was not
               * already present.
               */
              function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                  return _add(set._inner, value);
              }
              /**
               * @dev Removes a value from a set. O(1).
               *
               * Returns true if the value was removed from the set, that is if it was
               * present.
               */
              function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                  return _remove(set._inner, value);
              }
              /**
               * @dev Returns true if the value is in the set. O(1).
               */
              function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
                  return _contains(set._inner, value);
              }
              /**
               * @dev Returns the number of values in the set. O(1).
               */
              function length(Bytes32Set storage set) internal view returns (uint256) {
                  return _length(set._inner);
              }
              /**
               * @dev Returns the value stored at position `index` in the set. O(1).
               *
               * Note that there are no guarantees on the ordering of values inside the
               * array, and it may change when more values are added or removed.
               *
               * Requirements:
               *
               * - `index` must be strictly less than {length}.
               */
              function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
                  return _at(set._inner, index);
              }
              /**
               * @dev Return the entire set in an array
               *
               * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
               * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
               * this function has an unbounded cost, and using it as part of a state-changing function may render the function
               * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
               */
              function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
                  return _values(set._inner);
              }
              // AddressSet
              struct AddressSet {
                  Set _inner;
              }
              /**
               * @dev Add a value to a set. O(1).
               *
               * Returns true if the value was added to the set, that is if it was not
               * already present.
               */
              function add(AddressSet storage set, address value) internal returns (bool) {
                  return _add(set._inner, bytes32(uint256(uint160(value))));
              }
              /**
               * @dev Removes a value from a set. O(1).
               *
               * Returns true if the value was removed from the set, that is if it was
               * present.
               */
              function remove(AddressSet storage set, address value) internal returns (bool) {
                  return _remove(set._inner, bytes32(uint256(uint160(value))));
              }
              /**
               * @dev Returns true if the value is in the set. O(1).
               */
              function contains(AddressSet storage set, address value) internal view returns (bool) {
                  return _contains(set._inner, bytes32(uint256(uint160(value))));
              }
              /**
               * @dev Returns the number of values in the set. O(1).
               */
              function length(AddressSet storage set) internal view returns (uint256) {
                  return _length(set._inner);
              }
              /**
               * @dev Returns the value stored at position `index` in the set. O(1).
               *
               * Note that there are no guarantees on the ordering of values inside the
               * array, and it may change when more values are added or removed.
               *
               * Requirements:
               *
               * - `index` must be strictly less than {length}.
               */
              function at(AddressSet storage set, uint256 index) internal view returns (address) {
                  return address(uint160(uint256(_at(set._inner, index))));
              }
              /**
               * @dev Return the entire set in an array
               *
               * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
               * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
               * this function has an unbounded cost, and using it as part of a state-changing function may render the function
               * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
               */
              function values(AddressSet storage set) internal view returns (address[] memory) {
                  bytes32[] memory store = _values(set._inner);
                  address[] memory result;
                  assembly {
                      result := store
                  }
                  return result;
              }
              // UintSet
              struct UintSet {
                  Set _inner;
              }
              /**
               * @dev Add a value to a set. O(1).
               *
               * Returns true if the value was added to the set, that is if it was not
               * already present.
               */
              function add(UintSet storage set, uint256 value) internal returns (bool) {
                  return _add(set._inner, bytes32(value));
              }
              /**
               * @dev Removes a value from a set. O(1).
               *
               * Returns true if the value was removed from the set, that is if it was
               * present.
               */
              function remove(UintSet storage set, uint256 value) internal returns (bool) {
                  return _remove(set._inner, bytes32(value));
              }
              /**
               * @dev Returns true if the value is in the set. O(1).
               */
              function contains(UintSet storage set, uint256 value) internal view returns (bool) {
                  return _contains(set._inner, bytes32(value));
              }
              /**
               * @dev Returns the number of values on the set. O(1).
               */
              function length(UintSet storage set) internal view returns (uint256) {
                  return _length(set._inner);
              }
              /**
               * @dev Returns the value stored at position `index` in the set. O(1).
               *
               * Note that there are no guarantees on the ordering of values inside the
               * array, and it may change when more values are added or removed.
               *
               * Requirements:
               *
               * - `index` must be strictly less than {length}.
               */
              function at(UintSet storage set, uint256 index) internal view returns (uint256) {
                  return uint256(_at(set._inner, index));
              }
              /**
               * @dev Return the entire set in an array
               *
               * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
               * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
               * this function has an unbounded cost, and using it as part of a state-changing function may render the function
               * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
               */
              function values(UintSet storage set) internal view returns (uint256[] memory) {
                  bytes32[] memory store = _values(set._inner);
                  uint256[] memory result;
                  assembly {
                      result := store
                  }
                  return result;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import {AccessControl} from '@openzeppelin/contracts/access/AccessControl.sol';
          import {IERC20, SafeERC20} from '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
          import {ReentrancyGuard} from '@openzeppelin/contracts/security/ReentrancyGuard.sol';
          import {TokenDistributor} from './TokenDistributor.sol';
          import {IStakeFor} from './IStakeFor.sol';
          /**
           * @title FeeSharingSystem
           * @notice It handles the distribution of fees using
           * WETH along with the auto-compounding of X2Y2.
           */
          contract FeeSharingSystem is ReentrancyGuard, AccessControl, IStakeFor {
              using SafeERC20 for IERC20;
              // for `depositFor` call
              bytes32 public constant DEPOSIT_ROLE = keccak256('DEPOSIT_ROLE');
              // for `updateRewards()`
              bytes32 public constant REWARD_UPDATE_ROLE = keccak256('REWARD_UPDATE_ROLE');
              struct UserInfo {
                  uint256 shares; // shares of token staked
                  uint256 userRewardPerTokenPaid; // user reward per token paid
                  uint256 rewards; // pending rewards
              }
              // Precision factor for calculating rewards and exchange rate
              uint256 public constant PRECISION_FACTOR = 10**18;
              IERC20 public immutable x2y2Token;
              IERC20 public immutable rewardToken;
              TokenDistributor public immutable tokenDistributor;
              // Reward rate (block)
              uint256 public currentRewardPerBlock;
              // Last reward adjustment block number
              uint256 public lastRewardAdjustment;
              // Last update block for rewards
              uint256 public lastUpdateBlock;
              // Current end block for the current reward period
              uint256 public periodEndBlock;
              // Reward per token stored
              uint256 public rewardPerTokenStored;
              // Total existing shares
              uint256 public totalShares;
              mapping(address => UserInfo) public userInfo;
              event Deposit(address indexed user, uint256 amount, uint256 harvestedAmount);
              event Harvest(address indexed user, uint256 harvestedAmount);
              event NewRewardPeriod(uint256 numberBlocks, uint256 rewardPerBlock, uint256 reward);
              event Withdraw(address indexed user, uint256 amount, uint256 harvestedAmount);
              /**
               * @notice Constructor
               * @param _x2y2Token address of the token staked
               * @param _rewardToken address of the reward token
               * @param _tokenDistributor address of the token distributor contract
               */
              constructor(
                  address _x2y2Token,
                  address _rewardToken,
                  address _tokenDistributor
              ) {
                  rewardToken = IERC20(_rewardToken);
                  x2y2Token = IERC20(_x2y2Token);
                  tokenDistributor = TokenDistributor(_tokenDistributor);
                  _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
              }
              /**
               * @notice deposit on behalf of `user`, must be called on fresh deposit only
               * @param user deposit user
               * @param amount amount to deposit
               */
              function depositFor(address user, uint256 amount)
                  external
                  override
                  nonReentrant
                  onlyRole(DEPOSIT_ROLE)
                  returns (bool)
              {
                  require(amount >= PRECISION_FACTOR, 'Deposit: Amount must be >= 1 X2Y2');
                  // Auto compounds for everyone
                  tokenDistributor.harvestAndCompound();
                  // Update reward for user
                  _updateReward(user);
                  // Retrieve total amount staked by this contract
                  (uint256 totalAmountStaked, ) = tokenDistributor.userInfo(address(this));
                  // transfer stakingToken from **sender**
                  x2y2Token.safeTransferFrom(msg.sender, address(this), amount);
                  uint256 currentShares;
                  // Calculate the number of shares to issue for the user
                  if (totalShares != 0) {
                      currentShares = (amount * totalShares) / totalAmountStaked;
                      // This is a sanity check to prevent deposit for 0 shares
                      require(currentShares != 0, 'Deposit: Fail');
                  } else {
                      currentShares = amount;
                  }
                  // Adjust internal shares
                  userInfo[user].shares += currentShares;
                  totalShares += currentShares;
                  // Verify X2Y2 token allowance and adjust if necessary
                  _checkAndAdjustX2Y2TokenAllowanceIfRequired(amount, address(tokenDistributor));
                  // Deposit user amount in the token distributor contract
                  tokenDistributor.deposit(amount);
                  emit Deposit(user, amount, 0);
                  return true;
              }
              /**
               * @notice Deposit staked tokens (and collect reward tokens if requested)
               * @param amount amount to deposit (in X2Y2)
               * @param claimRewardToken whether to claim reward tokens
               * @dev There is a limit of 1 X2Y2 per deposit to prevent potential manipulation of current shares
               */
              function deposit(uint256 amount, bool claimRewardToken) external nonReentrant {
                  require(amount >= PRECISION_FACTOR, 'Deposit: Amount must be >= 1 X2Y2');
                  // Auto compounds for everyone
                  tokenDistributor.harvestAndCompound();
                  // Update reward for user
                  _updateReward(msg.sender);
                  // Retrieve total amount staked by this contract
                  (uint256 totalAmountStaked, ) = tokenDistributor.userInfo(address(this));
                  // Transfer X2Y2 tokens to this address
                  x2y2Token.safeTransferFrom(msg.sender, address(this), amount);
                  uint256 currentShares;
                  // Calculate the number of shares to issue for the user
                  if (totalShares != 0) {
                      currentShares = (amount * totalShares) / totalAmountStaked;
                      // This is a sanity check to prevent deposit for 0 shares
                      require(currentShares != 0, 'Deposit: Fail');
                  } else {
                      currentShares = amount;
                  }
                  // Adjust internal shares
                  userInfo[msg.sender].shares += currentShares;
                  totalShares += currentShares;
                  uint256 pendingRewards;
                  if (claimRewardToken) {
                      // Fetch pending rewards
                      pendingRewards = userInfo[msg.sender].rewards;
                      if (pendingRewards > 0) {
                          userInfo[msg.sender].rewards = 0;
                          rewardToken.safeTransfer(msg.sender, pendingRewards);
                      }
                  }
                  // Verify X2Y2 token allowance and adjust if necessary
                  _checkAndAdjustX2Y2TokenAllowanceIfRequired(amount, address(tokenDistributor));
                  // Deposit user amount in the token distributor contract
                  tokenDistributor.deposit(amount);
                  emit Deposit(msg.sender, amount, pendingRewards);
              }
              /**
               * @notice Harvest reward tokens that are pending
               */
              function harvest() external nonReentrant {
                  // Auto compounds for everyone
                  tokenDistributor.harvestAndCompound();
                  // Update reward for user
                  _updateReward(msg.sender);
                  // Retrieve pending rewards
                  uint256 pendingRewards = userInfo[msg.sender].rewards;
                  // If pending rewards are null, revert
                  require(pendingRewards > 0, 'Harvest: Pending rewards must be > 0');
                  // Adjust user rewards and transfer
                  userInfo[msg.sender].rewards = 0;
                  // Transfer reward token to sender
                  rewardToken.safeTransfer(msg.sender, pendingRewards);
                  emit Harvest(msg.sender, pendingRewards);
              }
              /**
               * @notice Withdraw staked tokens (and collect reward tokens if requested)
               * @param shares shares to withdraw
               * @param claimRewardToken whether to claim reward tokens
               */
              function withdraw(uint256 shares, bool claimRewardToken) external nonReentrant {
                  require(
                      (shares > 0) && (shares <= userInfo[msg.sender].shares),
                      'Withdraw: Shares equal to 0 or larger than user shares'
                  );
                  _withdraw(shares, claimRewardToken);
              }
              /**
               * @notice Withdraw all staked tokens (and collect reward tokens if requested)
               * @param claimRewardToken whether to claim reward tokens
               */
              function withdrawAll(bool claimRewardToken) external nonReentrant {
                  _withdraw(userInfo[msg.sender].shares, claimRewardToken);
              }
              /**
               * @notice Update the reward per block (in rewardToken)
               * @dev Only callable by owner. Owner is meant to be another smart contract.
               */
              function updateRewards(uint256 reward, uint256 rewardDurationInBlocks)
                  external
                  onlyRole(REWARD_UPDATE_ROLE)
              {
                  // Adjust the current reward per block
                  if (block.number >= periodEndBlock) {
                      currentRewardPerBlock = reward / rewardDurationInBlocks;
                  } else {
                      currentRewardPerBlock =
                          (reward + ((periodEndBlock - block.number) * currentRewardPerBlock)) /
                          rewardDurationInBlocks;
                  }
                  lastUpdateBlock = block.number;
                  periodEndBlock = block.number + rewardDurationInBlocks;
                  emit NewRewardPeriod(rewardDurationInBlocks, currentRewardPerBlock, reward);
              }
              /**
               * @notice Calculate pending rewards (WETH) for a user
               * @param user address of the user
               */
              function calculatePendingRewards(address user) external view returns (uint256) {
                  return _calculatePendingRewards(user);
              }
              /**
               * @notice Calculate value of X2Y2 for a user given a number of shares owned
               * @param user address of the user
               */
              function calculateSharesValueInX2Y2(address user) external view returns (uint256) {
                  // Retrieve amount staked
                  (uint256 totalAmountStaked, ) = tokenDistributor.userInfo(address(this));
                  // Adjust for pending rewards
                  totalAmountStaked += tokenDistributor.calculatePendingRewards(address(this));
                  // Return user pro-rata of total shares
                  return
                      userInfo[user].shares == 0
                          ? 0
                          : (totalAmountStaked * userInfo[user].shares) / totalShares;
              }
              /**
               * @notice Calculate price of one share (in X2Y2 token)
               * Share price is expressed times 1e18
               */
              function calculateSharePriceInX2Y2() external view returns (uint256) {
                  (uint256 totalAmountStaked, ) = tokenDistributor.userInfo(address(this));
                  // Adjust for pending rewards
                  totalAmountStaked += tokenDistributor.calculatePendingRewards(address(this));
                  return
                      totalShares == 0
                          ? PRECISION_FACTOR
                          : (totalAmountStaked * PRECISION_FACTOR) / (totalShares);
              }
              /**
               * @notice Return last block where trading rewards were distributed
               */
              function lastRewardBlock() external view returns (uint256) {
                  return _lastRewardBlock();
              }
              /**
               * @notice Calculate pending rewards for a user
               * @param user address of the user
               */
              function _calculatePendingRewards(address user) internal view returns (uint256) {
                  return
                      ((userInfo[user].shares *
                          (_rewardPerToken() - (userInfo[user].userRewardPerTokenPaid))) / PRECISION_FACTOR) +
                      userInfo[user].rewards;
              }
              /**
               * @notice Check current allowance and adjust if necessary
               * @param _amount amount to transfer
               * @param _to token to transfer
               */
              function _checkAndAdjustX2Y2TokenAllowanceIfRequired(uint256 _amount, address _to) internal {
                  if (x2y2Token.allowance(address(this), _to) < _amount) {
                      x2y2Token.approve(_to, type(uint256).max);
                  }
              }
              /**
               * @notice Return last block where rewards must be distributed
               */
              function _lastRewardBlock() internal view returns (uint256) {
                  return block.number < periodEndBlock ? block.number : periodEndBlock;
              }
              /**
               * @notice Return reward per token
               */
              function _rewardPerToken() internal view returns (uint256) {
                  if (totalShares == 0) {
                      return rewardPerTokenStored;
                  }
                  return
                      rewardPerTokenStored +
                      ((_lastRewardBlock() - lastUpdateBlock) * (currentRewardPerBlock * PRECISION_FACTOR)) /
                      totalShares;
              }
              /**
               * @notice Update reward for a user account
               * @param _user address of the user
               */
              function _updateReward(address _user) internal {
                  if (block.number != lastUpdateBlock) {
                      rewardPerTokenStored = _rewardPerToken();
                      lastUpdateBlock = _lastRewardBlock();
                  }
                  userInfo[_user].rewards = _calculatePendingRewards(_user);
                  userInfo[_user].userRewardPerTokenPaid = rewardPerTokenStored;
              }
              /**
               * @notice Withdraw staked tokens (and collect reward tokens if requested)
               * @param shares shares to withdraw
               * @param claimRewardToken whether to claim reward tokens
               */
              function _withdraw(uint256 shares, bool claimRewardToken) internal {
                  // Auto compounds for everyone
                  tokenDistributor.harvestAndCompound();
                  // Update reward for user
                  _updateReward(msg.sender);
                  // Retrieve total amount staked and calculated current amount (in X2Y2)
                  (uint256 totalAmountStaked, ) = tokenDistributor.userInfo(address(this));
                  uint256 currentAmount = (totalAmountStaked * shares) / totalShares;
                  userInfo[msg.sender].shares -= shares;
                  totalShares -= shares;
                  // Withdraw amount equivalent in shares
                  tokenDistributor.withdraw(currentAmount);
                  uint256 pendingRewards;
                  if (claimRewardToken) {
                      // Fetch pending rewards
                      pendingRewards = userInfo[msg.sender].rewards;
                      if (pendingRewards > 0) {
                          userInfo[msg.sender].rewards = 0;
                          rewardToken.safeTransfer(msg.sender, pendingRewards);
                      }
                  }
                  // Transfer X2Y2 tokens to sender
                  x2y2Token.safeTransfer(msg.sender, currentAmount);
                  emit Withdraw(msg.sender, currentAmount, pendingRewards);
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import {ReentrancyGuard} from '@openzeppelin/contracts/security/ReentrancyGuard.sol';
          import {IERC20, SafeERC20} from '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
          import {IMintableERC20} from './IMintableERC20.sol';
          /**
           * @title TokenDistributor
           * @notice It handles the distribution of X2Y2 token.
           * It auto-adjusts block rewards over a set number of periods.
           */
          contract TokenDistributor is ReentrancyGuard {
              using SafeERC20 for IERC20;
              using SafeERC20 for IMintableERC20;
              struct StakingPeriod {
                  uint256 rewardPerBlockForStaking;
                  uint256 rewardPerBlockForOthers;
                  uint256 periodLengthInBlock;
              }
              struct UserInfo {
                  uint256 amount; // Amount of staked tokens provided by user
                  uint256 rewardDebt; // Reward debt
              }
              // Precision factor for calculating rewards
              uint256 public constant PRECISION_FACTOR = 10**12;
              IMintableERC20 public immutable x2y2Token;
              address public immutable tokenSplitter;
              // Number of reward periods
              uint256 public immutable NUMBER_PERIODS;
              // Block number when rewards start
              uint256 public immutable START_BLOCK;
              // Accumulated tokens per share
              uint256 public accTokenPerShare;
              // Current phase for rewards
              uint256 public currentPhase;
              // Block number when rewards end
              uint256 public endBlock;
              // Block number of the last update
              uint256 public lastRewardBlock;
              // Tokens distributed per block for other purposes (team + treasury + trading rewards)
              uint256 public rewardPerBlockForOthers;
              // Tokens distributed per block for staking
              uint256 public rewardPerBlockForStaking;
              // Total amount staked
              uint256 public totalAmountStaked;
              mapping(uint256 => StakingPeriod) public stakingPeriod;
              mapping(address => UserInfo) public userInfo;
              event Compound(address indexed user, uint256 harvestedAmount);
              event Deposit(address indexed user, uint256 amount, uint256 harvestedAmount);
              event NewRewardsPerBlock(
                  uint256 indexed currentPhase,
                  uint256 startBlock,
                  uint256 rewardPerBlockForStaking,
                  uint256 rewardPerBlockForOthers
              );
              event Withdraw(address indexed user, uint256 amount, uint256 harvestedAmount);
              /**
               * @notice Constructor
               * @param _x2y2Token token address
               * @param _tokenSplitter token splitter contract address (for team and trading rewards)
               * @param _startBlock start block for reward program
               * @param _rewardsPerBlockForStaking array of rewards per block for staking
               * @param _rewardsPerBlockForOthers array of rewards per block for other purposes (team + treasury + trading rewards)
               * @param _periodLengthesInBlocks array of period lengthes
               * @param _numberPeriods number of periods with different rewards/lengthes (e.g., if 3 changes --> 4 periods)
               */
              constructor(
                  address _x2y2Token,
                  address _tokenSplitter,
                  uint256 _startBlock,
                  uint256[] memory _rewardsPerBlockForStaking,
                  uint256[] memory _rewardsPerBlockForOthers,
                  uint256[] memory _periodLengthesInBlocks,
                  uint256 _numberPeriods
              ) {
                  require(
                      (_periodLengthesInBlocks.length == _numberPeriods) &&
                          (_rewardsPerBlockForStaking.length == _numberPeriods) &&
                          (_rewardsPerBlockForStaking.length == _numberPeriods),
                      'Distributor: Lengthes must match numberPeriods'
                  );
                  // 1. Operational checks for supply
                  uint256 nonCirculatingSupply = IMintableERC20(_x2y2Token).SUPPLY_CAP() -
                      IMintableERC20(_x2y2Token).totalSupply();
                  uint256 amountTokensToBeMinted;
                  for (uint256 i = 0; i < _numberPeriods; i++) {
                      amountTokensToBeMinted +=
                          (_rewardsPerBlockForStaking[i] * _periodLengthesInBlocks[i]) +
                          (_rewardsPerBlockForOthers[i] * _periodLengthesInBlocks[i]);
                      stakingPeriod[i] = StakingPeriod({
                          rewardPerBlockForStaking: _rewardsPerBlockForStaking[i],
                          rewardPerBlockForOthers: _rewardsPerBlockForOthers[i],
                          periodLengthInBlock: _periodLengthesInBlocks[i]
                      });
                  }
                  require(
                      amountTokensToBeMinted == nonCirculatingSupply,
                      'Distributor: Wrong reward parameters'
                  );
                  // 2. Store values
                  x2y2Token = IMintableERC20(_x2y2Token);
                  tokenSplitter = _tokenSplitter;
                  rewardPerBlockForStaking = _rewardsPerBlockForStaking[0];
                  rewardPerBlockForOthers = _rewardsPerBlockForOthers[0];
                  START_BLOCK = _startBlock;
                  endBlock = _startBlock + _periodLengthesInBlocks[0];
                  NUMBER_PERIODS = _numberPeriods;
                  // Set the lastRewardBlock as the startBlock
                  lastRewardBlock = _startBlock;
              }
              /**
               * @notice Deposit staked tokens and compounds pending rewards
               * @param amount amount to deposit (in X2Y2)
               */
              function deposit(uint256 amount) external nonReentrant {
                  require(amount > 0, 'Deposit: Amount must be > 0');
                  require(block.number >= START_BLOCK, 'Deposit: Not started yet');
                  // Update pool information
                  _updatePool();
                  // Transfer X2Y2 tokens to this contract
                  x2y2Token.safeTransferFrom(msg.sender, address(this), amount);
                  uint256 pendingRewards;
                  // If not new deposit, calculate pending rewards (for auto-compounding)
                  if (userInfo[msg.sender].amount > 0) {
                      pendingRewards =
                          ((userInfo[msg.sender].amount * accTokenPerShare) / PRECISION_FACTOR) -
                          userInfo[msg.sender].rewardDebt;
                  }
                  // Adjust user information
                  userInfo[msg.sender].amount += (amount + pendingRewards);
                  userInfo[msg.sender].rewardDebt =
                      (userInfo[msg.sender].amount * accTokenPerShare) /
                      PRECISION_FACTOR;
                  // Increase totalAmountStaked
                  totalAmountStaked += (amount + pendingRewards);
                  emit Deposit(msg.sender, amount, pendingRewards);
              }
              /**
               * @notice Compound based on pending rewards
               */
              function harvestAndCompound() external nonReentrant {
                  // Update pool information
                  _updatePool();
                  // Calculate pending rewards
                  uint256 pendingRewards = ((userInfo[msg.sender].amount * accTokenPerShare) /
                      PRECISION_FACTOR) - userInfo[msg.sender].rewardDebt;
                  // Return if no pending rewards
                  if (pendingRewards == 0) {
                      // It doesn't throw revertion (to help with the fee-sharing auto-compounding contract)
                      return;
                  }
                  // Adjust user amount for pending rewards
                  userInfo[msg.sender].amount += pendingRewards;
                  // Adjust totalAmountStaked
                  totalAmountStaked += pendingRewards;
                  // Recalculate reward debt based on new user amount
                  userInfo[msg.sender].rewardDebt =
                      (userInfo[msg.sender].amount * accTokenPerShare) /
                      PRECISION_FACTOR;
                  emit Compound(msg.sender, pendingRewards);
              }
              /**
               * @notice Update pool rewards
               */
              function updatePool() external nonReentrant {
                  _updatePool();
              }
              /**
               * @notice Withdraw staked tokens and compound pending rewards
               * @param amount amount to withdraw
               */
              function withdraw(uint256 amount) external nonReentrant {
                  require(
                      (userInfo[msg.sender].amount >= amount) && (amount > 0),
                      'Withdraw: Amount must be > 0 or lower than user balance'
                  );
                  // Update pool
                  _updatePool();
                  // Calculate pending rewards
                  uint256 pendingRewards = ((userInfo[msg.sender].amount * accTokenPerShare) /
                      PRECISION_FACTOR) - userInfo[msg.sender].rewardDebt;
                  // Adjust user information
                  userInfo[msg.sender].amount = userInfo[msg.sender].amount + pendingRewards - amount;
                  userInfo[msg.sender].rewardDebt =
                      (userInfo[msg.sender].amount * accTokenPerShare) /
                      PRECISION_FACTOR;
                  // Adjust total amount staked
                  totalAmountStaked = totalAmountStaked + pendingRewards - amount;
                  // Transfer X2Y2 tokens to the sender
                  x2y2Token.safeTransfer(msg.sender, amount);
                  emit Withdraw(msg.sender, amount, pendingRewards);
              }
              /**
               * @notice Withdraw all staked tokens and collect tokens
               */
              function withdrawAll() external nonReentrant {
                  require(userInfo[msg.sender].amount > 0, 'Withdraw: Amount must be > 0');
                  // Update pool
                  _updatePool();
                  // Calculate pending rewards and amount to transfer (to the sender)
                  uint256 pendingRewards = ((userInfo[msg.sender].amount * accTokenPerShare) /
                      PRECISION_FACTOR) - userInfo[msg.sender].rewardDebt;
                  uint256 amountToTransfer = userInfo[msg.sender].amount + pendingRewards;
                  // Adjust total amount staked
                  totalAmountStaked = totalAmountStaked - userInfo[msg.sender].amount;
                  // Adjust user information
                  userInfo[msg.sender].amount = 0;
                  userInfo[msg.sender].rewardDebt = 0;
                  // Transfer X2Y2 tokens to the sender
                  x2y2Token.safeTransfer(msg.sender, amountToTransfer);
                  emit Withdraw(msg.sender, amountToTransfer, pendingRewards);
              }
              /**
               * @notice Calculate pending rewards for a user
               * @param user address of the user
               * @return Pending rewards
               */
              function calculatePendingRewards(address user) external view returns (uint256) {
                  if ((block.number > lastRewardBlock) && (totalAmountStaked != 0)) {
                      uint256 multiplier = _getMultiplier(lastRewardBlock, block.number);
                      uint256 tokenRewardForStaking = multiplier * rewardPerBlockForStaking;
                      uint256 adjustedEndBlock = endBlock;
                      uint256 adjustedCurrentPhase = currentPhase;
                      // Check whether to adjust multipliers and reward per block
                      while (
                          (block.number > adjustedEndBlock) && (adjustedCurrentPhase < (NUMBER_PERIODS - 1))
                      ) {
                          // Update current phase
                          adjustedCurrentPhase++;
                          // Update rewards per block
                          uint256 adjustedRewardPerBlockForStaking = stakingPeriod[adjustedCurrentPhase]
                              .rewardPerBlockForStaking;
                          // Calculate adjusted block number
                          uint256 previousEndBlock = adjustedEndBlock;
                          // Update end block
                          adjustedEndBlock =
                              previousEndBlock +
                              stakingPeriod[adjustedCurrentPhase].periodLengthInBlock;
                          // Calculate new multiplier
                          uint256 newMultiplier = (block.number <= adjustedEndBlock)
                              ? (block.number - previousEndBlock)
                              : stakingPeriod[adjustedCurrentPhase].periodLengthInBlock;
                          // Adjust token rewards for staking
                          tokenRewardForStaking += (newMultiplier * adjustedRewardPerBlockForStaking);
                      }
                      uint256 adjustedTokenPerShare = accTokenPerShare +
                          (tokenRewardForStaking * PRECISION_FACTOR) /
                          totalAmountStaked;
                      return
                          (userInfo[user].amount * adjustedTokenPerShare) /
                          PRECISION_FACTOR -
                          userInfo[user].rewardDebt;
                  } else {
                      return
                          (userInfo[user].amount * accTokenPerShare) /
                          PRECISION_FACTOR -
                          userInfo[user].rewardDebt;
                  }
              }
              /**
               * @notice Update reward variables of the pool
               */
              function _updatePool() internal {
                  if (block.number <= lastRewardBlock) {
                      return;
                  }
                  if (totalAmountStaked == 0) {
                      lastRewardBlock = block.number;
                      return;
                  }
                  // Calculate multiplier
                  uint256 multiplier = _getMultiplier(lastRewardBlock, block.number);
                  // Calculate rewards for staking and others
                  uint256 tokenRewardForStaking = multiplier * rewardPerBlockForStaking;
                  uint256 tokenRewardForOthers = multiplier * rewardPerBlockForOthers;
                  // Check whether to adjust multipliers and reward per block
                  while ((block.number > endBlock) && (currentPhase < (NUMBER_PERIODS - 1))) {
                      // Update rewards per block
                      _updateRewardsPerBlock(endBlock);
                      uint256 previousEndBlock = endBlock;
                      // Adjust the end block
                      endBlock += stakingPeriod[currentPhase].periodLengthInBlock;
                      // Adjust multiplier to cover the missing periods with other lower inflation schedule
                      uint256 newMultiplier = _getMultiplier(previousEndBlock, block.number);
                      // Adjust token rewards
                      tokenRewardForStaking += (newMultiplier * rewardPerBlockForStaking);
                      tokenRewardForOthers += (newMultiplier * rewardPerBlockForOthers);
                  }
                  // Mint tokens only if token rewards for staking are not null
                  if (tokenRewardForStaking > 0) {
                      // It allows protection against potential issues to prevent funds from being locked
                      bool mintStatus = x2y2Token.mint(address(this), tokenRewardForStaking);
                      if (mintStatus) {
                          accTokenPerShare =
                              accTokenPerShare +
                              ((tokenRewardForStaking * PRECISION_FACTOR) / totalAmountStaked);
                      }
                      x2y2Token.mint(tokenSplitter, tokenRewardForOthers);
                  }
                  // Update last reward block only if it wasn't updated after or at the end block
                  if (lastRewardBlock <= endBlock) {
                      lastRewardBlock = block.number;
                  }
              }
              /**
               * @notice Update rewards per block
               * @dev Rewards are halved by 2 (for staking + others)
               */
              function _updateRewardsPerBlock(uint256 _newStartBlock) internal {
                  // Update current phase
                  currentPhase++;
                  // Update rewards per block
                  rewardPerBlockForStaking = stakingPeriod[currentPhase].rewardPerBlockForStaking;
                  rewardPerBlockForOthers = stakingPeriod[currentPhase].rewardPerBlockForOthers;
                  emit NewRewardsPerBlock(
                      currentPhase,
                      _newStartBlock,
                      rewardPerBlockForStaking,
                      rewardPerBlockForOthers
                  );
              }
              /**
               * @notice Return reward multiplier over the given "from" to "to" block.
               * @param from block to start calculating reward
               * @param to block to finish calculating reward
               * @return the multiplier for the period
               */
              function _getMultiplier(uint256 from, uint256 to) internal view returns (uint256) {
                  if (to <= endBlock) {
                      return to - from;
                  } else if (from >= endBlock) {
                      return 0;
                  } else {
                      return endBlock - from;
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          interface IRewardConvertor {
              function convert(
                  address tokenToSell,
                  address tokenToBuy,
                  uint256 amount,
                  bytes calldata additionalData
              ) external returns (uint256);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import {IERC20} from '@openzeppelin/contracts/token/ERC20/IERC20.sol';
          interface IMintableERC20 is IERC20 {
              function SUPPLY_CAP() external view returns (uint256);
              function mint(address account, uint256 amount) external returns (bool);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          interface ITokenStaked {
              function getTotalStaked() external view returns (uint256);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev External interface of AccessControl declared to support ERC165 detection.
           */
          interface IAccessControl {
              /**
               * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
               *
               * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
               * {RoleAdminChanged} not being emitted signaling this.
               *
               * _Available since v3.1._
               */
              event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
              /**
               * @dev Emitted when `account` is granted `role`.
               *
               * `sender` is the account that originated the contract call, an admin role
               * bearer except when using {AccessControl-_setupRole}.
               */
              event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
              /**
               * @dev Emitted when `account` is revoked `role`.
               *
               * `sender` is the account that originated the contract call:
               *   - if using `revokeRole`, it is the admin role bearer
               *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
               */
              event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
              /**
               * @dev Returns `true` if `account` has been granted `role`.
               */
              function hasRole(bytes32 role, address account) external view returns (bool);
              /**
               * @dev Returns the admin role that controls `role`. See {grantRole} and
               * {revokeRole}.
               *
               * To change a role's admin, use {AccessControl-_setRoleAdmin}.
               */
              function getRoleAdmin(bytes32 role) external view returns (bytes32);
              /**
               * @dev Grants `role` to `account`.
               *
               * If `account` had not been already granted `role`, emits a {RoleGranted}
               * event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function grantRole(bytes32 role, address account) external;
              /**
               * @dev Revokes `role` from `account`.
               *
               * If `account` had been granted `role`, emits a {RoleRevoked} event.
               *
               * Requirements:
               *
               * - the caller must have ``role``'s admin role.
               */
              function revokeRole(bytes32 role, address account) external;
              /**
               * @dev Revokes `role` from the calling account.
               *
               * Roles are often managed via {grantRole} and {revokeRole}: this function's
               * purpose is to provide a mechanism for accounts to lose their privileges
               * if they are compromised (such as when a trusted device is misplaced).
               *
               * If the calling account had been granted `role`, emits a {RoleRevoked}
               * event.
               *
               * Requirements:
               *
               * - the caller must be `account`.
               */
              function renounceRole(bytes32 role, address account) external;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev String operations.
           */
          library Strings {
              bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
              /**
               * @dev Converts a `uint256` to its ASCII `string` decimal representation.
               */
              function toString(uint256 value) internal pure returns (string memory) {
                  // Inspired by OraclizeAPI's implementation - MIT licence
                  // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                  if (value == 0) {
                      return "0";
                  }
                  uint256 temp = value;
                  uint256 digits;
                  while (temp != 0) {
                      digits++;
                      temp /= 10;
                  }
                  bytes memory buffer = new bytes(digits);
                  while (value != 0) {
                      digits -= 1;
                      buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                      value /= 10;
                  }
                  return string(buffer);
              }
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
               */
              function toHexString(uint256 value) internal pure returns (string memory) {
                  if (value == 0) {
                      return "0x00";
                  }
                  uint256 temp = value;
                  uint256 length = 0;
                  while (temp != 0) {
                      length++;
                      temp >>= 8;
                  }
                  return toHexString(value, length);
              }
              /**
               * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
               */
              function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
                  bytes memory buffer = new bytes(2 * length + 2);
                  buffer[0] = "0";
                  buffer[1] = "x";
                  for (uint256 i = 2 * length + 1; i > 1; --i) {
                      buffer[i] = _HEX_SYMBOLS[value & 0xf];
                      value >>= 4;
                  }
                  require(value == 0, "Strings: hex length insufficient");
                  return string(buffer);
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
          pragma solidity ^0.8.0;
          import "./IERC165.sol";
          /**
           * @dev Implementation of the {IERC165} interface.
           *
           * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
           * for the additional interface id that will be supported. For example:
           *
           * ```solidity
           * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
           *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
           * }
           * ```
           *
           * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
           */
          abstract contract ERC165 is IERC165 {
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                  return interfaceId == type(IERC165).interfaceId;
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC165 standard, as defined in the
           * https://eips.ethereum.org/EIPS/eip-165[EIP].
           *
           * Implementers can declare support of contract interfaces, which can then be
           * queried by others ({ERC165Checker}).
           *
           * For an implementation, see {ERC165}.
           */
          interface IERC165 {
              /**
               * @dev Returns true if this contract implements the interface defined by
               * `interfaceId`. See the corresponding
               * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
               * to learn more about how these ids are created.
               *
               * This function call must use less than 30 000 gas.
               */
              function supportsInterface(bytes4 interfaceId) external view returns (bool);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          interface IStakeFor {
              function depositFor(address user, uint256 amount) external returns (bool);
          }