ETH Price: $1,974.25 (+0.29%)

Transaction Decoder

Block:
23305956 at Sep-06-2025 06:51:23 PM +UTC
Transaction Fee:
0.00034183614446982 ETH $0.67
Gas Used:
80,388 Gas / 4.252328015 Gwei

Emitted Events:

405 GnosisSafeProxy.0x75e41bc35ff1bf14d81d1d2f649c0084a0f974f9289c803ec9898eeec4c8d0b8( 0x75e41bc35ff1bf14d81d1d2f649c0084a0f974f9289c803ec9898eeec4c8d0b8, 00000000000000000000000041675c099f32341bf84bfc5382af534df5c7461a )
406 GnosisSafeProxy.0x5ac6c46c93c8d0e53714ba3b53db3e7c046da994313d7ed0d192028bc7c228b0( 0x5ac6c46c93c8d0e53714ba3b53db3e7c046da994313d7ed0d192028bc7c228b0, 0x000000000000000000000000fd0732dc9e303f09fcef3a7388ad10a83459ec99 )
407 GnosisSafeProxy.0x442e715f626346e8c54381002da614f62bee8d27386535b2521ec8540898556e( 0x442e715f626346e8c54381002da614f62bee8d27386535b2521ec8540898556e, 5a59152eab85546a535442defe921537a5bf55bc96b03fee12c66e3c12627f0d, 0000000000000000000000000000000000000000000000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
0x14B63Ed0...5A2407292
0.013595400353984137 Eth
Nonce: 18
0.013253564209514317 Eth
Nonce: 19
0.00034183614446982
(Titan Builder)
14.165823780850553923 Eth14.165941932797200195 Eth0.000118151946646272
0xFa80e55D...405573905

Execution Trace

GnosisSafeProxy.6a761202( )
  • GnosisSafe.execTransaction( to=0x526643F69b81B008F46d95CD5ced5eC0edFFDaC6, value=0, data=0xED007FC6, operation=1, safeTxGas=0, baseGas=0, gasPrice=0, gasToken=0x0000000000000000000000000000000000000000, refundReceiver=0x0000000000000000000000000000000000000000, signatures=0xC278E30BE93A73F145A1506C770F3A917AF5298DC5D06CEF457AE3CBA09AAE467C2F00F8D21CFE995E7CE00C83421BE125C25E14B111AEDD46408BCA00B5D60B1BBD7AC184EF0A61A7F0696D199B7D0661B5CF3C3B0ED27C3A22A36BAE00A9B34121272CC6EE7CDABA6E1E651DD6077C84D43A57BE4A5736DD8465B8FF46B249451B1DC4B7B36C8270B4BFC486F3D9AEC34A9712000BFC49C5F382DEFF64BFBE683C734B229578A92FCE3F46B7A53B5DB78F2273692180E17A4B571088E4ADDF047A1C ) => ( success=True )
    • Null: 0x000...001.5a59152e( )
    • Null: 0x000...001.5a59152e( )
    • Null: 0x000...001.5a59152e( )
    • SafeMigration.DELEGATECALL( )
      • GnosisSafeProxy.f08a0323( )
        • Safe.setFallbackHandler( handler=0xfd0732Dc9E303f09fCEf3a7388Ad10A83459Ec99 )
          File 1 of 4: GnosisSafeProxy
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          
          /// @title IProxy - Helper interface to access masterCopy of the Proxy on-chain
          /// @author Richard Meissner - <richard@gnosis.io>
          interface IProxy {
              function masterCopy() external view returns (address);
          }
          
          /// @title GnosisSafeProxy - Generic proxy contract allows to execute all transactions applying the code of a master contract.
          /// @author Stefan George - <stefan@gnosis.io>
          /// @author Richard Meissner - <richard@gnosis.io>
          contract GnosisSafeProxy {
              // singleton always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
              // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
              address internal singleton;
          
              /// @dev Constructor function sets address of singleton contract.
              /// @param _singleton Singleton address.
              constructor(address _singleton) {
                  require(_singleton != address(0), "Invalid singleton address provided");
                  singleton = _singleton;
              }
          
              /// @dev Fallback function forwards all transactions and returns all received return data.
              fallback() external payable {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let _singleton := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
                      // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
                      if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                          mstore(0, _singleton)
                          return(0, 0x20)
                      }
                      calldatacopy(0, 0, calldatasize())
                      let success := delegatecall(gas(), _singleton, 0, calldatasize(), 0, 0)
                      returndatacopy(0, 0, returndatasize())
                      if eq(success, 0) {
                          revert(0, returndatasize())
                      }
                      return(0, returndatasize())
                  }
              }
          }
          
          /// @title Proxy Factory - Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
          /// @author Stefan George - <stefan@gnosis.pm>
          contract GnosisSafeProxyFactory {
              event ProxyCreation(GnosisSafeProxy proxy, address singleton);
          
              /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
              /// @param singleton Address of singleton contract.
              /// @param data Payload for message call sent to new proxy contract.
              function createProxy(address singleton, bytes memory data) public returns (GnosisSafeProxy proxy) {
                  proxy = new GnosisSafeProxy(singleton);
                  if (data.length > 0)
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          if eq(call(gas(), proxy, 0, add(data, 0x20), mload(data), 0, 0), 0) {
                              revert(0, 0)
                          }
                      }
                  emit ProxyCreation(proxy, singleton);
              }
          
              /// @dev Allows to retrieve the runtime code of a deployed Proxy. This can be used to check that the expected Proxy was deployed.
              function proxyRuntimeCode() public pure returns (bytes memory) {
                  return type(GnosisSafeProxy).runtimeCode;
              }
          
              /// @dev Allows to retrieve the creation code used for the Proxy deployment. With this it is easily possible to calculate predicted address.
              function proxyCreationCode() public pure returns (bytes memory) {
                  return type(GnosisSafeProxy).creationCode;
              }
          
              /// @dev Allows to create new proxy contact using CREATE2 but it doesn't run the initializer.
              ///      This method is only meant as an utility to be called from other methods
              /// @param _singleton Address of singleton contract.
              /// @param initializer Payload for message call sent to new proxy contract.
              /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
              function deployProxyWithNonce(
                  address _singleton,
                  bytes memory initializer,
                  uint256 saltNonce
              ) internal returns (GnosisSafeProxy proxy) {
                  // If the initializer changes the proxy address should change too. Hashing the initializer data is cheaper than just concatinating it
                  bytes32 salt = keccak256(abi.encodePacked(keccak256(initializer), saltNonce));
                  bytes memory deploymentData = abi.encodePacked(type(GnosisSafeProxy).creationCode, uint256(uint160(_singleton)));
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      proxy := create2(0x0, add(0x20, deploymentData), mload(deploymentData), salt)
                  }
                  require(address(proxy) != address(0), "Create2 call failed");
              }
          
              /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
              /// @param _singleton Address of singleton contract.
              /// @param initializer Payload for message call sent to new proxy contract.
              /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
              function createProxyWithNonce(
                  address _singleton,
                  bytes memory initializer,
                  uint256 saltNonce
              ) public returns (GnosisSafeProxy proxy) {
                  proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                  if (initializer.length > 0)
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          if eq(call(gas(), proxy, 0, add(initializer, 0x20), mload(initializer), 0, 0), 0) {
                              revert(0, 0)
                          }
                      }
                  emit ProxyCreation(proxy, _singleton);
              }
          
              /// @dev Allows to create new proxy contact, execute a message call to the new proxy and call a specified callback within one transaction
              /// @param _singleton Address of singleton contract.
              /// @param initializer Payload for message call sent to new proxy contract.
              /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
              /// @param callback Callback that will be invoced after the new proxy contract has been successfully deployed and initialized.
              function createProxyWithCallback(
                  address _singleton,
                  bytes memory initializer,
                  uint256 saltNonce,
                  IProxyCreationCallback callback
              ) public returns (GnosisSafeProxy proxy) {
                  uint256 saltNonceWithCallback = uint256(keccak256(abi.encodePacked(saltNonce, callback)));
                  proxy = createProxyWithNonce(_singleton, initializer, saltNonceWithCallback);
                  if (address(callback) != address(0)) callback.proxyCreated(proxy, _singleton, initializer, saltNonce);
              }
          
              /// @dev Allows to get the address for a new proxy contact created via `createProxyWithNonce`
              ///      This method is only meant for address calculation purpose when you use an initializer that would revert,
              ///      therefore the response is returned with a revert. When calling this method set `from` to the address of the proxy factory.
              /// @param _singleton Address of singleton contract.
              /// @param initializer Payload for message call sent to new proxy contract.
              /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
              function calculateCreateProxyWithNonceAddress(
                  address _singleton,
                  bytes calldata initializer,
                  uint256 saltNonce
              ) external returns (GnosisSafeProxy proxy) {
                  proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                  revert(string(abi.encodePacked(proxy)));
              }
          }
          
          interface IProxyCreationCallback {
              function proxyCreated(
                  GnosisSafeProxy proxy,
                  address _singleton,
                  bytes calldata initializer,
                  uint256 saltNonce
              ) external;
          }

          File 2 of 4: GnosisSafe
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "./base/ModuleManager.sol";
          import "./base/OwnerManager.sol";
          import "./base/FallbackManager.sol";
          import "./base/GuardManager.sol";
          import "./common/EtherPaymentFallback.sol";
          import "./common/Singleton.sol";
          import "./common/SignatureDecoder.sol";
          import "./common/SecuredTokenTransfer.sol";
          import "./common/StorageAccessible.sol";
          import "./interfaces/ISignatureValidator.sol";
          import "./external/GnosisSafeMath.sol";
          /// @title Gnosis Safe - A multisignature wallet with support for confirmations using signed messages based on ERC191.
          /// @author Stefan George - <stefan@gnosis.io>
          /// @author Richard Meissner - <richard@gnosis.io>
          contract GnosisSafe is
              EtherPaymentFallback,
              Singleton,
              ModuleManager,
              OwnerManager,
              SignatureDecoder,
              SecuredTokenTransfer,
              ISignatureValidatorConstants,
              FallbackManager,
              StorageAccessible,
              GuardManager
          {
              using GnosisSafeMath for uint256;
              string public constant VERSION = "1.3.0";
              // keccak256(
              //     "EIP712Domain(uint256 chainId,address verifyingContract)"
              // );
              bytes32 private constant DOMAIN_SEPARATOR_TYPEHASH = 0x47e79534a245952e8b16893a336b85a3d9ea9fa8c573f3d803afb92a79469218;
              // keccak256(
              //     "SafeTx(address to,uint256 value,bytes data,uint8 operation,uint256 safeTxGas,uint256 baseGas,uint256 gasPrice,address gasToken,address refundReceiver,uint256 nonce)"
              // );
              bytes32 private constant SAFE_TX_TYPEHASH = 0xbb8310d486368db6bd6f849402fdd73ad53d316b5a4b2644ad6efe0f941286d8;
              event SafeSetup(address indexed initiator, address[] owners, uint256 threshold, address initializer, address fallbackHandler);
              event ApproveHash(bytes32 indexed approvedHash, address indexed owner);
              event SignMsg(bytes32 indexed msgHash);
              event ExecutionFailure(bytes32 txHash, uint256 payment);
              event ExecutionSuccess(bytes32 txHash, uint256 payment);
              uint256 public nonce;
              bytes32 private _deprecatedDomainSeparator;
              // Mapping to keep track of all message hashes that have been approve by ALL REQUIRED owners
              mapping(bytes32 => uint256) public signedMessages;
              // Mapping to keep track of all hashes (message or transaction) that have been approve by ANY owners
              mapping(address => mapping(bytes32 => uint256)) public approvedHashes;
              // This constructor ensures that this contract can only be used as a master copy for Proxy contracts
              constructor() {
                  // By setting the threshold it is not possible to call setup anymore,
                  // so we create a Safe with 0 owners and threshold 1.
                  // This is an unusable Safe, perfect for the singleton
                  threshold = 1;
              }
              /// @dev Setup function sets initial storage of contract.
              /// @param _owners List of Safe owners.
              /// @param _threshold Number of required confirmations for a Safe transaction.
              /// @param to Contract address for optional delegate call.
              /// @param data Data payload for optional delegate call.
              /// @param fallbackHandler Handler for fallback calls to this contract
              /// @param paymentToken Token that should be used for the payment (0 is ETH)
              /// @param payment Value that should be paid
              /// @param paymentReceiver Adddress that should receive the payment (or 0 if tx.origin)
              function setup(
                  address[] calldata _owners,
                  uint256 _threshold,
                  address to,
                  bytes calldata data,
                  address fallbackHandler,
                  address paymentToken,
                  uint256 payment,
                  address payable paymentReceiver
              ) external {
                  // setupOwners checks if the Threshold is already set, therefore preventing that this method is called twice
                  setupOwners(_owners, _threshold);
                  if (fallbackHandler != address(0)) internalSetFallbackHandler(fallbackHandler);
                  // As setupOwners can only be called if the contract has not been initialized we don't need a check for setupModules
                  setupModules(to, data);
                  if (payment > 0) {
                      // To avoid running into issues with EIP-170 we reuse the handlePayment function (to avoid adjusting code of that has been verified we do not adjust the method itself)
                      // baseGas = 0, gasPrice = 1 and gas = payment => amount = (payment + 0) * 1 = payment
                      handlePayment(payment, 0, 1, paymentToken, paymentReceiver);
                  }
                  emit SafeSetup(msg.sender, _owners, _threshold, to, fallbackHandler);
              }
              /// @dev Allows to execute a Safe transaction confirmed by required number of owners and then pays the account that submitted the transaction.
              ///      Note: The fees are always transferred, even if the user transaction fails.
              /// @param to Destination address of Safe transaction.
              /// @param value Ether value of Safe transaction.
              /// @param data Data payload of Safe transaction.
              /// @param operation Operation type of Safe transaction.
              /// @param safeTxGas Gas that should be used for the Safe transaction.
              /// @param baseGas Gas costs that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
              /// @param gasPrice Gas price that should be used for the payment calculation.
              /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
              /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
              /// @param signatures Packed signature data ({bytes32 r}{bytes32 s}{uint8 v})
              function execTransaction(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address payable refundReceiver,
                  bytes memory signatures
              ) public payable virtual returns (bool success) {
                  bytes32 txHash;
                  // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                  {
                      bytes memory txHashData =
                          encodeTransactionData(
                              // Transaction info
                              to,
                              value,
                              data,
                              operation,
                              safeTxGas,
                              // Payment info
                              baseGas,
                              gasPrice,
                              gasToken,
                              refundReceiver,
                              // Signature info
                              nonce
                          );
                      // Increase nonce and execute transaction.
                      nonce++;
                      txHash = keccak256(txHashData);
                      checkSignatures(txHash, txHashData, signatures);
                  }
                  address guard = getGuard();
                  {
                      if (guard != address(0)) {
                          Guard(guard).checkTransaction(
                              // Transaction info
                              to,
                              value,
                              data,
                              operation,
                              safeTxGas,
                              // Payment info
                              baseGas,
                              gasPrice,
                              gasToken,
                              refundReceiver,
                              // Signature info
                              signatures,
                              msg.sender
                          );
                      }
                  }
                  // We require some gas to emit the events (at least 2500) after the execution and some to perform code until the execution (500)
                  // We also include the 1/64 in the check that is not send along with a call to counteract potential shortings because of EIP-150
                  require(gasleft() >= ((safeTxGas * 64) / 63).max(safeTxGas + 2500) + 500, "GS010");
                  // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                  {
                      uint256 gasUsed = gasleft();
                      // If the gasPrice is 0 we assume that nearly all available gas can be used (it is always more than safeTxGas)
                      // We only substract 2500 (compared to the 3000 before) to ensure that the amount passed is still higher than safeTxGas
                      success = execute(to, value, data, operation, gasPrice == 0 ? (gasleft() - 2500) : safeTxGas);
                      gasUsed = gasUsed.sub(gasleft());
                      // If no safeTxGas and no gasPrice was set (e.g. both are 0), then the internal tx is required to be successful
                      // This makes it possible to use `estimateGas` without issues, as it searches for the minimum gas where the tx doesn't revert
                      require(success || safeTxGas != 0 || gasPrice != 0, "GS013");
                      // We transfer the calculated tx costs to the tx.origin to avoid sending it to intermediate contracts that have made calls
                      uint256 payment = 0;
                      if (gasPrice > 0) {
                          payment = handlePayment(gasUsed, baseGas, gasPrice, gasToken, refundReceiver);
                      }
                      if (success) emit ExecutionSuccess(txHash, payment);
                      else emit ExecutionFailure(txHash, payment);
                  }
                  {
                      if (guard != address(0)) {
                          Guard(guard).checkAfterExecution(txHash, success);
                      }
                  }
              }
              function handlePayment(
                  uint256 gasUsed,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address payable refundReceiver
              ) private returns (uint256 payment) {
                  // solhint-disable-next-line avoid-tx-origin
                  address payable receiver = refundReceiver == address(0) ? payable(tx.origin) : refundReceiver;
                  if (gasToken == address(0)) {
                      // For ETH we will only adjust the gas price to not be higher than the actual used gas price
                      payment = gasUsed.add(baseGas).mul(gasPrice < tx.gasprice ? gasPrice : tx.gasprice);
                      require(receiver.send(payment), "GS011");
                  } else {
                      payment = gasUsed.add(baseGas).mul(gasPrice);
                      require(transferToken(gasToken, receiver, payment), "GS012");
                  }
              }
              /**
               * @dev Checks whether the signature provided is valid for the provided data, hash. Will revert otherwise.
               * @param dataHash Hash of the data (could be either a message hash or transaction hash)
               * @param data That should be signed (this is passed to an external validator contract)
               * @param signatures Signature data that should be verified. Can be ECDSA signature, contract signature (EIP-1271) or approved hash.
               */
              function checkSignatures(
                  bytes32 dataHash,
                  bytes memory data,
                  bytes memory signatures
              ) public view {
                  // Load threshold to avoid multiple storage loads
                  uint256 _threshold = threshold;
                  // Check that a threshold is set
                  require(_threshold > 0, "GS001");
                  checkNSignatures(dataHash, data, signatures, _threshold);
              }
              /**
               * @dev Checks whether the signature provided is valid for the provided data, hash. Will revert otherwise.
               * @param dataHash Hash of the data (could be either a message hash or transaction hash)
               * @param data That should be signed (this is passed to an external validator contract)
               * @param signatures Signature data that should be verified. Can be ECDSA signature, contract signature (EIP-1271) or approved hash.
               * @param requiredSignatures Amount of required valid signatures.
               */
              function checkNSignatures(
                  bytes32 dataHash,
                  bytes memory data,
                  bytes memory signatures,
                  uint256 requiredSignatures
              ) public view {
                  // Check that the provided signature data is not too short
                  require(signatures.length >= requiredSignatures.mul(65), "GS020");
                  // There cannot be an owner with address 0.
                  address lastOwner = address(0);
                  address currentOwner;
                  uint8 v;
                  bytes32 r;
                  bytes32 s;
                  uint256 i;
                  for (i = 0; i < requiredSignatures; i++) {
                      (v, r, s) = signatureSplit(signatures, i);
                      if (v == 0) {
                          // If v is 0 then it is a contract signature
                          // When handling contract signatures the address of the contract is encoded into r
                          currentOwner = address(uint160(uint256(r)));
                          // Check that signature data pointer (s) is not pointing inside the static part of the signatures bytes
                          // This check is not completely accurate, since it is possible that more signatures than the threshold are send.
                          // Here we only check that the pointer is not pointing inside the part that is being processed
                          require(uint256(s) >= requiredSignatures.mul(65), "GS021");
                          // Check that signature data pointer (s) is in bounds (points to the length of data -> 32 bytes)
                          require(uint256(s).add(32) <= signatures.length, "GS022");
                          // Check if the contract signature is in bounds: start of data is s + 32 and end is start + signature length
                          uint256 contractSignatureLen;
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              contractSignatureLen := mload(add(add(signatures, s), 0x20))
                          }
                          require(uint256(s).add(32).add(contractSignatureLen) <= signatures.length, "GS023");
                          // Check signature
                          bytes memory contractSignature;
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              // The signature data for contract signatures is appended to the concatenated signatures and the offset is stored in s
                              contractSignature := add(add(signatures, s), 0x20)
                          }
                          require(ISignatureValidator(currentOwner).isValidSignature(data, contractSignature) == EIP1271_MAGIC_VALUE, "GS024");
                      } else if (v == 1) {
                          // If v is 1 then it is an approved hash
                          // When handling approved hashes the address of the approver is encoded into r
                          currentOwner = address(uint160(uint256(r)));
                          // Hashes are automatically approved by the sender of the message or when they have been pre-approved via a separate transaction
                          require(msg.sender == currentOwner || approvedHashes[currentOwner][dataHash] != 0, "GS025");
                      } else if (v > 30) {
                          // If v > 30 then default va (27,28) has been adjusted for eth_sign flow
                          // To support eth_sign and similar we adjust v and hash the messageHash with the Ethereum message prefix before applying ecrecover
                          currentOwner = ecrecover(keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
          32", dataHash)), v - 4, r, s);
                      } else {
                          // Default is the ecrecover flow with the provided data hash
                          // Use ecrecover with the messageHash for EOA signatures
                          currentOwner = ecrecover(dataHash, v, r, s);
                      }
                      require(currentOwner > lastOwner && owners[currentOwner] != address(0) && currentOwner != SENTINEL_OWNERS, "GS026");
                      lastOwner = currentOwner;
                  }
              }
              /// @dev Allows to estimate a Safe transaction.
              ///      This method is only meant for estimation purpose, therefore the call will always revert and encode the result in the revert data.
              ///      Since the `estimateGas` function includes refunds, call this method to get an estimated of the costs that are deducted from the safe with `execTransaction`
              /// @param to Destination address of Safe transaction.
              /// @param value Ether value of Safe transaction.
              /// @param data Data payload of Safe transaction.
              /// @param operation Operation type of Safe transaction.
              /// @return Estimate without refunds and overhead fees (base transaction and payload data gas costs).
              /// @notice Deprecated in favor of common/StorageAccessible.sol and will be removed in next version.
              function requiredTxGas(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation
              ) external returns (uint256) {
                  uint256 startGas = gasleft();
                  // We don't provide an error message here, as we use it to return the estimate
                  require(execute(to, value, data, operation, gasleft()));
                  uint256 requiredGas = startGas - gasleft();
                  // Convert response to string and return via error message
                  revert(string(abi.encodePacked(requiredGas)));
              }
              /**
               * @dev Marks a hash as approved. This can be used to validate a hash that is used by a signature.
               * @param hashToApprove The hash that should be marked as approved for signatures that are verified by this contract.
               */
              function approveHash(bytes32 hashToApprove) external {
                  require(owners[msg.sender] != address(0), "GS030");
                  approvedHashes[msg.sender][hashToApprove] = 1;
                  emit ApproveHash(hashToApprove, msg.sender);
              }
              /// @dev Returns the chain id used by this contract.
              function getChainId() public view returns (uint256) {
                  uint256 id;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      id := chainid()
                  }
                  return id;
              }
              function domainSeparator() public view returns (bytes32) {
                  return keccak256(abi.encode(DOMAIN_SEPARATOR_TYPEHASH, getChainId(), this));
              }
              /// @dev Returns the bytes that are hashed to be signed by owners.
              /// @param to Destination address.
              /// @param value Ether value.
              /// @param data Data payload.
              /// @param operation Operation type.
              /// @param safeTxGas Gas that should be used for the safe transaction.
              /// @param baseGas Gas costs for that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
              /// @param gasPrice Maximum gas price that should be used for this transaction.
              /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
              /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
              /// @param _nonce Transaction nonce.
              /// @return Transaction hash bytes.
              function encodeTransactionData(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address refundReceiver,
                  uint256 _nonce
              ) public view returns (bytes memory) {
                  bytes32 safeTxHash =
                      keccak256(
                          abi.encode(
                              SAFE_TX_TYPEHASH,
                              to,
                              value,
                              keccak256(data),
                              operation,
                              safeTxGas,
                              baseGas,
                              gasPrice,
                              gasToken,
                              refundReceiver,
                              _nonce
                          )
                      );
                  return abi.encodePacked(bytes1(0x19), bytes1(0x01), domainSeparator(), safeTxHash);
              }
              /// @dev Returns hash to be signed by owners.
              /// @param to Destination address.
              /// @param value Ether value.
              /// @param data Data payload.
              /// @param operation Operation type.
              /// @param safeTxGas Fas that should be used for the safe transaction.
              /// @param baseGas Gas costs for data used to trigger the safe transaction.
              /// @param gasPrice Maximum gas price that should be used for this transaction.
              /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
              /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
              /// @param _nonce Transaction nonce.
              /// @return Transaction hash.
              function getTransactionHash(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address refundReceiver,
                  uint256 _nonce
              ) public view returns (bytes32) {
                  return keccak256(encodeTransactionData(to, value, data, operation, safeTxGas, baseGas, gasPrice, gasToken, refundReceiver, _nonce));
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/Enum.sol";
          /// @title Executor - A contract that can execute transactions
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract Executor {
              function execute(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation,
                  uint256 txGas
              ) internal returns (bool success) {
                  if (operation == Enum.Operation.DelegateCall) {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          success := delegatecall(txGas, to, add(data, 0x20), mload(data), 0, 0)
                      }
                  } else {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          success := call(txGas, to, value, add(data, 0x20), mload(data), 0, 0)
                      }
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/SelfAuthorized.sol";
          /// @title Fallback Manager - A contract that manages fallback calls made to this contract
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract FallbackManager is SelfAuthorized {
              event ChangedFallbackHandler(address handler);
              // keccak256("fallback_manager.handler.address")
              bytes32 internal constant FALLBACK_HANDLER_STORAGE_SLOT = 0x6c9a6c4a39284e37ed1cf53d337577d14212a4870fb976a4366c693b939918d5;
              function internalSetFallbackHandler(address handler) internal {
                  bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      sstore(slot, handler)
                  }
              }
              /// @dev Allows to add a contract to handle fallback calls.
              ///      Only fallback calls without value and with data will be forwarded.
              ///      This can only be done via a Safe transaction.
              /// @param handler contract to handle fallbacks calls.
              function setFallbackHandler(address handler) public authorized {
                  internalSetFallbackHandler(handler);
                  emit ChangedFallbackHandler(handler);
              }
              // solhint-disable-next-line payable-fallback,no-complex-fallback
              fallback() external {
                  bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let handler := sload(slot)
                      if iszero(handler) {
                          return(0, 0)
                      }
                      calldatacopy(0, 0, calldatasize())
                      // The msg.sender address is shifted to the left by 12 bytes to remove the padding
                      // Then the address without padding is stored right after the calldata
                      mstore(calldatasize(), shl(96, caller()))
                      // Add 20 bytes for the address appended add the end
                      let success := call(gas(), handler, 0, 0, add(calldatasize(), 20), 0, 0)
                      returndatacopy(0, 0, returndatasize())
                      if iszero(success) {
                          revert(0, returndatasize())
                      }
                      return(0, returndatasize())
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/Enum.sol";
          import "../common/SelfAuthorized.sol";
          interface Guard {
              function checkTransaction(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address payable refundReceiver,
                  bytes memory signatures,
                  address msgSender
              ) external;
              function checkAfterExecution(bytes32 txHash, bool success) external;
          }
          /// @title Fallback Manager - A contract that manages fallback calls made to this contract
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract GuardManager is SelfAuthorized {
              event ChangedGuard(address guard);
              // keccak256("guard_manager.guard.address")
              bytes32 internal constant GUARD_STORAGE_SLOT = 0x4a204f620c8c5ccdca3fd54d003badd85ba500436a431f0cbda4f558c93c34c8;
              /// @dev Set a guard that checks transactions before execution
              /// @param guard The address of the guard to be used or the 0 address to disable the guard
              function setGuard(address guard) external authorized {
                  bytes32 slot = GUARD_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      sstore(slot, guard)
                  }
                  emit ChangedGuard(guard);
              }
              function getGuard() internal view returns (address guard) {
                  bytes32 slot = GUARD_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      guard := sload(slot)
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/Enum.sol";
          import "../common/SelfAuthorized.sol";
          import "./Executor.sol";
          /// @title Module Manager - A contract that manages modules that can execute transactions via this contract
          /// @author Stefan George - <stefan@gnosis.pm>
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract ModuleManager is SelfAuthorized, Executor {
              event EnabledModule(address module);
              event DisabledModule(address module);
              event ExecutionFromModuleSuccess(address indexed module);
              event ExecutionFromModuleFailure(address indexed module);
              address internal constant SENTINEL_MODULES = address(0x1);
              mapping(address => address) internal modules;
              function setupModules(address to, bytes memory data) internal {
                  require(modules[SENTINEL_MODULES] == address(0), "GS100");
                  modules[SENTINEL_MODULES] = SENTINEL_MODULES;
                  if (to != address(0))
                      // Setup has to complete successfully or transaction fails.
                      require(execute(to, 0, data, Enum.Operation.DelegateCall, gasleft()), "GS000");
              }
              /// @dev Allows to add a module to the whitelist.
              ///      This can only be done via a Safe transaction.
              /// @notice Enables the module `module` for the Safe.
              /// @param module Module to be whitelisted.
              function enableModule(address module) public authorized {
                  // Module address cannot be null or sentinel.
                  require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                  // Module cannot be added twice.
                  require(modules[module] == address(0), "GS102");
                  modules[module] = modules[SENTINEL_MODULES];
                  modules[SENTINEL_MODULES] = module;
                  emit EnabledModule(module);
              }
              /// @dev Allows to remove a module from the whitelist.
              ///      This can only be done via a Safe transaction.
              /// @notice Disables the module `module` for the Safe.
              /// @param prevModule Module that pointed to the module to be removed in the linked list
              /// @param module Module to be removed.
              function disableModule(address prevModule, address module) public authorized {
                  // Validate module address and check that it corresponds to module index.
                  require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                  require(modules[prevModule] == module, "GS103");
                  modules[prevModule] = modules[module];
                  modules[module] = address(0);
                  emit DisabledModule(module);
              }
              /// @dev Allows a Module to execute a Safe transaction without any further confirmations.
              /// @param to Destination address of module transaction.
              /// @param value Ether value of module transaction.
              /// @param data Data payload of module transaction.
              /// @param operation Operation type of module transaction.
              function execTransactionFromModule(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation
              ) public virtual returns (bool success) {
                  // Only whitelisted modules are allowed.
                  require(msg.sender != SENTINEL_MODULES && modules[msg.sender] != address(0), "GS104");
                  // Execute transaction without further confirmations.
                  success = execute(to, value, data, operation, gasleft());
                  if (success) emit ExecutionFromModuleSuccess(msg.sender);
                  else emit ExecutionFromModuleFailure(msg.sender);
              }
              /// @dev Allows a Module to execute a Safe transaction without any further confirmations and return data
              /// @param to Destination address of module transaction.
              /// @param value Ether value of module transaction.
              /// @param data Data payload of module transaction.
              /// @param operation Operation type of module transaction.
              function execTransactionFromModuleReturnData(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation
              ) public returns (bool success, bytes memory returnData) {
                  success = execTransactionFromModule(to, value, data, operation);
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // Load free memory location
                      let ptr := mload(0x40)
                      // We allocate memory for the return data by setting the free memory location to
                      // current free memory location + data size + 32 bytes for data size value
                      mstore(0x40, add(ptr, add(returndatasize(), 0x20)))
                      // Store the size
                      mstore(ptr, returndatasize())
                      // Store the data
                      returndatacopy(add(ptr, 0x20), 0, returndatasize())
                      // Point the return data to the correct memory location
                      returnData := ptr
                  }
              }
              /// @dev Returns if an module is enabled
              /// @return True if the module is enabled
              function isModuleEnabled(address module) public view returns (bool) {
                  return SENTINEL_MODULES != module && modules[module] != address(0);
              }
              /// @dev Returns array of modules.
              /// @param start Start of the page.
              /// @param pageSize Maximum number of modules that should be returned.
              /// @return array Array of modules.
              /// @return next Start of the next page.
              function getModulesPaginated(address start, uint256 pageSize) external view returns (address[] memory array, address next) {
                  // Init array with max page size
                  array = new address[](pageSize);
                  // Populate return array
                  uint256 moduleCount = 0;
                  address currentModule = modules[start];
                  while (currentModule != address(0x0) && currentModule != SENTINEL_MODULES && moduleCount < pageSize) {
                      array[moduleCount] = currentModule;
                      currentModule = modules[currentModule];
                      moduleCount++;
                  }
                  next = currentModule;
                  // Set correct size of returned array
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      mstore(array, moduleCount)
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/SelfAuthorized.sol";
          /// @title OwnerManager - Manages a set of owners and a threshold to perform actions.
          /// @author Stefan George - <stefan@gnosis.pm>
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract OwnerManager is SelfAuthorized {
              event AddedOwner(address owner);
              event RemovedOwner(address owner);
              event ChangedThreshold(uint256 threshold);
              address internal constant SENTINEL_OWNERS = address(0x1);
              mapping(address => address) internal owners;
              uint256 internal ownerCount;
              uint256 internal threshold;
              /// @dev Setup function sets initial storage of contract.
              /// @param _owners List of Safe owners.
              /// @param _threshold Number of required confirmations for a Safe transaction.
              function setupOwners(address[] memory _owners, uint256 _threshold) internal {
                  // Threshold can only be 0 at initialization.
                  // Check ensures that setup function can only be called once.
                  require(threshold == 0, "GS200");
                  // Validate that threshold is smaller than number of added owners.
                  require(_threshold <= _owners.length, "GS201");
                  // There has to be at least one Safe owner.
                  require(_threshold >= 1, "GS202");
                  // Initializing Safe owners.
                  address currentOwner = SENTINEL_OWNERS;
                  for (uint256 i = 0; i < _owners.length; i++) {
                      // Owner address cannot be null.
                      address owner = _owners[i];
                      require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this) && currentOwner != owner, "GS203");
                      // No duplicate owners allowed.
                      require(owners[owner] == address(0), "GS204");
                      owners[currentOwner] = owner;
                      currentOwner = owner;
                  }
                  owners[currentOwner] = SENTINEL_OWNERS;
                  ownerCount = _owners.length;
                  threshold = _threshold;
              }
              /// @dev Allows to add a new owner to the Safe and update the threshold at the same time.
              ///      This can only be done via a Safe transaction.
              /// @notice Adds the owner `owner` to the Safe and updates the threshold to `_threshold`.
              /// @param owner New owner address.
              /// @param _threshold New threshold.
              function addOwnerWithThreshold(address owner, uint256 _threshold) public authorized {
                  // Owner address cannot be null, the sentinel or the Safe itself.
                  require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this), "GS203");
                  // No duplicate owners allowed.
                  require(owners[owner] == address(0), "GS204");
                  owners[owner] = owners[SENTINEL_OWNERS];
                  owners[SENTINEL_OWNERS] = owner;
                  ownerCount++;
                  emit AddedOwner(owner);
                  // Change threshold if threshold was changed.
                  if (threshold != _threshold) changeThreshold(_threshold);
              }
              /// @dev Allows to remove an owner from the Safe and update the threshold at the same time.
              ///      This can only be done via a Safe transaction.
              /// @notice Removes the owner `owner` from the Safe and updates the threshold to `_threshold`.
              /// @param prevOwner Owner that pointed to the owner to be removed in the linked list
              /// @param owner Owner address to be removed.
              /// @param _threshold New threshold.
              function removeOwner(
                  address prevOwner,
                  address owner,
                  uint256 _threshold
              ) public authorized {
                  // Only allow to remove an owner, if threshold can still be reached.
                  require(ownerCount - 1 >= _threshold, "GS201");
                  // Validate owner address and check that it corresponds to owner index.
                  require(owner != address(0) && owner != SENTINEL_OWNERS, "GS203");
                  require(owners[prevOwner] == owner, "GS205");
                  owners[prevOwner] = owners[owner];
                  owners[owner] = address(0);
                  ownerCount--;
                  emit RemovedOwner(owner);
                  // Change threshold if threshold was changed.
                  if (threshold != _threshold) changeThreshold(_threshold);
              }
              /// @dev Allows to swap/replace an owner from the Safe with another address.
              ///      This can only be done via a Safe transaction.
              /// @notice Replaces the owner `oldOwner` in the Safe with `newOwner`.
              /// @param prevOwner Owner that pointed to the owner to be replaced in the linked list
              /// @param oldOwner Owner address to be replaced.
              /// @param newOwner New owner address.
              function swapOwner(
                  address prevOwner,
                  address oldOwner,
                  address newOwner
              ) public authorized {
                  // Owner address cannot be null, the sentinel or the Safe itself.
                  require(newOwner != address(0) && newOwner != SENTINEL_OWNERS && newOwner != address(this), "GS203");
                  // No duplicate owners allowed.
                  require(owners[newOwner] == address(0), "GS204");
                  // Validate oldOwner address and check that it corresponds to owner index.
                  require(oldOwner != address(0) && oldOwner != SENTINEL_OWNERS, "GS203");
                  require(owners[prevOwner] == oldOwner, "GS205");
                  owners[newOwner] = owners[oldOwner];
                  owners[prevOwner] = newOwner;
                  owners[oldOwner] = address(0);
                  emit RemovedOwner(oldOwner);
                  emit AddedOwner(newOwner);
              }
              /// @dev Allows to update the number of required confirmations by Safe owners.
              ///      This can only be done via a Safe transaction.
              /// @notice Changes the threshold of the Safe to `_threshold`.
              /// @param _threshold New threshold.
              function changeThreshold(uint256 _threshold) public authorized {
                  // Validate that threshold is smaller than number of owners.
                  require(_threshold <= ownerCount, "GS201");
                  // There has to be at least one Safe owner.
                  require(_threshold >= 1, "GS202");
                  threshold = _threshold;
                  emit ChangedThreshold(threshold);
              }
              function getThreshold() public view returns (uint256) {
                  return threshold;
              }
              function isOwner(address owner) public view returns (bool) {
                  return owner != SENTINEL_OWNERS && owners[owner] != address(0);
              }
              /// @dev Returns array of owners.
              /// @return Array of Safe owners.
              function getOwners() public view returns (address[] memory) {
                  address[] memory array = new address[](ownerCount);
                  // populate return array
                  uint256 index = 0;
                  address currentOwner = owners[SENTINEL_OWNERS];
                  while (currentOwner != SENTINEL_OWNERS) {
                      array[index] = currentOwner;
                      currentOwner = owners[currentOwner];
                      index++;
                  }
                  return array;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title Enum - Collection of enums
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract Enum {
              enum Operation {Call, DelegateCall}
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title EtherPaymentFallback - A contract that has a fallback to accept ether payments
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract EtherPaymentFallback {
              event SafeReceived(address indexed sender, uint256 value);
              /// @dev Fallback function accepts Ether transactions.
              receive() external payable {
                  emit SafeReceived(msg.sender, msg.value);
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title SecuredTokenTransfer - Secure token transfer
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract SecuredTokenTransfer {
              /// @dev Transfers a token and returns if it was a success
              /// @param token Token that should be transferred
              /// @param receiver Receiver to whom the token should be transferred
              /// @param amount The amount of tokens that should be transferred
              function transferToken(
                  address token,
                  address receiver,
                  uint256 amount
              ) internal returns (bool transferred) {
                  // 0xa9059cbb - keccack("transfer(address,uint256)")
                  bytes memory data = abi.encodeWithSelector(0xa9059cbb, receiver, amount);
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // We write the return value to scratch space.
                      // See https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory
                      let success := call(sub(gas(), 10000), token, 0, add(data, 0x20), mload(data), 0, 0x20)
                      switch returndatasize()
                          case 0 {
                              transferred := success
                          }
                          case 0x20 {
                              transferred := iszero(or(iszero(success), iszero(mload(0))))
                          }
                          default {
                              transferred := 0
                          }
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title SelfAuthorized - authorizes current contract to perform actions
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract SelfAuthorized {
              function requireSelfCall() private view {
                  require(msg.sender == address(this), "GS031");
              }
              modifier authorized() {
                  // This is a function call as it minimized the bytecode size
                  requireSelfCall();
                  _;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title SignatureDecoder - Decodes signatures that a encoded as bytes
          /// @author Richard Meissner - <richard@gnosis.pm>
          contract SignatureDecoder {
              /// @dev divides bytes signature into `uint8 v, bytes32 r, bytes32 s`.
              /// @notice Make sure to peform a bounds check for @param pos, to avoid out of bounds access on @param signatures
              /// @param pos which signature to read. A prior bounds check of this parameter should be performed, to avoid out of bounds access
              /// @param signatures concatenated rsv signatures
              function signatureSplit(bytes memory signatures, uint256 pos)
                  internal
                  pure
                  returns (
                      uint8 v,
                      bytes32 r,
                      bytes32 s
                  )
              {
                  // The signature format is a compact form of:
                  //   {bytes32 r}{bytes32 s}{uint8 v}
                  // Compact means, uint8 is not padded to 32 bytes.
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let signaturePos := mul(0x41, pos)
                      r := mload(add(signatures, add(signaturePos, 0x20)))
                      s := mload(add(signatures, add(signaturePos, 0x40)))
                      // Here we are loading the last 32 bytes, including 31 bytes
                      // of 's'. There is no 'mload8' to do this.
                      //
                      // 'byte' is not working due to the Solidity parser, so lets
                      // use the second best option, 'and'
                      v := and(mload(add(signatures, add(signaturePos, 0x41))), 0xff)
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title Singleton - Base for singleton contracts (should always be first super contract)
          ///         This contract is tightly coupled to our proxy contract (see `proxies/GnosisSafeProxy.sol`)
          /// @author Richard Meissner - <richard@gnosis.io>
          contract Singleton {
              // singleton always needs to be first declared variable, to ensure that it is at the same location as in the Proxy contract.
              // It should also always be ensured that the address is stored alone (uses a full word)
              address private singleton;
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @title StorageAccessible - generic base contract that allows callers to access all internal storage.
          /// @notice See https://github.com/gnosis/util-contracts/blob/bb5fe5fb5df6d8400998094fb1b32a178a47c3a1/contracts/StorageAccessible.sol
          contract StorageAccessible {
              /**
               * @dev Reads `length` bytes of storage in the currents contract
               * @param offset - the offset in the current contract's storage in words to start reading from
               * @param length - the number of words (32 bytes) of data to read
               * @return the bytes that were read.
               */
              function getStorageAt(uint256 offset, uint256 length) public view returns (bytes memory) {
                  bytes memory result = new bytes(length * 32);
                  for (uint256 index = 0; index < length; index++) {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let word := sload(add(offset, index))
                          mstore(add(add(result, 0x20), mul(index, 0x20)), word)
                      }
                  }
                  return result;
              }
              /**
               * @dev Performs a delegetecall on a targetContract in the context of self.
               * Internally reverts execution to avoid side effects (making it static).
               *
               * This method reverts with data equal to `abi.encode(bool(success), bytes(response))`.
               * Specifically, the `returndata` after a call to this method will be:
               * `success:bool || response.length:uint256 || response:bytes`.
               *
               * @param targetContract Address of the contract containing the code to execute.
               * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
               */
              function simulateAndRevert(address targetContract, bytes memory calldataPayload) external {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let success := delegatecall(gas(), targetContract, add(calldataPayload, 0x20), mload(calldataPayload), 0, 0)
                      mstore(0x00, success)
                      mstore(0x20, returndatasize())
                      returndatacopy(0x40, 0, returndatasize())
                      revert(0, add(returndatasize(), 0x40))
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title GnosisSafeMath
           * @dev Math operations with safety checks that revert on error
           * Renamed from SafeMath to GnosisSafeMath to avoid conflicts
           * TODO: remove once open zeppelin update to solc 0.5.0
           */
          library GnosisSafeMath {
              /**
               * @dev Multiplies two numbers, reverts on overflow.
               */
              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                  // benefit is lost if 'b' is also tested.
                  // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
                  if (a == 0) {
                      return 0;
                  }
                  uint256 c = a * b;
                  require(c / a == b);
                  return c;
              }
              /**
               * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
               */
              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                  require(b <= a);
                  uint256 c = a - b;
                  return c;
              }
              /**
               * @dev Adds two numbers, reverts on overflow.
               */
              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                  uint256 c = a + b;
                  require(c >= a);
                  return c;
              }
              /**
               * @dev Returns the largest of two numbers.
               */
              function max(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a >= b ? a : b;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          contract ISignatureValidatorConstants {
              // bytes4(keccak256("isValidSignature(bytes,bytes)")
              bytes4 internal constant EIP1271_MAGIC_VALUE = 0x20c13b0b;
          }
          abstract contract ISignatureValidator is ISignatureValidatorConstants {
              /**
               * @dev Should return whether the signature provided is valid for the provided data
               * @param _data Arbitrary length data signed on the behalf of address(this)
               * @param _signature Signature byte array associated with _data
               *
               * MUST return the bytes4 magic value 0x20c13b0b when function passes.
               * MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5)
               * MUST allow external calls
               */
              function isValidSignature(bytes memory _data, bytes memory _signature) public view virtual returns (bytes4);
          }
          

          File 3 of 4: SafeMigration
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import {SafeStorage} from "../libraries/SafeStorage.sol";
          interface ISafe {
              function setFallbackHandler(address handler) external;
          }
          /**
           * @title Migration Contract for Safe Upgrade
           * @notice This is a generic contract that facilitates Safe and SafeL2 proxy contracts to migrate their singleton address.
           *         The supported target Safe version is immutable and set in the constructor during the deployment of the contract.
           *         This contract also supports migration with fallback handler update.
           * @author @safe-global/safe-protocol
           * @dev IMPORTANT: The library is intended to be used with the Safe standard proxy that stores the singleton address
           *      at the storage slot 0. Use at your own risk with custom proxy implementations. The contract will allow invocations
           *      to the migration functions only via delegatecall.
           */
          contract SafeMigration is SafeStorage {
              /**
               * @notice Address of this contract
               */
              address public immutable MIGRATION_SINGLETON;
              /**
               * @notice Address of the Safe Singleton implementation
               */
              address public immutable SAFE_SINGLETON;
              /**
               * @notice Address of the Safe Singleton (L2) implementation
               */
              address public immutable SAFE_L2_SINGLETON;
              /**
               * @notice Address of the Fallback Handler
               */
              address public immutable SAFE_FALLBACK_HANDLER;
              /**
               * @notice Event indicating a change of a singleton address. Named master copy here for legacy reasons.
               * @param singleton New master copy address
               */
              event ChangedMasterCopy(address singleton);
              /**
               * @notice Modifier to make a function callable via delegatecall only.
               * If the function is called via a regular call, it will revert.
               */
              modifier onlyDelegateCall() {
                  require(address(this) != MIGRATION_SINGLETON, "Migration should only be called via delegatecall");
                  _;
              }
              /**
               * @notice Constructor
               * @param safeSingleton Address of the Safe Singleton implementation
               * @param safeL2Singleton Address of the SafeL2 Singleton implementation
               * @param fallbackHandler Address of the fallback handler implementation
               */
              constructor(address safeSingleton, address safeL2Singleton, address fallbackHandler) {
                  MIGRATION_SINGLETON = address(this);
                  require(hasCode(safeSingleton), "Safe Singleton is not deployed");
                  require(hasCode(safeL2Singleton), "Safe Singleton (L2) is not deployed");
                  require(hasCode(fallbackHandler), "fallback handler is not deployed");
                  SAFE_SINGLETON = safeSingleton;
                  SAFE_L2_SINGLETON = safeL2Singleton;
                  SAFE_FALLBACK_HANDLER = fallbackHandler;
              }
              /**
               * @notice Migrate the Safe contract to a new Safe Singleton implementation.
               */
              function migrateSingleton() public onlyDelegateCall {
                  singleton = SAFE_SINGLETON;
                  emit ChangedMasterCopy(SAFE_SINGLETON);
              }
              /**
               * @notice Migrate to Safe Singleton and set the fallback handler. This function is intended to be used when migrating
               *         a Safe to a version which also requires updating fallback handler.
               */
              function migrateWithFallbackHandler() external onlyDelegateCall {
                  migrateSingleton();
                  ISafe(address(this)).setFallbackHandler(SAFE_FALLBACK_HANDLER);
              }
              /**
               * @notice Migrate the Safe contract to a new Safe Singleton (L2) implementation.
               */
              function migrateL2Singleton() public onlyDelegateCall {
                  singleton = SAFE_L2_SINGLETON;
                  emit ChangedMasterCopy(SAFE_L2_SINGLETON);
              }
              /**
               * @notice Migrate to Safe Singleton (L2) and set the fallback handler. This function is intended to be used when migrating
               *         a Safe to a version which also requires updating fallback handler.
               */
              function migrateL2WithFallbackHandler() external onlyDelegateCall {
                  migrateL2Singleton();
                  ISafe(address(this)).setFallbackHandler(SAFE_FALLBACK_HANDLER);
              }
              /**
               * @notice Checks whether an account has code.
               * @param account The address of the account to be checked.
               * @return A boolean value indicating whether the address has code (true) or not (false).
               * @dev This function relies on the `extcodesize` assembly opcode to determine whether an address has code.
               * It does not reliably determine whether or not an address is a smart contract or an EOA.
               */
              function hasCode(address account) internal view returns (bool) {
                  uint256 size;
                  /* solhint-disable no-inline-assembly */
                  /// @solidity memory-safe-assembly
                  assembly {
                      size := extcodesize(account)
                  }
                  /* solhint-enable no-inline-assembly */
                  return size > 0;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title SafeStorage - Storage layout of the Safe contracts to be used in libraries.
           * @dev Should be always the first base contract of a library that is used with a Safe.
           * @author Richard Meissner - @rmeissner
           */
          contract SafeStorage {
              // From /common/Singleton.sol
              address internal singleton;
              // From /common/ModuleManager.sol
              mapping(address => address) internal modules;
              // From /common/OwnerManager.sol
              mapping(address => address) internal owners;
              uint256 internal ownerCount;
              uint256 internal threshold;
              // From /Safe.sol
              uint256 internal nonce;
              bytes32 internal _deprecatedDomainSeparator;
              mapping(bytes32 => uint256) internal signedMessages;
              mapping(address => mapping(bytes32 => uint256)) internal approvedHashes;
          }
          

          File 4 of 4: Safe
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "./base/ModuleManager.sol";
          import "./base/OwnerManager.sol";
          import "./base/FallbackManager.sol";
          import "./base/GuardManager.sol";
          import "./common/NativeCurrencyPaymentFallback.sol";
          import "./common/Singleton.sol";
          import "./common/SignatureDecoder.sol";
          import "./common/SecuredTokenTransfer.sol";
          import "./common/StorageAccessible.sol";
          import "./interfaces/ISignatureValidator.sol";
          import "./external/SafeMath.sol";
          /**
           * @title Safe - A multisignature wallet with support for confirmations using signed messages based on EIP-712.
           * @dev Most important concepts:
           *      - Threshold: Number of required confirmations for a Safe transaction.
           *      - Owners: List of addresses that control the Safe. They are the only ones that can add/remove owners, change the threshold and
           *        approve transactions. Managed in `OwnerManager`.
           *      - Transaction Hash: Hash of a transaction is calculated using the EIP-712 typed structured data hashing scheme.
           *      - Nonce: Each transaction should have a different nonce to prevent replay attacks.
           *      - Signature: A valid signature of an owner of the Safe for a transaction hash.
           *      - Guard: Guard is a contract that can execute pre- and post- transaction checks. Managed in `GuardManager`.
           *      - Modules: Modules are contracts that can be used to extend the write functionality of a Safe. Managed in `ModuleManager`.
           *      - Fallback: Fallback handler is a contract that can provide additional read-only functional for Safe. Managed in `FallbackManager`.
           *      Note: This version of the implementation contract doesn't emit events for the sake of gas efficiency and therefore requires a tracing node for indexing/
           *      For the events-based implementation see `SafeL2.sol`.
           * @author Stefan George - @Georgi87
           * @author Richard Meissner - @rmeissner
           */
          contract Safe is
              Singleton,
              NativeCurrencyPaymentFallback,
              ModuleManager,
              OwnerManager,
              SignatureDecoder,
              SecuredTokenTransfer,
              ISignatureValidatorConstants,
              FallbackManager,
              StorageAccessible,
              GuardManager
          {
              using SafeMath for uint256;
              string public constant VERSION = "1.4.1";
              // keccak256(
              //     "EIP712Domain(uint256 chainId,address verifyingContract)"
              // );
              bytes32 private constant DOMAIN_SEPARATOR_TYPEHASH = 0x47e79534a245952e8b16893a336b85a3d9ea9fa8c573f3d803afb92a79469218;
              // keccak256(
              //     "SafeTx(address to,uint256 value,bytes data,uint8 operation,uint256 safeTxGas,uint256 baseGas,uint256 gasPrice,address gasToken,address refundReceiver,uint256 nonce)"
              // );
              bytes32 private constant SAFE_TX_TYPEHASH = 0xbb8310d486368db6bd6f849402fdd73ad53d316b5a4b2644ad6efe0f941286d8;
              event SafeSetup(address indexed initiator, address[] owners, uint256 threshold, address initializer, address fallbackHandler);
              event ApproveHash(bytes32 indexed approvedHash, address indexed owner);
              event SignMsg(bytes32 indexed msgHash);
              event ExecutionFailure(bytes32 indexed txHash, uint256 payment);
              event ExecutionSuccess(bytes32 indexed txHash, uint256 payment);
              uint256 public nonce;
              bytes32 private _deprecatedDomainSeparator;
              // Mapping to keep track of all message hashes that have been approved by ALL REQUIRED owners
              mapping(bytes32 => uint256) public signedMessages;
              // Mapping to keep track of all hashes (message or transaction) that have been approved by ANY owners
              mapping(address => mapping(bytes32 => uint256)) public approvedHashes;
              // This constructor ensures that this contract can only be used as a singleton for Proxy contracts
              constructor() {
                  /**
                   * By setting the threshold it is not possible to call setup anymore,
                   * so we create a Safe with 0 owners and threshold 1.
                   * This is an unusable Safe, perfect for the singleton
                   */
                  threshold = 1;
              }
              /**
               * @notice Sets an initial storage of the Safe contract.
               * @dev This method can only be called once.
               *      If a proxy was created without setting up, anyone can call setup and claim the proxy.
               * @param _owners List of Safe owners.
               * @param _threshold Number of required confirmations for a Safe transaction.
               * @param to Contract address for optional delegate call.
               * @param data Data payload for optional delegate call.
               * @param fallbackHandler Handler for fallback calls to this contract
               * @param paymentToken Token that should be used for the payment (0 is ETH)
               * @param payment Value that should be paid
               * @param paymentReceiver Address that should receive the payment (or 0 if tx.origin)
               */
              function setup(
                  address[] calldata _owners,
                  uint256 _threshold,
                  address to,
                  bytes calldata data,
                  address fallbackHandler,
                  address paymentToken,
                  uint256 payment,
                  address payable paymentReceiver
              ) external {
                  // setupOwners checks if the Threshold is already set, therefore preventing that this method is called twice
                  setupOwners(_owners, _threshold);
                  if (fallbackHandler != address(0)) internalSetFallbackHandler(fallbackHandler);
                  // As setupOwners can only be called if the contract has not been initialized we don't need a check for setupModules
                  setupModules(to, data);
                  if (payment > 0) {
                      // To avoid running into issues with EIP-170 we reuse the handlePayment function (to avoid adjusting code of that has been verified we do not adjust the method itself)
                      // baseGas = 0, gasPrice = 1 and gas = payment => amount = (payment + 0) * 1 = payment
                      handlePayment(payment, 0, 1, paymentToken, paymentReceiver);
                  }
                  emit SafeSetup(msg.sender, _owners, _threshold, to, fallbackHandler);
              }
              /** @notice Executes a `operation` {0: Call, 1: DelegateCall}} transaction to `to` with `value` (Native Currency)
               *          and pays `gasPrice` * `gasLimit` in `gasToken` token to `refundReceiver`.
               * @dev The fees are always transferred, even if the user transaction fails.
               *      This method doesn't perform any sanity check of the transaction, such as:
               *      - if the contract at `to` address has code or not
               *      - if the `gasToken` is a contract or not
               *      It is the responsibility of the caller to perform such checks.
               * @param to Destination address of Safe transaction.
               * @param value Ether value of Safe transaction.
               * @param data Data payload of Safe transaction.
               * @param operation Operation type of Safe transaction.
               * @param safeTxGas Gas that should be used for the Safe transaction.
               * @param baseGas Gas costs that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
               * @param gasPrice Gas price that should be used for the payment calculation.
               * @param gasToken Token address (or 0 if ETH) that is used for the payment.
               * @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
               * @param signatures Signature data that should be verified.
               *                   Can be packed ECDSA signature ({bytes32 r}{bytes32 s}{uint8 v}), contract signature (EIP-1271) or approved hash.
               * @return success Boolean indicating transaction's success.
               */
              function execTransaction(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address payable refundReceiver,
                  bytes memory signatures
              ) public payable virtual returns (bool success) {
                  bytes32 txHash;
                  // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                  {
                      bytes memory txHashData = encodeTransactionData(
                          // Transaction info
                          to,
                          value,
                          data,
                          operation,
                          safeTxGas,
                          // Payment info
                          baseGas,
                          gasPrice,
                          gasToken,
                          refundReceiver,
                          // Signature info
                          nonce
                      );
                      // Increase nonce and execute transaction.
                      nonce++;
                      txHash = keccak256(txHashData);
                      checkSignatures(txHash, txHashData, signatures);
                  }
                  address guard = getGuard();
                  {
                      if (guard != address(0)) {
                          Guard(guard).checkTransaction(
                              // Transaction info
                              to,
                              value,
                              data,
                              operation,
                              safeTxGas,
                              // Payment info
                              baseGas,
                              gasPrice,
                              gasToken,
                              refundReceiver,
                              // Signature info
                              signatures,
                              msg.sender
                          );
                      }
                  }
                  // We require some gas to emit the events (at least 2500) after the execution and some to perform code until the execution (500)
                  // We also include the 1/64 in the check that is not send along with a call to counteract potential shortings because of EIP-150
                  require(gasleft() >= ((safeTxGas * 64) / 63).max(safeTxGas + 2500) + 500, "GS010");
                  // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                  {
                      uint256 gasUsed = gasleft();
                      // If the gasPrice is 0 we assume that nearly all available gas can be used (it is always more than safeTxGas)
                      // We only substract 2500 (compared to the 3000 before) to ensure that the amount passed is still higher than safeTxGas
                      success = execute(to, value, data, operation, gasPrice == 0 ? (gasleft() - 2500) : safeTxGas);
                      gasUsed = gasUsed.sub(gasleft());
                      // If no safeTxGas and no gasPrice was set (e.g. both are 0), then the internal tx is required to be successful
                      // This makes it possible to use `estimateGas` without issues, as it searches for the minimum gas where the tx doesn't revert
                      require(success || safeTxGas != 0 || gasPrice != 0, "GS013");
                      // We transfer the calculated tx costs to the tx.origin to avoid sending it to intermediate contracts that have made calls
                      uint256 payment = 0;
                      if (gasPrice > 0) {
                          payment = handlePayment(gasUsed, baseGas, gasPrice, gasToken, refundReceiver);
                      }
                      if (success) emit ExecutionSuccess(txHash, payment);
                      else emit ExecutionFailure(txHash, payment);
                  }
                  {
                      if (guard != address(0)) {
                          Guard(guard).checkAfterExecution(txHash, success);
                      }
                  }
              }
              /**
               * @notice Handles the payment for a Safe transaction.
               * @param gasUsed Gas used by the Safe transaction.
               * @param baseGas Gas costs that are independent of the transaction execution (e.g. base transaction fee, signature check, payment of the refund).
               * @param gasPrice Gas price that should be used for the payment calculation.
               * @param gasToken Token address (or 0 if ETH) that is used for the payment.
               * @return payment The amount of payment made in the specified token.
               */
              function handlePayment(
                  uint256 gasUsed,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address payable refundReceiver
              ) private returns (uint256 payment) {
                  // solhint-disable-next-line avoid-tx-origin
                  address payable receiver = refundReceiver == address(0) ? payable(tx.origin) : refundReceiver;
                  if (gasToken == address(0)) {
                      // For ETH we will only adjust the gas price to not be higher than the actual used gas price
                      payment = gasUsed.add(baseGas).mul(gasPrice < tx.gasprice ? gasPrice : tx.gasprice);
                      require(receiver.send(payment), "GS011");
                  } else {
                      payment = gasUsed.add(baseGas).mul(gasPrice);
                      require(transferToken(gasToken, receiver, payment), "GS012");
                  }
              }
              /**
               * @notice Checks whether the signature provided is valid for the provided data and hash. Reverts otherwise.
               * @param dataHash Hash of the data (could be either a message hash or transaction hash)
               * @param data That should be signed (this is passed to an external validator contract)
               * @param signatures Signature data that should be verified.
               *                   Can be packed ECDSA signature ({bytes32 r}{bytes32 s}{uint8 v}), contract signature (EIP-1271) or approved hash.
               */
              function checkSignatures(bytes32 dataHash, bytes memory data, bytes memory signatures) public view {
                  // Load threshold to avoid multiple storage loads
                  uint256 _threshold = threshold;
                  // Check that a threshold is set
                  require(_threshold > 0, "GS001");
                  checkNSignatures(dataHash, data, signatures, _threshold);
              }
              /**
               * @notice Checks whether the signature provided is valid for the provided data and hash. Reverts otherwise.
               * @dev Since the EIP-1271 does an external call, be mindful of reentrancy attacks.
               * @param dataHash Hash of the data (could be either a message hash or transaction hash)
               * @param data That should be signed (this is passed to an external validator contract)
               * @param signatures Signature data that should be verified.
               *                   Can be packed ECDSA signature ({bytes32 r}{bytes32 s}{uint8 v}), contract signature (EIP-1271) or approved hash.
               * @param requiredSignatures Amount of required valid signatures.
               */
              function checkNSignatures(bytes32 dataHash, bytes memory data, bytes memory signatures, uint256 requiredSignatures) public view {
                  // Check that the provided signature data is not too short
                  require(signatures.length >= requiredSignatures.mul(65), "GS020");
                  // There cannot be an owner with address 0.
                  address lastOwner = address(0);
                  address currentOwner;
                  uint8 v;
                  bytes32 r;
                  bytes32 s;
                  uint256 i;
                  for (i = 0; i < requiredSignatures; i++) {
                      (v, r, s) = signatureSplit(signatures, i);
                      if (v == 0) {
                          require(keccak256(data) == dataHash, "GS027");
                          // If v is 0 then it is a contract signature
                          // When handling contract signatures the address of the contract is encoded into r
                          currentOwner = address(uint160(uint256(r)));
                          // Check that signature data pointer (s) is not pointing inside the static part of the signatures bytes
                          // This check is not completely accurate, since it is possible that more signatures than the threshold are send.
                          // Here we only check that the pointer is not pointing inside the part that is being processed
                          require(uint256(s) >= requiredSignatures.mul(65), "GS021");
                          // Check that signature data pointer (s) is in bounds (points to the length of data -> 32 bytes)
                          require(uint256(s).add(32) <= signatures.length, "GS022");
                          // Check if the contract signature is in bounds: start of data is s + 32 and end is start + signature length
                          uint256 contractSignatureLen;
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              contractSignatureLen := mload(add(add(signatures, s), 0x20))
                          }
                          require(uint256(s).add(32).add(contractSignatureLen) <= signatures.length, "GS023");
                          // Check signature
                          bytes memory contractSignature;
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              // The signature data for contract signatures is appended to the concatenated signatures and the offset is stored in s
                              contractSignature := add(add(signatures, s), 0x20)
                          }
                          require(ISignatureValidator(currentOwner).isValidSignature(data, contractSignature) == EIP1271_MAGIC_VALUE, "GS024");
                      } else if (v == 1) {
                          // If v is 1 then it is an approved hash
                          // When handling approved hashes the address of the approver is encoded into r
                          currentOwner = address(uint160(uint256(r)));
                          // Hashes are automatically approved by the sender of the message or when they have been pre-approved via a separate transaction
                          require(msg.sender == currentOwner || approvedHashes[currentOwner][dataHash] != 0, "GS025");
                      } else if (v > 30) {
                          // If v > 30 then default va (27,28) has been adjusted for eth_sign flow
                          // To support eth_sign and similar we adjust v and hash the messageHash with the Ethereum message prefix before applying ecrecover
                          currentOwner = ecrecover(keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
          32", dataHash)), v - 4, r, s);
                      } else {
                          // Default is the ecrecover flow with the provided data hash
                          // Use ecrecover with the messageHash for EOA signatures
                          currentOwner = ecrecover(dataHash, v, r, s);
                      }
                      require(currentOwner > lastOwner && owners[currentOwner] != address(0) && currentOwner != SENTINEL_OWNERS, "GS026");
                      lastOwner = currentOwner;
                  }
              }
              /**
               * @notice Marks hash `hashToApprove` as approved.
               * @dev This can be used with a pre-approved hash transaction signature.
               *      IMPORTANT: The approved hash stays approved forever. There's no revocation mechanism, so it behaves similarly to ECDSA signatures
               * @param hashToApprove The hash to mark as approved for signatures that are verified by this contract.
               */
              function approveHash(bytes32 hashToApprove) external {
                  require(owners[msg.sender] != address(0), "GS030");
                  approvedHashes[msg.sender][hashToApprove] = 1;
                  emit ApproveHash(hashToApprove, msg.sender);
              }
              /**
               * @notice Returns the ID of the chain the contract is currently deployed on.
               * @return The ID of the current chain as a uint256.
               */
              function getChainId() public view returns (uint256) {
                  uint256 id;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      id := chainid()
                  }
                  return id;
              }
              /**
               * @dev Returns the domain separator for this contract, as defined in the EIP-712 standard.
               * @return bytes32 The domain separator hash.
               */
              function domainSeparator() public view returns (bytes32) {
                  return keccak256(abi.encode(DOMAIN_SEPARATOR_TYPEHASH, getChainId(), this));
              }
              /**
               * @notice Returns the pre-image of the transaction hash (see getTransactionHash).
               * @param to Destination address.
               * @param value Ether value.
               * @param data Data payload.
               * @param operation Operation type.
               * @param safeTxGas Gas that should be used for the safe transaction.
               * @param baseGas Gas costs for that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
               * @param gasPrice Maximum gas price that should be used for this transaction.
               * @param gasToken Token address (or 0 if ETH) that is used for the payment.
               * @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
               * @param _nonce Transaction nonce.
               * @return Transaction hash bytes.
               */
              function encodeTransactionData(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address refundReceiver,
                  uint256 _nonce
              ) public view returns (bytes memory) {
                  bytes32 safeTxHash = keccak256(
                      abi.encode(
                          SAFE_TX_TYPEHASH,
                          to,
                          value,
                          keccak256(data),
                          operation,
                          safeTxGas,
                          baseGas,
                          gasPrice,
                          gasToken,
                          refundReceiver,
                          _nonce
                      )
                  );
                  return abi.encodePacked(bytes1(0x19), bytes1(0x01), domainSeparator(), safeTxHash);
              }
              /**
               * @notice Returns transaction hash to be signed by owners.
               * @param to Destination address.
               * @param value Ether value.
               * @param data Data payload.
               * @param operation Operation type.
               * @param safeTxGas Fas that should be used for the safe transaction.
               * @param baseGas Gas costs for data used to trigger the safe transaction.
               * @param gasPrice Maximum gas price that should be used for this transaction.
               * @param gasToken Token address (or 0 if ETH) that is used for the payment.
               * @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
               * @param _nonce Transaction nonce.
               * @return Transaction hash.
               */
              function getTransactionHash(
                  address to,
                  uint256 value,
                  bytes calldata data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address refundReceiver,
                  uint256 _nonce
              ) public view returns (bytes32) {
                  return keccak256(encodeTransactionData(to, value, data, operation, safeTxGas, baseGas, gasPrice, gasToken, refundReceiver, _nonce));
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/Enum.sol";
          /**
           * @title Executor - A contract that can execute transactions
           * @author Richard Meissner - @rmeissner
           */
          abstract contract Executor {
              /**
               * @notice Executes either a delegatecall or a call with provided parameters.
               * @dev This method doesn't perform any sanity check of the transaction, such as:
               *      - if the contract at `to` address has code or not
               *      It is the responsibility of the caller to perform such checks.
               * @param to Destination address.
               * @param value Ether value.
               * @param data Data payload.
               * @param operation Operation type.
               * @return success boolean flag indicating if the call succeeded.
               */
              function execute(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation,
                  uint256 txGas
              ) internal returns (bool success) {
                  if (operation == Enum.Operation.DelegateCall) {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          success := delegatecall(txGas, to, add(data, 0x20), mload(data), 0, 0)
                      }
                  } else {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          success := call(txGas, to, value, add(data, 0x20), mload(data), 0, 0)
                      }
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/SelfAuthorized.sol";
          /**
           * @title Fallback Manager - A contract managing fallback calls made to this contract
           * @author Richard Meissner - @rmeissner
           */
          abstract contract FallbackManager is SelfAuthorized {
              event ChangedFallbackHandler(address indexed handler);
              // keccak256("fallback_manager.handler.address")
              bytes32 internal constant FALLBACK_HANDLER_STORAGE_SLOT = 0x6c9a6c4a39284e37ed1cf53d337577d14212a4870fb976a4366c693b939918d5;
              /**
               *  @notice Internal function to set the fallback handler.
               *  @param handler contract to handle fallback calls.
               */
              function internalSetFallbackHandler(address handler) internal {
                  /*
                      If a fallback handler is set to self, then the following attack vector is opened:
                      Imagine we have a function like this:
                      function withdraw() internal authorized {
                          withdrawalAddress.call.value(address(this).balance)("");
                      }
                      If the fallback method is triggered, the fallback handler appends the msg.sender address to the calldata and calls the fallback handler.
                      A potential attacker could call a Safe with the 3 bytes signature of a withdraw function. Since 3 bytes do not create a valid signature,
                      the call would end in a fallback handler. Since it appends the msg.sender address to the calldata, the attacker could craft an address 
                      where the first 3 bytes of the previous calldata + the first byte of the address make up a valid function signature. The subsequent call would result in unsanctioned access to Safe's internal protected methods.
                      For some reason, solidity matches the first 4 bytes of the calldata to a function signature, regardless if more data follow these 4 bytes.
                  */
                  require(handler != address(this), "GS400");
                  bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      sstore(slot, handler)
                  }
              }
              /**
               * @notice Set Fallback Handler to `handler` for the Safe.
               * @dev Only fallback calls without value and with data will be forwarded.
               *      This can only be done via a Safe transaction.
               *      Cannot be set to the Safe itself.
               * @param handler contract to handle fallback calls.
               */
              function setFallbackHandler(address handler) public authorized {
                  internalSetFallbackHandler(handler);
                  emit ChangedFallbackHandler(handler);
              }
              // @notice Forwards all calls to the fallback handler if set. Returns 0 if no handler is set.
              // @dev Appends the non-padded caller address to the calldata to be optionally used in the handler
              //      The handler can make us of `HandlerContext.sol` to extract the address.
              //      This is done because in the next call frame the `msg.sender` will be FallbackManager's address
              //      and having the original caller address may enable additional verification scenarios.
              // solhint-disable-next-line payable-fallback,no-complex-fallback
              fallback() external {
                  bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let handler := sload(slot)
                      if iszero(handler) {
                          return(0, 0)
                      }
                      calldatacopy(0, 0, calldatasize())
                      // The msg.sender address is shifted to the left by 12 bytes to remove the padding
                      // Then the address without padding is stored right after the calldata
                      mstore(calldatasize(), shl(96, caller()))
                      // Add 20 bytes for the address appended add the end
                      let success := call(gas(), handler, 0, 0, add(calldatasize(), 20), 0, 0)
                      returndatacopy(0, 0, returndatasize())
                      if iszero(success) {
                          revert(0, returndatasize())
                      }
                      return(0, returndatasize())
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/Enum.sol";
          import "../common/SelfAuthorized.sol";
          import "../interfaces/IERC165.sol";
          interface Guard is IERC165 {
              function checkTransaction(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation,
                  uint256 safeTxGas,
                  uint256 baseGas,
                  uint256 gasPrice,
                  address gasToken,
                  address payable refundReceiver,
                  bytes memory signatures,
                  address msgSender
              ) external;
              function checkAfterExecution(bytes32 txHash, bool success) external;
          }
          abstract contract BaseGuard is Guard {
              function supportsInterface(bytes4 interfaceId) external view virtual override returns (bool) {
                  return
                      interfaceId == type(Guard).interfaceId || // 0xe6d7a83a
                      interfaceId == type(IERC165).interfaceId; // 0x01ffc9a7
              }
          }
          /**
           * @title Guard Manager - A contract managing transaction guards which perform pre and post-checks on Safe transactions.
           * @author Richard Meissner - @rmeissner
           */
          abstract contract GuardManager is SelfAuthorized {
              event ChangedGuard(address indexed guard);
              // keccak256("guard_manager.guard.address")
              bytes32 internal constant GUARD_STORAGE_SLOT = 0x4a204f620c8c5ccdca3fd54d003badd85ba500436a431f0cbda4f558c93c34c8;
              /**
               * @dev Set a guard that checks transactions before execution
               *      This can only be done via a Safe transaction.
               *      ⚠️ IMPORTANT: Since a guard has full power to block Safe transaction execution,
               *        a broken guard can cause a denial of service for the Safe. Make sure to carefully
               *        audit the guard code and design recovery mechanisms.
               * @notice Set Transaction Guard `guard` for the Safe. Make sure you trust the guard.
               * @param guard The address of the guard to be used or the 0 address to disable the guard
               */
              function setGuard(address guard) external authorized {
                  if (guard != address(0)) {
                      require(Guard(guard).supportsInterface(type(Guard).interfaceId), "GS300");
                  }
                  bytes32 slot = GUARD_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      sstore(slot, guard)
                  }
                  emit ChangedGuard(guard);
              }
              /**
               * @dev Internal method to retrieve the current guard
               *      We do not have a public method because we're short on bytecode size limit,
               *      to retrieve the guard address, one can use `getStorageAt` from `StorageAccessible` contract
               *      with the slot `GUARD_STORAGE_SLOT`
               * @return guard The address of the guard
               */
              function getGuard() internal view returns (address guard) {
                  bytes32 slot = GUARD_STORAGE_SLOT;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      guard := sload(slot)
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/Enum.sol";
          import "../common/SelfAuthorized.sol";
          import "./Executor.sol";
          /**
           * @title Module Manager - A contract managing Safe modules
           * @notice Modules are extensions with unlimited access to a Safe that can be added to a Safe by its owners.
                     ⚠️ WARNING: Modules are a security risk since they can execute arbitrary transactions, 
                     so only trusted and audited modules should be added to a Safe. A malicious module can
                     completely takeover a Safe.
           * @author Stefan George - @Georgi87
           * @author Richard Meissner - @rmeissner
           */
          abstract contract ModuleManager is SelfAuthorized, Executor {
              event EnabledModule(address indexed module);
              event DisabledModule(address indexed module);
              event ExecutionFromModuleSuccess(address indexed module);
              event ExecutionFromModuleFailure(address indexed module);
              address internal constant SENTINEL_MODULES = address(0x1);
              mapping(address => address) internal modules;
              /**
               * @notice Setup function sets the initial storage of the contract.
               *         Optionally executes a delegate call to another contract to setup the modules.
               * @param to Optional destination address of call to execute.
               * @param data Optional data of call to execute.
               */
              function setupModules(address to, bytes memory data) internal {
                  require(modules[SENTINEL_MODULES] == address(0), "GS100");
                  modules[SENTINEL_MODULES] = SENTINEL_MODULES;
                  if (to != address(0)) {
                      require(isContract(to), "GS002");
                      // Setup has to complete successfully or transaction fails.
                      require(execute(to, 0, data, Enum.Operation.DelegateCall, type(uint256).max), "GS000");
                  }
              }
              /**
               * @notice Enables the module `module` for the Safe.
               * @dev This can only be done via a Safe transaction.
               * @param module Module to be whitelisted.
               */
              function enableModule(address module) public authorized {
                  // Module address cannot be null or sentinel.
                  require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                  // Module cannot be added twice.
                  require(modules[module] == address(0), "GS102");
                  modules[module] = modules[SENTINEL_MODULES];
                  modules[SENTINEL_MODULES] = module;
                  emit EnabledModule(module);
              }
              /**
               * @notice Disables the module `module` for the Safe.
               * @dev This can only be done via a Safe transaction.
               * @param prevModule Previous module in the modules linked list.
               * @param module Module to be removed.
               */
              function disableModule(address prevModule, address module) public authorized {
                  // Validate module address and check that it corresponds to module index.
                  require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                  require(modules[prevModule] == module, "GS103");
                  modules[prevModule] = modules[module];
                  modules[module] = address(0);
                  emit DisabledModule(module);
              }
              /**
               * @notice Execute `operation` (0: Call, 1: DelegateCall) to `to` with `value` (Native Token)
               * @dev Function is virtual to allow overriding for L2 singleton to emit an event for indexing.
               * @param to Destination address of module transaction.
               * @param value Ether value of module transaction.
               * @param data Data payload of module transaction.
               * @param operation Operation type of module transaction.
               * @return success Boolean flag indicating if the call succeeded.
               */
              function execTransactionFromModule(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation
              ) public virtual returns (bool success) {
                  // Only whitelisted modules are allowed.
                  require(msg.sender != SENTINEL_MODULES && modules[msg.sender] != address(0), "GS104");
                  // Execute transaction without further confirmations.
                  success = execute(to, value, data, operation, type(uint256).max);
                  if (success) emit ExecutionFromModuleSuccess(msg.sender);
                  else emit ExecutionFromModuleFailure(msg.sender);
              }
              /**
               * @notice Execute `operation` (0: Call, 1: DelegateCall) to `to` with `value` (Native Token) and return data
               * @param to Destination address of module transaction.
               * @param value Ether value of module transaction.
               * @param data Data payload of module transaction.
               * @param operation Operation type of module transaction.
               * @return success Boolean flag indicating if the call succeeded.
               * @return returnData Data returned by the call.
               */
              function execTransactionFromModuleReturnData(
                  address to,
                  uint256 value,
                  bytes memory data,
                  Enum.Operation operation
              ) public returns (bool success, bytes memory returnData) {
                  success = execTransactionFromModule(to, value, data, operation);
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // Load free memory location
                      let ptr := mload(0x40)
                      // We allocate memory for the return data by setting the free memory location to
                      // current free memory location + data size + 32 bytes for data size value
                      mstore(0x40, add(ptr, add(returndatasize(), 0x20)))
                      // Store the size
                      mstore(ptr, returndatasize())
                      // Store the data
                      returndatacopy(add(ptr, 0x20), 0, returndatasize())
                      // Point the return data to the correct memory location
                      returnData := ptr
                  }
              }
              /**
               * @notice Returns if an module is enabled
               * @return True if the module is enabled
               */
              function isModuleEnabled(address module) public view returns (bool) {
                  return SENTINEL_MODULES != module && modules[module] != address(0);
              }
              /**
               * @notice Returns an array of modules.
               *         If all entries fit into a single page, the next pointer will be 0x1.
               *         If another page is present, next will be the last element of the returned array.
               * @param start Start of the page. Has to be a module or start pointer (0x1 address)
               * @param pageSize Maximum number of modules that should be returned. Has to be > 0
               * @return array Array of modules.
               * @return next Start of the next page.
               */
              function getModulesPaginated(address start, uint256 pageSize) external view returns (address[] memory array, address next) {
                  require(start == SENTINEL_MODULES || isModuleEnabled(start), "GS105");
                  require(pageSize > 0, "GS106");
                  // Init array with max page size
                  array = new address[](pageSize);
                  // Populate return array
                  uint256 moduleCount = 0;
                  next = modules[start];
                  while (next != address(0) && next != SENTINEL_MODULES && moduleCount < pageSize) {
                      array[moduleCount] = next;
                      next = modules[next];
                      moduleCount++;
                  }
                  /**
                    Because of the argument validation, we can assume that the loop will always iterate over the valid module list values
                    and the `next` variable will either be an enabled module or a sentinel address (signalling the end). 
                    
                    If we haven't reached the end inside the loop, we need to set the next pointer to the last element of the modules array
                    because the `next` variable (which is a module by itself) acting as a pointer to the start of the next page is neither 
                    included to the current page, nor will it be included in the next one if you pass it as a start.
                  */
                  if (next != SENTINEL_MODULES) {
                      next = array[moduleCount - 1];
                  }
                  // Set correct size of returned array
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      mstore(array, moduleCount)
                  }
              }
              /**
               * @notice Returns true if `account` is a contract.
               * @dev This function will return false if invoked during the constructor of a contract,
               *      as the code is not actually created until after the constructor finishes.
               * @param account The address being queried
               */
              function isContract(address account) internal view returns (bool) {
                  uint256 size;
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      size := extcodesize(account)
                  }
                  return size > 0;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          import "../common/SelfAuthorized.sol";
          /**
           * @title OwnerManager - Manages Safe owners and a threshold to authorize transactions.
           * @dev Uses a linked list to store the owners because the code generate by the solidity compiler
           *      is more efficient than using a dynamic array.
           * @author Stefan George - @Georgi87
           * @author Richard Meissner - @rmeissner
           */
          abstract contract OwnerManager is SelfAuthorized {
              event AddedOwner(address indexed owner);
              event RemovedOwner(address indexed owner);
              event ChangedThreshold(uint256 threshold);
              address internal constant SENTINEL_OWNERS = address(0x1);
              mapping(address => address) internal owners;
              uint256 internal ownerCount;
              uint256 internal threshold;
              /**
               * @notice Sets the initial storage of the contract.
               * @param _owners List of Safe owners.
               * @param _threshold Number of required confirmations for a Safe transaction.
               */
              function setupOwners(address[] memory _owners, uint256 _threshold) internal {
                  // Threshold can only be 0 at initialization.
                  // Check ensures that setup function can only be called once.
                  require(threshold == 0, "GS200");
                  // Validate that threshold is smaller than number of added owners.
                  require(_threshold <= _owners.length, "GS201");
                  // There has to be at least one Safe owner.
                  require(_threshold >= 1, "GS202");
                  // Initializing Safe owners.
                  address currentOwner = SENTINEL_OWNERS;
                  for (uint256 i = 0; i < _owners.length; i++) {
                      // Owner address cannot be null.
                      address owner = _owners[i];
                      require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this) && currentOwner != owner, "GS203");
                      // No duplicate owners allowed.
                      require(owners[owner] == address(0), "GS204");
                      owners[currentOwner] = owner;
                      currentOwner = owner;
                  }
                  owners[currentOwner] = SENTINEL_OWNERS;
                  ownerCount = _owners.length;
                  threshold = _threshold;
              }
              /**
               * @notice Adds the owner `owner` to the Safe and updates the threshold to `_threshold`.
               * @dev This can only be done via a Safe transaction.
               * @param owner New owner address.
               * @param _threshold New threshold.
               */
              function addOwnerWithThreshold(address owner, uint256 _threshold) public authorized {
                  // Owner address cannot be null, the sentinel or the Safe itself.
                  require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this), "GS203");
                  // No duplicate owners allowed.
                  require(owners[owner] == address(0), "GS204");
                  owners[owner] = owners[SENTINEL_OWNERS];
                  owners[SENTINEL_OWNERS] = owner;
                  ownerCount++;
                  emit AddedOwner(owner);
                  // Change threshold if threshold was changed.
                  if (threshold != _threshold) changeThreshold(_threshold);
              }
              /**
               * @notice Removes the owner `owner` from the Safe and updates the threshold to `_threshold`.
               * @dev This can only be done via a Safe transaction.
               * @param prevOwner Owner that pointed to the owner to be removed in the linked list
               * @param owner Owner address to be removed.
               * @param _threshold New threshold.
               */
              function removeOwner(address prevOwner, address owner, uint256 _threshold) public authorized {
                  // Only allow to remove an owner, if threshold can still be reached.
                  require(ownerCount - 1 >= _threshold, "GS201");
                  // Validate owner address and check that it corresponds to owner index.
                  require(owner != address(0) && owner != SENTINEL_OWNERS, "GS203");
                  require(owners[prevOwner] == owner, "GS205");
                  owners[prevOwner] = owners[owner];
                  owners[owner] = address(0);
                  ownerCount--;
                  emit RemovedOwner(owner);
                  // Change threshold if threshold was changed.
                  if (threshold != _threshold) changeThreshold(_threshold);
              }
              /**
               * @notice Replaces the owner `oldOwner` in the Safe with `newOwner`.
               * @dev This can only be done via a Safe transaction.
               * @param prevOwner Owner that pointed to the owner to be replaced in the linked list
               * @param oldOwner Owner address to be replaced.
               * @param newOwner New owner address.
               */
              function swapOwner(address prevOwner, address oldOwner, address newOwner) public authorized {
                  // Owner address cannot be null, the sentinel or the Safe itself.
                  require(newOwner != address(0) && newOwner != SENTINEL_OWNERS && newOwner != address(this), "GS203");
                  // No duplicate owners allowed.
                  require(owners[newOwner] == address(0), "GS204");
                  // Validate oldOwner address and check that it corresponds to owner index.
                  require(oldOwner != address(0) && oldOwner != SENTINEL_OWNERS, "GS203");
                  require(owners[prevOwner] == oldOwner, "GS205");
                  owners[newOwner] = owners[oldOwner];
                  owners[prevOwner] = newOwner;
                  owners[oldOwner] = address(0);
                  emit RemovedOwner(oldOwner);
                  emit AddedOwner(newOwner);
              }
              /**
               * @notice Changes the threshold of the Safe to `_threshold`.
               * @dev This can only be done via a Safe transaction.
               * @param _threshold New threshold.
               */
              function changeThreshold(uint256 _threshold) public authorized {
                  // Validate that threshold is smaller than number of owners.
                  require(_threshold <= ownerCount, "GS201");
                  // There has to be at least one Safe owner.
                  require(_threshold >= 1, "GS202");
                  threshold = _threshold;
                  emit ChangedThreshold(threshold);
              }
              /**
               * @notice Returns the number of required confirmations for a Safe transaction aka the threshold.
               * @return Threshold number.
               */
              function getThreshold() public view returns (uint256) {
                  return threshold;
              }
              /**
               * @notice Returns if `owner` is an owner of the Safe.
               * @return Boolean if owner is an owner of the Safe.
               */
              function isOwner(address owner) public view returns (bool) {
                  return owner != SENTINEL_OWNERS && owners[owner] != address(0);
              }
              /**
               * @notice Returns a list of Safe owners.
               * @return Array of Safe owners.
               */
              function getOwners() public view returns (address[] memory) {
                  address[] memory array = new address[](ownerCount);
                  // populate return array
                  uint256 index = 0;
                  address currentOwner = owners[SENTINEL_OWNERS];
                  while (currentOwner != SENTINEL_OWNERS) {
                      array[index] = currentOwner;
                      currentOwner = owners[currentOwner];
                      index++;
                  }
                  return array;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title Enum - Collection of enums used in Safe contracts.
           * @author Richard Meissner - @rmeissner
           */
          abstract contract Enum {
              enum Operation {
                  Call,
                  DelegateCall
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title NativeCurrencyPaymentFallback - A contract that has a fallback to accept native currency payments.
           * @author Richard Meissner - @rmeissner
           */
          abstract contract NativeCurrencyPaymentFallback {
              event SafeReceived(address indexed sender, uint256 value);
              /**
               * @notice Receive function accepts native currency transactions.
               * @dev Emits an event with sender and received value.
               */
              receive() external payable {
                  emit SafeReceived(msg.sender, msg.value);
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title SecuredTokenTransfer - Secure token transfer.
           * @author Richard Meissner - @rmeissner
           */
          abstract contract SecuredTokenTransfer {
              /**
               * @notice Transfers a token and returns a boolean if it was a success
               * @dev It checks the return data of the transfer call and returns true if the transfer was successful.
               *      It doesn't check if the `token` address is a contract or not.
               * @param token Token that should be transferred
               * @param receiver Receiver to whom the token should be transferred
               * @param amount The amount of tokens that should be transferred
               * @return transferred Returns true if the transfer was successful
               */
              function transferToken(address token, address receiver, uint256 amount) internal returns (bool transferred) {
                  // 0xa9059cbb - keccack("transfer(address,uint256)")
                  bytes memory data = abi.encodeWithSelector(0xa9059cbb, receiver, amount);
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // We write the return value to scratch space.
                      // See https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory
                      let success := call(sub(gas(), 10000), token, 0, add(data, 0x20), mload(data), 0, 0x20)
                      switch returndatasize()
                      case 0 {
                          transferred := success
                      }
                      case 0x20 {
                          transferred := iszero(or(iszero(success), iszero(mload(0))))
                      }
                      default {
                          transferred := 0
                      }
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title SelfAuthorized - Authorizes current contract to perform actions to itself.
           * @author Richard Meissner - @rmeissner
           */
          abstract contract SelfAuthorized {
              function requireSelfCall() private view {
                  require(msg.sender == address(this), "GS031");
              }
              modifier authorized() {
                  // Modifiers are copied around during compilation. This is a function call as it minimized the bytecode size
                  requireSelfCall();
                  _;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title SignatureDecoder - Decodes signatures encoded as bytes
           * @author Richard Meissner - @rmeissner
           */
          abstract contract SignatureDecoder {
              /**
               * @notice Splits signature bytes into `uint8 v, bytes32 r, bytes32 s`.
               * @dev Make sure to perform a bounds check for @param pos, to avoid out of bounds access on @param signatures
               *      The signature format is a compact form of {bytes32 r}{bytes32 s}{uint8 v}
               *      Compact means uint8 is not padded to 32 bytes.
               * @param pos Which signature to read.
               *            A prior bounds check of this parameter should be performed, to avoid out of bounds access.
               * @param signatures Concatenated {r, s, v} signatures.
               * @return v Recovery ID or Safe signature type.
               * @return r Output value r of the signature.
               * @return s Output value s of the signature.
               */
              function signatureSplit(bytes memory signatures, uint256 pos) internal pure returns (uint8 v, bytes32 r, bytes32 s) {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let signaturePos := mul(0x41, pos)
                      r := mload(add(signatures, add(signaturePos, 0x20)))
                      s := mload(add(signatures, add(signaturePos, 0x40)))
                      /**
                       * Here we are loading the last 32 bytes, including 31 bytes
                       * of 's'. There is no 'mload8' to do this.
                       * 'byte' is not working due to the Solidity parser, so lets
                       * use the second best option, 'and'
                       */
                      v := and(mload(add(signatures, add(signaturePos, 0x41))), 0xff)
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title Singleton - Base for singleton contracts (should always be the first super contract)
           *        This contract is tightly coupled to our proxy contract (see `proxies/SafeProxy.sol`)
           * @author Richard Meissner - @rmeissner
           */
          abstract contract Singleton {
              // singleton always has to be the first declared variable to ensure the same location as in the Proxy contract.
              // It should also always be ensured the address is stored alone (uses a full word)
              address private singleton;
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title StorageAccessible - A generic base contract that allows callers to access all internal storage.
           * @notice See https://github.com/gnosis/util-contracts/blob/bb5fe5fb5df6d8400998094fb1b32a178a47c3a1/contracts/StorageAccessible.sol
           *         It removes a method from the original contract not needed for the Safe contracts.
           * @author Gnosis Developers
           */
          abstract contract StorageAccessible {
              /**
               * @notice Reads `length` bytes of storage in the currents contract
               * @param offset - the offset in the current contract's storage in words to start reading from
               * @param length - the number of words (32 bytes) of data to read
               * @return the bytes that were read.
               */
              function getStorageAt(uint256 offset, uint256 length) public view returns (bytes memory) {
                  bytes memory result = new bytes(length * 32);
                  for (uint256 index = 0; index < length; index++) {
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let word := sload(add(offset, index))
                          mstore(add(add(result, 0x20), mul(index, 0x20)), word)
                      }
                  }
                  return result;
              }
              /**
               * @dev Performs a delegatecall on a targetContract in the context of self.
               * Internally reverts execution to avoid side effects (making it static).
               *
               * This method reverts with data equal to `abi.encode(bool(success), bytes(response))`.
               * Specifically, the `returndata` after a call to this method will be:
               * `success:bool || response.length:uint256 || response:bytes`.
               *
               * @param targetContract Address of the contract containing the code to execute.
               * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
               */
              function simulateAndRevert(address targetContract, bytes memory calldataPayload) external {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      let success := delegatecall(gas(), targetContract, add(calldataPayload, 0x20), mload(calldataPayload), 0, 0)
                      mstore(0x00, success)
                      mstore(0x20, returndatasize())
                      returndatacopy(0x40, 0, returndatasize())
                      revert(0, add(returndatasize(), 0x40))
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /**
           * @title SafeMath
           * @notice Math operations with safety checks that revert on error (overflow/underflow)
           */
          library SafeMath {
              /**
               * @notice Multiplies two numbers, reverts on overflow.
               * @param a First number
               * @param b Second number
               * @return Product of a and b
               */
              function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                  // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                  // benefit is lost if 'b' is also tested.
                  // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
                  if (a == 0) {
                      return 0;
                  }
                  uint256 c = a * b;
                  require(c / a == b);
                  return c;
              }
              /**
               * @notice Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
               * @param a First number
               * @param b Second number
               * @return Difference of a and b
               */
              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                  require(b <= a);
                  uint256 c = a - b;
                  return c;
              }
              /**
               * @notice Adds two numbers, reverts on overflow.
               * @param a First number
               * @param b Second number
               * @return Sum of a and b
               */
              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                  uint256 c = a + b;
                  require(c >= a);
                  return c;
              }
              /**
               * @notice Returns the largest of two numbers.
               * @param a First number
               * @param b Second number
               * @return Largest of a and b
               */
              function max(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a >= b ? a : b;
              }
          }
          // SPDX-License-Identifier: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          /// @notice More details at https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/introspection/IERC165.sol
          interface IERC165 {
              /**
               * @dev Returns true if this contract implements the interface defined by `interfaceId`.
               * See the corresponding EIP section
               * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified
               * 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: LGPL-3.0-only
          pragma solidity >=0.7.0 <0.9.0;
          contract ISignatureValidatorConstants {
              // bytes4(keccak256("isValidSignature(bytes,bytes)")
              bytes4 internal constant EIP1271_MAGIC_VALUE = 0x20c13b0b;
          }
          abstract contract ISignatureValidator is ISignatureValidatorConstants {
              /**
               * @notice Legacy EIP1271 method to validate a signature.
               * @param _data Arbitrary length data signed on the behalf of address(this).
               * @param _signature Signature byte array associated with _data.
               *
               * MUST return the bytes4 magic value 0x20c13b0b when function passes.
               * MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5)
               * MUST allow external calls
               */
              function isValidSignature(bytes memory _data, bytes memory _signature) public view virtual returns (bytes4);
          }