ETH Price: $2,540.59 (-2.16%)

Transaction Decoder

Block:
20427704 at Jul-31-2024 04:23:47 PM +UTC
Transaction Fee:
0.001319608 ETH $3.35
Gas Used:
77,624 Gas / 17 Gwei

Emitted Events:

46 AppProxyUpgradeable.0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925( 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925, 0x000000000000000000000000e094a22330b1eb7d69bb6342a63c59c07c1a5b4c, 0x000000000000000000000000c92e8bdf79f0507f65a392b0ab4667716bfe0110, 0000000000000000000000000000000000000000000000000000000000000000 )
47 GnosisSafeProxy.0x442e715f626346e8c54381002da614f62bee8d27386535b2521ec8540898556e( 0x442e715f626346e8c54381002da614f62bee8d27386535b2521ec8540898556e, 324f9fa31426566f35078e3d85fbb031f14e68af80963c086876ea745c713308, 0000000000000000000000000000000000000000000000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
(Lido: Execution Layer Rewards Vault)
34.734326516540412816 Eth34.734459971535035184 Eth0.000133454994622368
0xae7ab965...312D7fE84
0xC2D02A5F...BbF368A01
0.009971212432360983 Eth
Nonce: 264
0.008651604432360983 Eth
Nonce: 265
0.001319608
0xE094a223...07c1A5B4c

Execution Trace

GnosisSafeProxy.6a761202( )
  • GnosisSafe.execTransaction( to=0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84, value=0, data=0x095EA7B3000000000000000000000000C92E8BDF79F0507F65A392B0AB4667716BFE01100000000000000000000000000000000000000000000000000000000000000000, operation=0, safeTxGas=0, baseGas=0, gasPrice=0, gasToken=0x0000000000000000000000000000000000000000, refundReceiver=0x0000000000000000000000000000000000000000, signatures=0x9533F966048BEE76EF19480B352948F418BA5350F7C806905F0E9267476B592503F085D0C582D93E9FAAC3B52DE55381D4926D6D6748452B5AEFF2B02D0812631B000000000000000000000000C2D02A5F752F92B183B3C3769C0905ABBF368A01000000000000000000000000000000000000000000000000000000000000000001 ) => ( success=True )
    • Null: 0x000...001.324f9fa3( )
    • AppProxyUpgradeable.095ea7b3( )
      • KernelProxy.be00bbd8( )
        • Kernel.getApp( _namespace=F1F3EB40F5BC1AD1344716CED8B8A0431D840B5783AEA1FD01786BC26F35AC0F, _appId=3CA7C3E38968823CCB4C78EA688DF41356F182AE1D159E4EE608D30D68CEF320 ) => ( 0x17144556fd3424EDC8Fc8A4C940B2D04936d17eb )
        • Lido.approve( _spender=0xC92E8bdf79f0507f65a392b0ab4667716BFE0110, _amount=0 ) => ( True )
          File 1 of 6: 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 - <[email protected]>
          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 - <[email protected]>
          /// @author Richard Meissner - <[email protected]>
          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 - <[email protected]>
          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 6: AppProxyUpgradeable
          // File: contracts/common/UnstructuredStorage.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          library UnstructuredStorage {
              function getStorageBool(bytes32 position) internal view returns (bool data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageAddress(bytes32 position) internal view returns (address data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
                  assembly { data := sload(position) }
              }
          
              function setStorageBool(bytes32 position, bool data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageAddress(bytes32 position, address data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageBytes32(bytes32 position, bytes32 data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageUint256(bytes32 position, uint256 data) internal {
                  assembly { sstore(position, data) }
              }
          }
          
          // File: contracts/acl/IACL.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IACL {
              function initialize(address permissionsCreator) external;
          
              // TODO: this should be external
              // See https://github.com/ethereum/solidity/issues/4832
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          }
          
          // File: contracts/common/IVaultRecoverable.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IVaultRecoverable {
              event RecoverToVault(address indexed vault, address indexed token, uint256 amount);
          
              function transferToVault(address token) external;
          
              function allowRecoverability(address token) external view returns (bool);
              function getRecoveryVault() external view returns (address);
          }
          
          // File: contracts/kernel/IKernel.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          interface IKernelEvents {
              event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
          }
          
          
          // This should be an interface, but interfaces can't inherit yet :(
          contract IKernel is IKernelEvents, IVaultRecoverable {
              function acl() public view returns (IACL);
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          
              function setApp(bytes32 namespace, bytes32 appId, address app) public;
              function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
          }
          
          // File: contracts/apps/AppStorage.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          contract AppStorage {
              using UnstructuredStorage for bytes32;
          
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
              bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
              */
              bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
              bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;
          
              function kernel() public view returns (IKernel) {
                  return IKernel(KERNEL_POSITION.getStorageAddress());
              }
          
              function appId() public view returns (bytes32) {
                  return APP_ID_POSITION.getStorageBytes32();
              }
          
              function setKernel(IKernel _kernel) internal {
                  KERNEL_POSITION.setStorageAddress(address(_kernel));
              }
          
              function setAppId(bytes32 _appId) internal {
                  APP_ID_POSITION.setStorageBytes32(_appId);
              }
          }
          
          // File: contracts/common/IsContract.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract IsContract {
              /*
              * NOTE: this should NEVER be used for authentication
              * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
              *
              * This is only intended to be used as a sanity check that an address is actually a contract,
              * RATHER THAN an address not being a contract.
              */
              function isContract(address _target) internal view returns (bool) {
                  if (_target == address(0)) {
                      return false;
                  }
          
                  uint256 size;
                  assembly { size := extcodesize(_target) }
                  return size > 0;
              }
          }
          
          // File: contracts/lib/misc/ERCProxy.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract ERCProxy {
              uint256 internal constant FORWARDING = 1;
              uint256 internal constant UPGRADEABLE = 2;
          
              function proxyType() public pure returns (uint256 proxyTypeId);
              function implementation() public view returns (address codeAddr);
          }
          
          // File: contracts/common/DelegateProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract DelegateProxy is ERCProxy, IsContract {
              uint256 internal constant FWD_GAS_LIMIT = 10000;
          
              /**
              * @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
              * @param _dst Destination address to perform the delegatecall
              * @param _calldata Calldata for the delegatecall
              */
              function delegatedFwd(address _dst, bytes _calldata) internal {
                  require(isContract(_dst));
                  uint256 fwdGasLimit = FWD_GAS_LIMIT;
          
                  assembly {
                      let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
                      let size := returndatasize
                      let ptr := mload(0x40)
                      returndatacopy(ptr, 0, size)
          
                      // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
                      // if the call returned error data, forward it
                      switch result case 0 { revert(ptr, size) }
                      default { return(ptr, size) }
                  }
              }
          }
          
          // File: contracts/common/DepositableStorage.sol
          
          pragma solidity 0.4.24;
          
          
          
          contract DepositableStorage {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.depositableStorage.depositable")
              bytes32 internal constant DEPOSITABLE_POSITION = 0x665fd576fbbe6f247aff98f5c94a561e3f71ec2d3c988d56f12d342396c50cea;
          
              function isDepositable() public view returns (bool) {
                  return DEPOSITABLE_POSITION.getStorageBool();
              }
          
              function setDepositable(bool _depositable) internal {
                  DEPOSITABLE_POSITION.setStorageBool(_depositable);
              }
          }
          
          // File: contracts/common/DepositableDelegateProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract DepositableDelegateProxy is DepositableStorage, DelegateProxy {
              event ProxyDeposit(address sender, uint256 value);
          
              function () external payable {
                  uint256 forwardGasThreshold = FWD_GAS_LIMIT;
                  bytes32 isDepositablePosition = DEPOSITABLE_POSITION;
          
                  // Optimized assembly implementation to prevent EIP-1884 from breaking deposits, reference code in Solidity:
                  // https://github.com/aragon/aragonOS/blob/v4.2.1/contracts/common/DepositableDelegateProxy.sol#L10-L20
                  assembly {
                      // Continue only if the gas left is lower than the threshold for forwarding to the implementation code,
                      // otherwise continue outside of the assembly block.
                      if lt(gas, forwardGasThreshold) {
                          // Only accept the deposit and emit an event if all of the following are true:
                          // the proxy accepts deposits (isDepositable), msg.data.length == 0, and msg.value > 0
                          if and(and(sload(isDepositablePosition), iszero(calldatasize)), gt(callvalue, 0)) {
                              // Equivalent Solidity code for emitting the event:
                              // emit ProxyDeposit(msg.sender, msg.value);
          
                              let logData := mload(0x40) // free memory pointer
                              mstore(logData, caller) // add 'msg.sender' to the log data (first event param)
                              mstore(add(logData, 0x20), callvalue) // add 'msg.value' to the log data (second event param)
          
                              // Emit an event with one topic to identify the event: keccak256('ProxyDeposit(address,uint256)') = 0x15ee...dee1
                              log1(logData, 0x40, 0x15eeaa57c7bd188c1388020bcadc2c436ec60d647d36ef5b9eb3c742217ddee1)
          
                              stop() // Stop. Exits execution context
                          }
          
                          // If any of above checks failed, revert the execution (if ETH was sent, it is returned to the sender)
                          revert(0, 0)
                      }
                  }
          
                  address target = implementation();
                  delegatedFwd(target, msg.data);
              }
          }
          
          // File: contracts/kernel/KernelConstants.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract KernelAppIds {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
              */
              bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
          }
          
          
          contract KernelNamespaceConstants {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
              */
              bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
          }
          
          // File: contracts/apps/AppProxyBase.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          contract AppProxyBase is AppStorage, DepositableDelegateProxy, KernelNamespaceConstants {
              /**
              * @dev Initialize AppProxy
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public {
                  setKernel(_kernel);
                  setAppId(_appId);
          
                  // Implicit check that kernel is actually a Kernel
                  // The EVM doesn't actually provide a way for us to make sure, but we can force a revert to
                  // occur if the kernel is set to 0x0 or a non-code address when we try to call a method on
                  // it.
                  address appCode = getAppBase(_appId);
          
                  // If initialize payload is provided, it will be executed
                  if (_initializePayload.length > 0) {
                      require(isContract(appCode));
                      // Cannot make delegatecall as a delegateproxy.delegatedFwd as it
                      // returns ending execution context and halts contract deployment
                      require(appCode.delegatecall(_initializePayload));
                  }
              }
          
              function getAppBase(bytes32 _appId) internal view returns (address) {
                  return kernel().getApp(KERNEL_APP_BASES_NAMESPACE, _appId);
              }
          }
          
          // File: contracts/apps/AppProxyUpgradeable.sol
          
          pragma solidity 0.4.24;
          
          
          
          contract AppProxyUpgradeable is AppProxyBase {
              /**
              * @dev Initialize AppProxyUpgradeable (makes it an upgradeable Aragon app)
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
                  AppProxyBase(_kernel, _appId, _initializePayload)
                  public // solium-disable-line visibility-first
              {
                  // solium-disable-previous-line no-empty-blocks
              }
          
              /**
               * @dev ERC897, the address the proxy would delegate calls to
               */
              function implementation() public view returns (address) {
                  return getAppBase(appId());
              }
          
              /**
               * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
               */
              function proxyType() public pure returns (uint256 proxyTypeId) {
                  return UPGRADEABLE;
              }
          }

          File 3 of 6: 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 - <[email protected]>
          /// @author Richard Meissner - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          /// @author Richard Meissner - <[email protected]>
          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 - <[email protected]>
          /// @author Richard Meissner - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 - <[email protected]>
          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 4 of 6: KernelProxy
          /**
           *Submitted for verification at Etherscan.io on 2020-02-06
          */
          
          // File: contracts/acl/IACL.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IACL {
              function initialize(address permissionsCreator) external;
          
              // TODO: this should be external
              // See https://github.com/ethereum/solidity/issues/4832
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          }
          
          // File: contracts/common/IVaultRecoverable.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IVaultRecoverable {
              event RecoverToVault(address indexed vault, address indexed token, uint256 amount);
          
              function transferToVault(address token) external;
          
              function allowRecoverability(address token) external view returns (bool);
              function getRecoveryVault() external view returns (address);
          }
          
          // File: contracts/kernel/IKernel.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          interface IKernelEvents {
              event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
          }
          
          
          // This should be an interface, but interfaces can't inherit yet :(
          contract IKernel is IKernelEvents, IVaultRecoverable {
              function acl() public view returns (IACL);
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          
              function setApp(bytes32 namespace, bytes32 appId, address app) public;
              function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
          }
          
          // File: contracts/kernel/KernelConstants.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract KernelAppIds {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
              */
              bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
          }
          
          
          contract KernelNamespaceConstants {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
              */
              bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
          }
          
          // File: contracts/kernel/KernelStorage.sol
          
          pragma solidity 0.4.24;
          
          
          contract KernelStorage {
              // namespace => app id => address
              mapping (bytes32 => mapping (bytes32 => address)) public apps;
              bytes32 public recoveryVaultAppId;
          }
          
          // File: contracts/acl/ACLSyntaxSugar.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract ACLSyntaxSugar {
              function arr() internal pure returns (uint256[]) {
                  return new uint256[](0);
              }
          
              function arr(bytes32 _a) internal pure returns (uint256[] r) {
                  return arr(uint256(_a));
              }
          
              function arr(bytes32 _a, bytes32 _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
          
              function arr(address _a) internal pure returns (uint256[] r) {
                  return arr(uint256(_a));
              }
          
              function arr(address _a, address _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
          
              function arr(address _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), _b, _c);
              }
          
              function arr(address _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), _b, _c, _d);
              }
          
              function arr(address _a, uint256 _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
          
              function arr(address _a, address _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), _c, _d, _e);
              }
          
              function arr(address _a, address _b, address _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), uint256(_c));
              }
          
              function arr(address _a, address _b, uint256 _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), uint256(_c));
              }
          
              function arr(uint256 _a) internal pure returns (uint256[] r) {
                  r = new uint256[](1);
                  r[0] = _a;
              }
          
              function arr(uint256 _a, uint256 _b) internal pure returns (uint256[] r) {
                  r = new uint256[](2);
                  r[0] = _a;
                  r[1] = _b;
              }
          
              function arr(uint256 _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
                  r = new uint256[](3);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
              }
          
              function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
                  r = new uint256[](4);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
                  r[3] = _d;
              }
          
              function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
                  r = new uint256[](5);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
                  r[3] = _d;
                  r[4] = _e;
              }
          }
          
          
          contract ACLHelpers {
              function decodeParamOp(uint256 _x) internal pure returns (uint8 b) {
                  return uint8(_x >> (8 * 30));
              }
          
              function decodeParamId(uint256 _x) internal pure returns (uint8 b) {
                  return uint8(_x >> (8 * 31));
              }
          
              function decodeParamsList(uint256 _x) internal pure returns (uint32 a, uint32 b, uint32 c) {
                  a = uint32(_x);
                  b = uint32(_x >> (8 * 4));
                  c = uint32(_x >> (8 * 8));
              }
          }
          
          // File: contracts/common/ConversionHelpers.sol
          
          pragma solidity ^0.4.24;
          
          
          library ConversionHelpers {
              string private constant ERROR_IMPROPER_LENGTH = "CONVERSION_IMPROPER_LENGTH";
          
              function dangerouslyCastUintArrayToBytes(uint256[] memory _input) internal pure returns (bytes memory output) {
                  // Force cast the uint256[] into a bytes array, by overwriting its length
                  // Note that the bytes array doesn't need to be initialized as we immediately overwrite it
                  // with the input and a new length. The input becomes invalid from this point forward.
                  uint256 byteLength = _input.length * 32;
                  assembly {
                      output := _input
                      mstore(output, byteLength)
                  }
              }
          
              function dangerouslyCastBytesToUintArray(bytes memory _input) internal pure returns (uint256[] memory output) {
                  // Force cast the bytes array into a uint256[], by overwriting its length
                  // Note that the uint256[] doesn't need to be initialized as we immediately overwrite it
                  // with the input and a new length. The input becomes invalid from this point forward.
                  uint256 intsLength = _input.length / 32;
                  require(_input.length == intsLength * 32, ERROR_IMPROPER_LENGTH);
          
                  assembly {
                      output := _input
                      mstore(output, intsLength)
                  }
              }
          }
          
          // File: contracts/common/IsContract.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract IsContract {
              /*
              * NOTE: this should NEVER be used for authentication
              * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
              *
              * This is only intended to be used as a sanity check that an address is actually a contract,
              * RATHER THAN an address not being a contract.
              */
              function isContract(address _target) internal view returns (bool) {
                  if (_target == address(0)) {
                      return false;
                  }
          
                  uint256 size;
                  assembly { size := extcodesize(_target) }
                  return size > 0;
              }
          }
          
          // File: contracts/common/Uint256Helpers.sol
          
          pragma solidity ^0.4.24;
          
          
          library Uint256Helpers {
              uint256 private constant MAX_UINT64 = uint64(-1);
          
              string private constant ERROR_NUMBER_TOO_BIG = "UINT64_NUMBER_TOO_BIG";
          
              function toUint64(uint256 a) internal pure returns (uint64) {
                  require(a <= MAX_UINT64, ERROR_NUMBER_TOO_BIG);
                  return uint64(a);
              }
          }
          
          // File: contracts/common/TimeHelpers.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract TimeHelpers {
              using Uint256Helpers for uint256;
          
              /**
              * @dev Returns the current block number.
              *      Using a function rather than `block.number` allows us to easily mock the block number in
              *      tests.
              */
              function getBlockNumber() internal view returns (uint256) {
                  return block.number;
              }
          
              /**
              * @dev Returns the current block number, converted to uint64.
              *      Using a function rather than `block.number` allows us to easily mock the block number in
              *      tests.
              */
              function getBlockNumber64() internal view returns (uint64) {
                  return getBlockNumber().toUint64();
              }
          
              /**
              * @dev Returns the current timestamp.
              *      Using a function rather than `block.timestamp` allows us to easily mock it in
              *      tests.
              */
              function getTimestamp() internal view returns (uint256) {
                  return block.timestamp; // solium-disable-line security/no-block-members
              }
          
              /**
              * @dev Returns the current timestamp, converted to uint64.
              *      Using a function rather than `block.timestamp` allows us to easily mock it in
              *      tests.
              */
              function getTimestamp64() internal view returns (uint64) {
                  return getTimestamp().toUint64();
              }
          }
          
          // File: contracts/common/UnstructuredStorage.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          library UnstructuredStorage {
              function getStorageBool(bytes32 position) internal view returns (bool data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageAddress(bytes32 position) internal view returns (address data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
                  assembly { data := sload(position) }
              }
          
              function setStorageBool(bytes32 position, bool data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageAddress(bytes32 position, address data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageBytes32(bytes32 position, bytes32 data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageUint256(bytes32 position, uint256 data) internal {
                  assembly { sstore(position, data) }
              }
          }
          
          // File: contracts/common/Initializable.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          contract Initializable is TimeHelpers {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.initializable.initializationBlock")
              bytes32 internal constant INITIALIZATION_BLOCK_POSITION = 0xebb05b386a8d34882b8711d156f463690983dc47815980fb82aeeff1aa43579e;
          
              string private constant ERROR_ALREADY_INITIALIZED = "INIT_ALREADY_INITIALIZED";
              string private constant ERROR_NOT_INITIALIZED = "INIT_NOT_INITIALIZED";
          
              modifier onlyInit {
                  require(getInitializationBlock() == 0, ERROR_ALREADY_INITIALIZED);
                  _;
              }
          
              modifier isInitialized {
                  require(hasInitialized(), ERROR_NOT_INITIALIZED);
                  _;
              }
          
              /**
              * @return Block number in which the contract was initialized
              */
              function getInitializationBlock() public view returns (uint256) {
                  return INITIALIZATION_BLOCK_POSITION.getStorageUint256();
              }
          
              /**
              * @return Whether the contract has been initialized by the time of the current block
              */
              function hasInitialized() public view returns (bool) {
                  uint256 initializationBlock = getInitializationBlock();
                  return initializationBlock != 0 && getBlockNumber() >= initializationBlock;
              }
          
              /**
              * @dev Function to be called by top level contract after initialization has finished.
              */
              function initialized() internal onlyInit {
                  INITIALIZATION_BLOCK_POSITION.setStorageUint256(getBlockNumber());
              }
          
              /**
              * @dev Function to be called by top level contract after initialization to enable the contract
              *      at a future block number rather than immediately.
              */
              function initializedAt(uint256 _blockNumber) internal onlyInit {
                  INITIALIZATION_BLOCK_POSITION.setStorageUint256(_blockNumber);
              }
          }
          
          // File: contracts/common/Petrifiable.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract Petrifiable is Initializable {
              // Use block UINT256_MAX (which should be never) as the initializable date
              uint256 internal constant PETRIFIED_BLOCK = uint256(-1);
          
              function isPetrified() public view returns (bool) {
                  return getInitializationBlock() == PETRIFIED_BLOCK;
              }
          
              /**
              * @dev Function to be called by top level contract to prevent being initialized.
              *      Useful for freezing base contracts when they're used behind proxies.
              */
              function petrify() internal onlyInit {
                  initializedAt(PETRIFIED_BLOCK);
              }
          }
          
          // File: contracts/lib/token/ERC20.sol
          
          // See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/a9f910d34f0ab33a1ae5e714f69f9596a02b4d91/contracts/token/ERC20/ERC20.sol
          
          pragma solidity ^0.4.24;
          
          
          /**
           * @title ERC20 interface
           * @dev see https://github.com/ethereum/EIPs/issues/20
           */
          contract ERC20 {
              function totalSupply() public view returns (uint256);
          
              function balanceOf(address _who) public view returns (uint256);
          
              function allowance(address _owner, address _spender)
                  public view returns (uint256);
          
              function transfer(address _to, uint256 _value) public returns (bool);
          
              function approve(address _spender, uint256 _value)
                  public returns (bool);
          
              function transferFrom(address _from, address _to, uint256 _value)
                  public returns (bool);
          
              event Transfer(
                  address indexed from,
                  address indexed to,
                  uint256 value
              );
          
              event Approval(
                  address indexed owner,
                  address indexed spender,
                  uint256 value
              );
          }
          
          // File: contracts/common/EtherTokenConstant.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          // aragonOS and aragon-apps rely on address(0) to denote native ETH, in
          // contracts where both tokens and ETH are accepted
          contract EtherTokenConstant {
              address internal constant ETH = address(0);
          }
          
          // File: contracts/common/SafeERC20.sol
          
          // Inspired by AdEx (https://github.com/AdExNetwork/adex-protocol-eth/blob/b9df617829661a7518ee10f4cb6c4108659dd6d5/contracts/libs/SafeERC20.sol)
          // and 0x (https://github.com/0xProject/0x-monorepo/blob/737d1dc54d72872e24abce5a1dbe1b66d35fa21a/contracts/protocol/contracts/protocol/AssetProxy/ERC20Proxy.sol#L143)
          
          pragma solidity ^0.4.24;
          
          
          
          library SafeERC20 {
              // Before 0.5, solidity has a mismatch between `address.transfer()` and `token.transfer()`:
              // https://github.com/ethereum/solidity/issues/3544
              bytes4 private constant TRANSFER_SELECTOR = 0xa9059cbb;
          
              string private constant ERROR_TOKEN_BALANCE_REVERTED = "SAFE_ERC_20_BALANCE_REVERTED";
              string private constant ERROR_TOKEN_ALLOWANCE_REVERTED = "SAFE_ERC_20_ALLOWANCE_REVERTED";
          
              function invokeAndCheckSuccess(address _addr, bytes memory _calldata)
                  private
                  returns (bool)
              {
                  bool ret;
                  assembly {
                      let ptr := mload(0x40)    // free memory pointer
          
                      let success := call(
                          gas,                  // forward all gas
                          _addr,                // address
                          0,                    // no value
                          add(_calldata, 0x20), // calldata start
                          mload(_calldata),     // calldata length
                          ptr,                  // write output over free memory
                          0x20                  // uint256 return
                      )
          
                      if gt(success, 0) {
                          // Check number of bytes returned from last function call
                          switch returndatasize
          
                          // No bytes returned: assume success
                          case 0 {
                              ret := 1
                          }
          
                          // 32 bytes returned: check if non-zero
                          case 0x20 {
                              // Only return success if returned data was true
                              // Already have output in ptr
                              ret := eq(mload(ptr), 1)
                          }
          
                          // Not sure what was returned: don't mark as success
                          default { }
                      }
                  }
                  return ret;
              }
          
              function staticInvoke(address _addr, bytes memory _calldata)
                  private
                  view
                  returns (bool, uint256)
              {
                  bool success;
                  uint256 ret;
                  assembly {
                      let ptr := mload(0x40)    // free memory pointer
          
                      success := staticcall(
                          gas,                  // forward all gas
                          _addr,                // address
                          add(_calldata, 0x20), // calldata start
                          mload(_calldata),     // calldata length
                          ptr,                  // write output over free memory
                          0x20                  // uint256 return
                      )
          
                      if gt(success, 0) {
                          ret := mload(ptr)
                      }
                  }
                  return (success, ret);
              }
          
              /**
              * @dev Same as a standards-compliant ERC20.transfer() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeTransfer(ERC20 _token, address _to, uint256 _amount) internal returns (bool) {
                  bytes memory transferCallData = abi.encodeWithSelector(
                      TRANSFER_SELECTOR,
                      _to,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, transferCallData);
              }
          
              /**
              * @dev Same as a standards-compliant ERC20.transferFrom() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeTransferFrom(ERC20 _token, address _from, address _to, uint256 _amount) internal returns (bool) {
                  bytes memory transferFromCallData = abi.encodeWithSelector(
                      _token.transferFrom.selector,
                      _from,
                      _to,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, transferFromCallData);
              }
          
              /**
              * @dev Same as a standards-compliant ERC20.approve() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeApprove(ERC20 _token, address _spender, uint256 _amount) internal returns (bool) {
                  bytes memory approveCallData = abi.encodeWithSelector(
                      _token.approve.selector,
                      _spender,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, approveCallData);
              }
          
              /**
              * @dev Static call into ERC20.balanceOf().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticBalanceOf(ERC20 _token, address _owner) internal view returns (uint256) {
                  bytes memory balanceOfCallData = abi.encodeWithSelector(
                      _token.balanceOf.selector,
                      _owner
                  );
          
                  (bool success, uint256 tokenBalance) = staticInvoke(_token, balanceOfCallData);
                  require(success, ERROR_TOKEN_BALANCE_REVERTED);
          
                  return tokenBalance;
              }
          
              /**
              * @dev Static call into ERC20.allowance().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticAllowance(ERC20 _token, address _owner, address _spender) internal view returns (uint256) {
                  bytes memory allowanceCallData = abi.encodeWithSelector(
                      _token.allowance.selector,
                      _owner,
                      _spender
                  );
          
                  (bool success, uint256 allowance) = staticInvoke(_token, allowanceCallData);
                  require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);
          
                  return allowance;
              }
          
              /**
              * @dev Static call into ERC20.totalSupply().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticTotalSupply(ERC20 _token) internal view returns (uint256) {
                  bytes memory totalSupplyCallData = abi.encodeWithSelector(_token.totalSupply.selector);
          
                  (bool success, uint256 totalSupply) = staticInvoke(_token, totalSupplyCallData);
                  require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);
          
                  return totalSupply;
              }
          }
          
          // File: contracts/common/VaultRecoverable.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          
          
          
          contract VaultRecoverable is IVaultRecoverable, EtherTokenConstant, IsContract {
              using SafeERC20 for ERC20;
          
              string private constant ERROR_DISALLOWED = "RECOVER_DISALLOWED";
              string private constant ERROR_VAULT_NOT_CONTRACT = "RECOVER_VAULT_NOT_CONTRACT";
              string private constant ERROR_TOKEN_TRANSFER_FAILED = "RECOVER_TOKEN_TRANSFER_FAILED";
          
              /**
               * @notice Send funds to recovery Vault. This contract should never receive funds,
               *         but in case it does, this function allows one to recover them.
               * @param _token Token balance to be sent to recovery vault.
               */
              function transferToVault(address _token) external {
                  require(allowRecoverability(_token), ERROR_DISALLOWED);
                  address vault = getRecoveryVault();
                  require(isContract(vault), ERROR_VAULT_NOT_CONTRACT);
          
                  uint256 balance;
                  if (_token == ETH) {
                      balance = address(this).balance;
                      vault.transfer(balance);
                  } else {
                      ERC20 token = ERC20(_token);
                      balance = token.staticBalanceOf(this);
                      require(token.safeTransfer(vault, balance), ERROR_TOKEN_TRANSFER_FAILED);
                  }
          
                  emit RecoverToVault(vault, _token, balance);
              }
          
              /**
              * @dev By default deriving from AragonApp makes it recoverable
              * @param token Token address that would be recovered
              * @return bool whether the app allows the recovery
              */
              function allowRecoverability(address token) public view returns (bool) {
                  return true;
              }
          
              // Cast non-implemented interface to be public so we can use it internally
              function getRecoveryVault() public view returns (address);
          }
          
          // File: contracts/apps/AppStorage.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          contract AppStorage {
              using UnstructuredStorage for bytes32;
          
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
              bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
              */
              bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
              bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;
          
              function kernel() public view returns (IKernel) {
                  return IKernel(KERNEL_POSITION.getStorageAddress());
              }
          
              function appId() public view returns (bytes32) {
                  return APP_ID_POSITION.getStorageBytes32();
              }
          
              function setKernel(IKernel _kernel) internal {
                  KERNEL_POSITION.setStorageAddress(address(_kernel));
              }
          
              function setAppId(bytes32 _appId) internal {
                  APP_ID_POSITION.setStorageBytes32(_appId);
              }
          }
          
          // File: contracts/lib/misc/ERCProxy.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract ERCProxy {
              uint256 internal constant FORWARDING = 1;
              uint256 internal constant UPGRADEABLE = 2;
          
              function proxyType() public pure returns (uint256 proxyTypeId);
              function implementation() public view returns (address codeAddr);
          }
          
          // File: contracts/common/DelegateProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract DelegateProxy is ERCProxy, IsContract {
              uint256 internal constant FWD_GAS_LIMIT = 10000;
          
              /**
              * @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
              * @param _dst Destination address to perform the delegatecall
              * @param _calldata Calldata for the delegatecall
              */
              function delegatedFwd(address _dst, bytes _calldata) internal {
                  require(isContract(_dst));
                  uint256 fwdGasLimit = FWD_GAS_LIMIT;
          
                  assembly {
                      let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
                      let size := returndatasize
                      let ptr := mload(0x40)
                      returndatacopy(ptr, 0, size)
          
                      // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
                      // if the call returned error data, forward it
                      switch result case 0 { revert(ptr, size) }
                      default { return(ptr, size) }
                  }
              }
          }
          
          // File: contracts/common/DepositableStorage.sol
          
          pragma solidity 0.4.24;
          
          
          
          contract DepositableStorage {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.depositableStorage.depositable")
              bytes32 internal constant DEPOSITABLE_POSITION = 0x665fd576fbbe6f247aff98f5c94a561e3f71ec2d3c988d56f12d342396c50cea;
          
              function isDepositable() public view returns (bool) {
                  return DEPOSITABLE_POSITION.getStorageBool();
              }
          
              function setDepositable(bool _depositable) internal {
                  DEPOSITABLE_POSITION.setStorageBool(_depositable);
              }
          }
          
          // File: contracts/common/DepositableDelegateProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract DepositableDelegateProxy is DepositableStorage, DelegateProxy {
              event ProxyDeposit(address sender, uint256 value);
          
              function () external payable {
                  uint256 forwardGasThreshold = FWD_GAS_LIMIT;
                  bytes32 isDepositablePosition = DEPOSITABLE_POSITION;
          
                  // Optimized assembly implementation to prevent EIP-1884 from breaking deposits, reference code in Solidity:
                  // https://github.com/aragon/aragonOS/blob/v4.2.1/contracts/common/DepositableDelegateProxy.sol#L10-L20
                  assembly {
                      // Continue only if the gas left is lower than the threshold for forwarding to the implementation code,
                      // otherwise continue outside of the assembly block.
                      if lt(gas, forwardGasThreshold) {
                          // Only accept the deposit and emit an event if all of the following are true:
                          // the proxy accepts deposits (isDepositable), msg.data.length == 0, and msg.value > 0
                          if and(and(sload(isDepositablePosition), iszero(calldatasize)), gt(callvalue, 0)) {
                              // Equivalent Solidity code for emitting the event:
                              // emit ProxyDeposit(msg.sender, msg.value);
          
                              let logData := mload(0x40) // free memory pointer
                              mstore(logData, caller) // add 'msg.sender' to the log data (first event param)
                              mstore(add(logData, 0x20), callvalue) // add 'msg.value' to the log data (second event param)
          
                              // Emit an event with one topic to identify the event: keccak256('ProxyDeposit(address,uint256)') = 0x15ee...dee1
                              log1(logData, 0x40, 0x15eeaa57c7bd188c1388020bcadc2c436ec60d647d36ef5b9eb3c742217ddee1)
          
                              stop() // Stop. Exits execution context
                          }
          
                          // If any of above checks failed, revert the execution (if ETH was sent, it is returned to the sender)
                          revert(0, 0)
                      }
                  }
          
                  address target = implementation();
                  delegatedFwd(target, msg.data);
              }
          }
          
          // File: contracts/apps/AppProxyBase.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          contract AppProxyBase is AppStorage, DepositableDelegateProxy, KernelNamespaceConstants {
              /**
              * @dev Initialize AppProxy
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public {
                  setKernel(_kernel);
                  setAppId(_appId);
          
                  // Implicit check that kernel is actually a Kernel
                  // The EVM doesn't actually provide a way for us to make sure, but we can force a revert to
                  // occur if the kernel is set to 0x0 or a non-code address when we try to call a method on
                  // it.
                  address appCode = getAppBase(_appId);
          
                  // If initialize payload is provided, it will be executed
                  if (_initializePayload.length > 0) {
                      require(isContract(appCode));
                      // Cannot make delegatecall as a delegateproxy.delegatedFwd as it
                      // returns ending execution context and halts contract deployment
                      require(appCode.delegatecall(_initializePayload));
                  }
              }
          
              function getAppBase(bytes32 _appId) internal view returns (address) {
                  return kernel().getApp(KERNEL_APP_BASES_NAMESPACE, _appId);
              }
          }
          
          // File: contracts/apps/AppProxyUpgradeable.sol
          
          pragma solidity 0.4.24;
          
          
          
          contract AppProxyUpgradeable is AppProxyBase {
              /**
              * @dev Initialize AppProxyUpgradeable (makes it an upgradeable Aragon app)
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
                  AppProxyBase(_kernel, _appId, _initializePayload)
                  public // solium-disable-line visibility-first
              {
                  // solium-disable-previous-line no-empty-blocks
              }
          
              /**
               * @dev ERC897, the address the proxy would delegate calls to
               */
              function implementation() public view returns (address) {
                  return getAppBase(appId());
              }
          
              /**
               * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
               */
              function proxyType() public pure returns (uint256 proxyTypeId) {
                  return UPGRADEABLE;
              }
          }
          
          // File: contracts/apps/AppProxyPinned.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          contract AppProxyPinned is IsContract, AppProxyBase {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.appStorage.pinnedCode")
              bytes32 internal constant PINNED_CODE_POSITION = 0xdee64df20d65e53d7f51cb6ab6d921a0a6a638a91e942e1d8d02df28e31c038e;
          
              /**
              * @dev Initialize AppProxyPinned (makes it an un-upgradeable Aragon app)
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
                  AppProxyBase(_kernel, _appId, _initializePayload)
                  public // solium-disable-line visibility-first
              {
                  setPinnedCode(getAppBase(_appId));
                  require(isContract(pinnedCode()));
              }
          
              /**
               * @dev ERC897, the address the proxy would delegate calls to
               */
              function implementation() public view returns (address) {
                  return pinnedCode();
              }
          
              /**
               * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
               */
              function proxyType() public pure returns (uint256 proxyTypeId) {
                  return FORWARDING;
              }
          
              function setPinnedCode(address _pinnedCode) internal {
                  PINNED_CODE_POSITION.setStorageAddress(_pinnedCode);
              }
          
              function pinnedCode() internal view returns (address) {
                  return PINNED_CODE_POSITION.getStorageAddress();
              }
          }
          
          // File: contracts/factory/AppProxyFactory.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract AppProxyFactory {
              event NewAppProxy(address proxy, bool isUpgradeable, bytes32 appId);
          
              /**
              * @notice Create a new upgradeable app instance on `_kernel` with identifier `_appId`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @return AppProxyUpgradeable
              */
              function newAppProxy(IKernel _kernel, bytes32 _appId) public returns (AppProxyUpgradeable) {
                  return newAppProxy(_kernel, _appId, new bytes(0));
              }
          
              /**
              * @notice Create a new upgradeable app instance on `_kernel` with identifier `_appId` and initialization payload `_initializePayload`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @return AppProxyUpgradeable
              */
              function newAppProxy(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public returns (AppProxyUpgradeable) {
                  AppProxyUpgradeable proxy = new AppProxyUpgradeable(_kernel, _appId, _initializePayload);
                  emit NewAppProxy(address(proxy), true, _appId);
                  return proxy;
              }
          
              /**
              * @notice Create a new pinned app instance on `_kernel` with identifier `_appId`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @return AppProxyPinned
              */
              function newAppProxyPinned(IKernel _kernel, bytes32 _appId) public returns (AppProxyPinned) {
                  return newAppProxyPinned(_kernel, _appId, new bytes(0));
              }
          
              /**
              * @notice Create a new pinned app instance on `_kernel` with identifier `_appId` and initialization payload `_initializePayload`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @param _initializePayload Proxy initialization payload
              * @return AppProxyPinned
              */
              function newAppProxyPinned(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public returns (AppProxyPinned) {
                  AppProxyPinned proxy = new AppProxyPinned(_kernel, _appId, _initializePayload);
                  emit NewAppProxy(address(proxy), false, _appId);
                  return proxy;
              }
          }
          
          // File: contracts/kernel/Kernel.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          
          
          
          
          
          
          
          // solium-disable-next-line max-len
          contract Kernel is IKernel, KernelStorage, KernelAppIds, KernelNamespaceConstants, Petrifiable, IsContract, VaultRecoverable, AppProxyFactory, ACLSyntaxSugar {
              /* Hardcoded constants to save gas
              bytes32 public constant APP_MANAGER_ROLE = keccak256("APP_MANAGER_ROLE");
              */
              bytes32 public constant APP_MANAGER_ROLE = 0xb6d92708f3d4817afc106147d969e229ced5c46e65e0a5002a0d391287762bd0;
          
              string private constant ERROR_APP_NOT_CONTRACT = "KERNEL_APP_NOT_CONTRACT";
              string private constant ERROR_INVALID_APP_CHANGE = "KERNEL_INVALID_APP_CHANGE";
              string private constant ERROR_AUTH_FAILED = "KERNEL_AUTH_FAILED";
          
              /**
              * @dev Constructor that allows the deployer to choose if the base instance should be petrified immediately.
              * @param _shouldPetrify Immediately petrify this instance so that it can never be initialized
              */
              constructor(bool _shouldPetrify) public {
                  if (_shouldPetrify) {
                      petrify();
                  }
              }
          
              /**
              * @dev Initialize can only be called once. It saves the block number in which it was initialized.
              * @notice Initialize this kernel instance along with its ACL and set `_permissionsCreator` as the entity that can create other permissions
              * @param _baseAcl Address of base ACL app
              * @param _permissionsCreator Entity that will be given permission over createPermission
              */
              function initialize(IACL _baseAcl, address _permissionsCreator) public onlyInit {
                  initialized();
          
                  // Set ACL base
                  _setApp(KERNEL_APP_BASES_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID, _baseAcl);
          
                  // Create ACL instance and attach it as the default ACL app
                  IACL acl = IACL(newAppProxy(this, KERNEL_DEFAULT_ACL_APP_ID));
                  acl.initialize(_permissionsCreator);
                  _setApp(KERNEL_APP_ADDR_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID, acl);
          
                  recoveryVaultAppId = KERNEL_DEFAULT_VAULT_APP_ID;
              }
          
              /**
              * @dev Create a new instance of an app linked to this kernel
              * @notice Create a new upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @return AppProxy instance
              */
              function newAppInstance(bytes32 _appId, address _appBase)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  return newAppInstance(_appId, _appBase, new bytes(0), false);
              }
          
              /**
              * @dev Create a new instance of an app linked to this kernel and set its base
              *      implementation if it was not already set
              * @notice Create a new upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`. `_setDefault ? 'Also sets it as the default app instance.':''`
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @param _initializePayload Payload for call made by the proxy during its construction to initialize
              * @param _setDefault Whether the app proxy app is the default one.
              *        Useful when the Kernel needs to know of an instance of a particular app,
              *        like Vault for escape hatch mechanism.
              * @return AppProxy instance
              */
              function newAppInstance(bytes32 _appId, address _appBase, bytes _initializePayload, bool _setDefault)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  _setAppIfNew(KERNEL_APP_BASES_NAMESPACE, _appId, _appBase);
                  appProxy = newAppProxy(this, _appId, _initializePayload);
                  // By calling setApp directly and not the internal functions, we make sure the params are checked
                  // and it will only succeed if sender has permissions to set something to the namespace.
                  if (_setDefault) {
                      setApp(KERNEL_APP_ADDR_NAMESPACE, _appId, appProxy);
                  }
              }
          
              /**
              * @dev Create a new pinned instance of an app linked to this kernel
              * @notice Create a new non-upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`.
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @return AppProxy instance
              */
              function newPinnedAppInstance(bytes32 _appId, address _appBase)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  return newPinnedAppInstance(_appId, _appBase, new bytes(0), false);
              }
          
              /**
              * @dev Create a new pinned instance of an app linked to this kernel and set
              *      its base implementation if it was not already set
              * @notice Create a new non-upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`. `_setDefault ? 'Also sets it as the default app instance.':''`
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @param _initializePayload Payload for call made by the proxy during its construction to initialize
              * @param _setDefault Whether the app proxy app is the default one.
              *        Useful when the Kernel needs to know of an instance of a particular app,
              *        like Vault for escape hatch mechanism.
              * @return AppProxy instance
              */
              function newPinnedAppInstance(bytes32 _appId, address _appBase, bytes _initializePayload, bool _setDefault)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  _setAppIfNew(KERNEL_APP_BASES_NAMESPACE, _appId, _appBase);
                  appProxy = newAppProxyPinned(this, _appId, _initializePayload);
                  // By calling setApp directly and not the internal functions, we make sure the params are checked
                  // and it will only succeed if sender has permissions to set something to the namespace.
                  if (_setDefault) {
                      setApp(KERNEL_APP_ADDR_NAMESPACE, _appId, appProxy);
                  }
              }
          
              /**
              * @dev Set the resolving address of an app instance or base implementation
              * @notice Set the resolving address of `_appId` in namespace `_namespace` to `_app`
              * @param _namespace App namespace to use
              * @param _appId Identifier for app
              * @param _app Address of the app instance or base implementation
              * @return ID of app
              */
              function setApp(bytes32 _namespace, bytes32 _appId, address _app)
                  public
                  auth(APP_MANAGER_ROLE, arr(_namespace, _appId))
              {
                  _setApp(_namespace, _appId, _app);
              }
          
              /**
              * @dev Set the default vault id for the escape hatch mechanism
              * @param _recoveryVaultAppId Identifier of the recovery vault app
              */
              function setRecoveryVaultAppId(bytes32 _recoveryVaultAppId)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_ADDR_NAMESPACE, _recoveryVaultAppId))
              {
                  recoveryVaultAppId = _recoveryVaultAppId;
              }
          
              // External access to default app id and namespace constants to mimic default getters for constants
              /* solium-disable function-order, mixedcase */
              function CORE_NAMESPACE() external pure returns (bytes32) { return KERNEL_CORE_NAMESPACE; }
              function APP_BASES_NAMESPACE() external pure returns (bytes32) { return KERNEL_APP_BASES_NAMESPACE; }
              function APP_ADDR_NAMESPACE() external pure returns (bytes32) { return KERNEL_APP_ADDR_NAMESPACE; }
              function KERNEL_APP_ID() external pure returns (bytes32) { return KERNEL_CORE_APP_ID; }
              function DEFAULT_ACL_APP_ID() external pure returns (bytes32) { return KERNEL_DEFAULT_ACL_APP_ID; }
              /* solium-enable function-order, mixedcase */
          
              /**
              * @dev Get the address of an app instance or base implementation
              * @param _namespace App namespace to use
              * @param _appId Identifier for app
              * @return Address of the app
              */
              function getApp(bytes32 _namespace, bytes32 _appId) public view returns (address) {
                  return apps[_namespace][_appId];
              }
          
              /**
              * @dev Get the address of the recovery Vault instance (to recover funds)
              * @return Address of the Vault
              */
              function getRecoveryVault() public view returns (address) {
                  return apps[KERNEL_APP_ADDR_NAMESPACE][recoveryVaultAppId];
              }
          
              /**
              * @dev Get the installed ACL app
              * @return ACL app
              */
              function acl() public view returns (IACL) {
                  return IACL(getApp(KERNEL_APP_ADDR_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID));
              }
          
              /**
              * @dev Function called by apps to check ACL on kernel or to check permission status
              * @param _who Sender of the original call
              * @param _where Address of the app
              * @param _what Identifier for a group of actions in app
              * @param _how Extra data for ACL auth
              * @return Boolean indicating whether the ACL allows the role or not.
              *         Always returns false if the kernel hasn't been initialized yet.
              */
              function hasPermission(address _who, address _where, bytes32 _what, bytes _how) public view returns (bool) {
                  IACL defaultAcl = acl();
                  return address(defaultAcl) != address(0) && // Poor man's initialization check (saves gas)
                      defaultAcl.hasPermission(_who, _where, _what, _how);
              }
          
              function _setApp(bytes32 _namespace, bytes32 _appId, address _app) internal {
                  require(isContract(_app), ERROR_APP_NOT_CONTRACT);
                  apps[_namespace][_appId] = _app;
                  emit SetApp(_namespace, _appId, _app);
              }
          
              function _setAppIfNew(bytes32 _namespace, bytes32 _appId, address _app) internal {
                  address app = getApp(_namespace, _appId);
                  if (app != address(0)) {
                      // The only way to set an app is if it passes the isContract check, so no need to check it again
                      require(app == _app, ERROR_INVALID_APP_CHANGE);
                  } else {
                      _setApp(_namespace, _appId, _app);
                  }
              }
          
              modifier auth(bytes32 _role, uint256[] memory _params) {
                  require(
                      hasPermission(msg.sender, address(this), _role, ConversionHelpers.dangerouslyCastUintArrayToBytes(_params)),
                      ERROR_AUTH_FAILED
                  );
                  _;
              }
          }
          
          // File: contracts/kernel/KernelProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          
          contract KernelProxy is IKernelEvents, KernelStorage, KernelAppIds, KernelNamespaceConstants, IsContract, DepositableDelegateProxy {
              /**
              * @dev KernelProxy is a proxy contract to a kernel implementation. The implementation
              *      can update the reference, which effectively upgrades the contract
              * @param _kernelImpl Address of the contract used as implementation for kernel
              */
              constructor(IKernel _kernelImpl) public {
                  require(isContract(address(_kernelImpl)));
                  apps[KERNEL_CORE_NAMESPACE][KERNEL_CORE_APP_ID] = _kernelImpl;
          
                  // Note that emitting this event is important for verifying that a KernelProxy instance
                  // was never upgraded to a malicious Kernel logic contract over its lifespan.
                  // This starts the "chain of trust", that can be followed through later SetApp() events
                  // emitted during kernel upgrades.
                  emit SetApp(KERNEL_CORE_NAMESPACE, KERNEL_CORE_APP_ID, _kernelImpl);
              }
          
              /**
               * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
               */
              function proxyType() public pure returns (uint256 proxyTypeId) {
                  return UPGRADEABLE;
              }
          
              /**
              * @dev ERC897, the address the proxy would delegate calls to
              */
              function implementation() public view returns (address) {
                  return apps[KERNEL_CORE_NAMESPACE][KERNEL_CORE_APP_ID];
              }
          }
          
          // File: contracts/common/Autopetrified.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract Autopetrified is Petrifiable {
              constructor() public {
                  // Immediately petrify base (non-proxy) instances of inherited contracts on deploy.
                  // This renders them uninitializable (and unusable without a proxy).
                  petrify();
              }
          }
          
          // File: contracts/common/ReentrancyGuard.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract ReentrancyGuard {
              using UnstructuredStorage for bytes32;
          
              /* Hardcoded constants to save gas
              bytes32 internal constant REENTRANCY_MUTEX_POSITION = keccak256("aragonOS.reentrancyGuard.mutex");
              */
              bytes32 private constant REENTRANCY_MUTEX_POSITION = 0xe855346402235fdd185c890e68d2c4ecad599b88587635ee285bce2fda58dacb;
          
              string private constant ERROR_REENTRANT = "REENTRANCY_REENTRANT_CALL";
          
              modifier nonReentrant() {
                  // Ensure mutex is unlocked
                  require(!REENTRANCY_MUTEX_POSITION.getStorageBool(), ERROR_REENTRANT);
          
                  // Lock mutex before function call
                  REENTRANCY_MUTEX_POSITION.setStorageBool(true);
          
                  // Perform function call
                  _;
          
                  // Unlock mutex after function call
                  REENTRANCY_MUTEX_POSITION.setStorageBool(false);
              }
          }
          
          // File: contracts/evmscript/IEVMScriptExecutor.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IEVMScriptExecutor {
              function execScript(bytes script, bytes input, address[] blacklist) external returns (bytes);
              function executorType() external pure returns (bytes32);
          }
          
          // File: contracts/evmscript/IEVMScriptRegistry.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract EVMScriptRegistryConstants {
              /* Hardcoded constants to save gas
              bytes32 internal constant EVMSCRIPT_REGISTRY_APP_ID = apmNamehash("evmreg");
              */
              bytes32 internal constant EVMSCRIPT_REGISTRY_APP_ID = 0xddbcfd564f642ab5627cf68b9b7d374fb4f8a36e941a75d89c87998cef03bd61;
          }
          
          
          interface IEVMScriptRegistry {
              function addScriptExecutor(IEVMScriptExecutor executor) external returns (uint id);
              function disableScriptExecutor(uint256 executorId) external;
          
              // TODO: this should be external
              // See https://github.com/ethereum/solidity/issues/4832
              function getScriptExecutor(bytes script) public view returns (IEVMScriptExecutor);
          }
          
          // File: contracts/evmscript/EVMScriptRunner.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          
          
          
          contract EVMScriptRunner is AppStorage, Initializable, EVMScriptRegistryConstants, KernelNamespaceConstants {
              string private constant ERROR_EXECUTOR_UNAVAILABLE = "EVMRUN_EXECUTOR_UNAVAILABLE";
              string private constant ERROR_PROTECTED_STATE_MODIFIED = "EVMRUN_PROTECTED_STATE_MODIFIED";
          
              /* This is manually crafted in assembly
              string private constant ERROR_EXECUTOR_INVALID_RETURN = "EVMRUN_EXECUTOR_INVALID_RETURN";
              */
          
              event ScriptResult(address indexed executor, bytes script, bytes input, bytes returnData);
          
              function getEVMScriptExecutor(bytes _script) public view returns (IEVMScriptExecutor) {
                  return IEVMScriptExecutor(getEVMScriptRegistry().getScriptExecutor(_script));
              }
          
              function getEVMScriptRegistry() public view returns (IEVMScriptRegistry) {
                  address registryAddr = kernel().getApp(KERNEL_APP_ADDR_NAMESPACE, EVMSCRIPT_REGISTRY_APP_ID);
                  return IEVMScriptRegistry(registryAddr);
              }
          
              function runScript(bytes _script, bytes _input, address[] _blacklist)
                  internal
                  isInitialized
                  protectState
                  returns (bytes)
              {
                  IEVMScriptExecutor executor = getEVMScriptExecutor(_script);
                  require(address(executor) != address(0), ERROR_EXECUTOR_UNAVAILABLE);
          
                  bytes4 sig = executor.execScript.selector;
                  bytes memory data = abi.encodeWithSelector(sig, _script, _input, _blacklist);
          
                  bytes memory output;
                  assembly {
                      let success := delegatecall(
                          gas,                // forward all gas
                          executor,           // address
                          add(data, 0x20),    // calldata start
                          mload(data),        // calldata length
                          0,                  // don't write output (we'll handle this ourselves)
                          0                   // don't write output
                      )
          
                      output := mload(0x40) // free mem ptr get
          
                      switch success
                      case 0 {
                          // If the call errored, forward its full error data
                          returndatacopy(output, 0, returndatasize)
                          revert(output, returndatasize)
                      }
                      default {
                          switch gt(returndatasize, 0x3f)
                          case 0 {
                              // Need at least 0x40 bytes returned for properly ABI-encoded bytes values,
                              // revert with "EVMRUN_EXECUTOR_INVALID_RETURN"
                              // See remix: doing a `revert("EVMRUN_EXECUTOR_INVALID_RETURN")` always results in
                              // this memory layout
                              mstore(output, 0x08c379a000000000000000000000000000000000000000000000000000000000)         // error identifier
                              mstore(add(output, 0x04), 0x0000000000000000000000000000000000000000000000000000000000000020) // starting offset
                              mstore(add(output, 0x24), 0x000000000000000000000000000000000000000000000000000000000000001e) // reason length
                              mstore(add(output, 0x44), 0x45564d52554e5f4558454355544f525f494e56414c49445f52455455524e0000) // reason
          
                              revert(output, 100) // 100 = 4 + 3 * 32 (error identifier + 3 words for the ABI encoded error)
                          }
                          default {
                              // Copy result
                              //
                              // Needs to perform an ABI decode for the expected `bytes` return type of
                              // `executor.execScript()` as solidity will automatically ABI encode the returned bytes as:
                              //    [ position of the first dynamic length return value = 0x20 (32 bytes) ]
                              //    [ output length (32 bytes) ]
                              //    [ output content (N bytes) ]
                              //
                              // Perform the ABI decode by ignoring the first 32 bytes of the return data
                              let copysize := sub(returndatasize, 0x20)
                              returndatacopy(output, 0x20, copysize)
          
                              mstore(0x40, add(output, copysize)) // free mem ptr set
                          }
                      }
                  }
          
                  emit ScriptResult(address(executor), _script, _input, output);
          
                  return output;
              }
          
              modifier protectState {
                  address preKernel = address(kernel());
                  bytes32 preAppId = appId();
                  _; // exec
                  require(address(kernel()) == preKernel, ERROR_PROTECTED_STATE_MODIFIED);
                  require(appId() == preAppId, ERROR_PROTECTED_STATE_MODIFIED);
              }
          }
          
          // File: contracts/apps/AragonApp.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          
          
          
          
          
          // Contracts inheriting from AragonApp are, by default, immediately petrified upon deployment so
          // that they can never be initialized.
          // Unless overriden, this behaviour enforces those contracts to be usable only behind an AppProxy.
          // ReentrancyGuard, EVMScriptRunner, and ACLSyntaxSugar are not directly used by this contract, but
          // are included so that they are automatically usable by subclassing contracts
          contract AragonApp is AppStorage, Autopetrified, VaultRecoverable, ReentrancyGuard, EVMScriptRunner, ACLSyntaxSugar {
              string private constant ERROR_AUTH_FAILED = "APP_AUTH_FAILED";
          
              modifier auth(bytes32 _role) {
                  require(canPerform(msg.sender, _role, new uint256[](0)), ERROR_AUTH_FAILED);
                  _;
              }
          
              modifier authP(bytes32 _role, uint256[] _params) {
                  require(canPerform(msg.sender, _role, _params), ERROR_AUTH_FAILED);
                  _;
              }
          
              /**
              * @dev Check whether an action can be performed by a sender for a particular role on this app
              * @param _sender Sender of the call
              * @param _role Role on this app
              * @param _params Permission params for the role
              * @return Boolean indicating whether the sender has the permissions to perform the action.
              *         Always returns false if the app hasn't been initialized yet.
              */
              function canPerform(address _sender, bytes32 _role, uint256[] _params) public view returns (bool) {
                  if (!hasInitialized()) {
                      return false;
                  }
          
                  IKernel linkedKernel = kernel();
                  if (address(linkedKernel) == address(0)) {
                      return false;
                  }
          
                  return linkedKernel.hasPermission(
                      _sender,
                      address(this),
                      _role,
                      ConversionHelpers.dangerouslyCastUintArrayToBytes(_params)
                  );
              }
          
              /**
              * @dev Get the recovery vault for the app
              * @return Recovery vault address for the app
              */
              function getRecoveryVault() public view returns (address) {
                  // Funds recovery via a vault is only available when used with a kernel
                  return kernel().getRecoveryVault(); // if kernel is not set, it will revert
              }
          }
          
          // File: contracts/acl/IACLOracle.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IACLOracle {
              function canPerform(address who, address where, bytes32 what, uint256[] how) external view returns (bool);
          }
          
          // File: contracts/acl/ACL.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          
          
          /* solium-disable function-order */
          // Allow public initialize() to be first
          contract ACL is IACL, TimeHelpers, AragonApp, ACLHelpers {
              /* Hardcoded constants to save gas
              bytes32 public constant CREATE_PERMISSIONS_ROLE = keccak256("CREATE_PERMISSIONS_ROLE");
              */
              bytes32 public constant CREATE_PERMISSIONS_ROLE = 0x0b719b33c83b8e5d300c521cb8b54ae9bd933996a14bef8c2f4e0285d2d2400a;
          
              enum Op { NONE, EQ, NEQ, GT, LT, GTE, LTE, RET, NOT, AND, OR, XOR, IF_ELSE } // op types
          
              struct Param {
                  uint8 id;
                  uint8 op;
                  uint240 value; // even though value is an uint240 it can store addresses
                  // in the case of 32 byte hashes losing 2 bytes precision isn't a huge deal
                  // op and id take less than 1 byte each so it can be kept in 1 sstore
              }
          
              uint8 internal constant BLOCK_NUMBER_PARAM_ID = 200;
              uint8 internal constant TIMESTAMP_PARAM_ID    = 201;
              // 202 is unused
              uint8 internal constant ORACLE_PARAM_ID       = 203;
              uint8 internal constant LOGIC_OP_PARAM_ID     = 204;
              uint8 internal constant PARAM_VALUE_PARAM_ID  = 205;
              // TODO: Add execution times param type?
          
              /* Hardcoded constant to save gas
              bytes32 public constant EMPTY_PARAM_HASH = keccak256(uint256(0));
              */
              bytes32 public constant EMPTY_PARAM_HASH = 0x290decd9548b62a8d60345a988386fc84ba6bc95484008f6362f93160ef3e563;
              bytes32 public constant NO_PERMISSION = bytes32(0);
              address public constant ANY_ENTITY = address(-1);
              address public constant BURN_ENTITY = address(1); // address(0) is already used as "no permission manager"
          
              string private constant ERROR_AUTH_INIT_KERNEL = "ACL_AUTH_INIT_KERNEL";
              string private constant ERROR_AUTH_NO_MANAGER = "ACL_AUTH_NO_MANAGER";
              string private constant ERROR_EXISTENT_MANAGER = "ACL_EXISTENT_MANAGER";
          
              // Whether someone has a permission
              mapping (bytes32 => bytes32) internal permissions; // permissions hash => params hash
              mapping (bytes32 => Param[]) internal permissionParams; // params hash => params
          
              // Who is the manager of a permission
              mapping (bytes32 => address) internal permissionManager;
          
              event SetPermission(address indexed entity, address indexed app, bytes32 indexed role, bool allowed);
              event SetPermissionParams(address indexed entity, address indexed app, bytes32 indexed role, bytes32 paramsHash);
              event ChangePermissionManager(address indexed app, bytes32 indexed role, address indexed manager);
          
              modifier onlyPermissionManager(address _app, bytes32 _role) {
                  require(msg.sender == getPermissionManager(_app, _role), ERROR_AUTH_NO_MANAGER);
                  _;
              }
          
              modifier noPermissionManager(address _app, bytes32 _role) {
                  // only allow permission creation (or re-creation) when there is no manager
                  require(getPermissionManager(_app, _role) == address(0), ERROR_EXISTENT_MANAGER);
                  _;
              }
          
              /**
              * @dev Initialize can only be called once. It saves the block number in which it was initialized.
              * @notice Initialize an ACL instance and set `_permissionsCreator` as the entity that can create other permissions
              * @param _permissionsCreator Entity that will be given permission over createPermission
              */
              function initialize(address _permissionsCreator) public onlyInit {
                  initialized();
                  require(msg.sender == address(kernel()), ERROR_AUTH_INIT_KERNEL);
          
                  _createPermission(_permissionsCreator, this, CREATE_PERMISSIONS_ROLE, _permissionsCreator);
              }
          
              /**
              * @dev Creates a permission that wasn't previously set and managed.
              *      If a created permission is removed it is possible to reset it with createPermission.
              *      This is the **ONLY** way to create permissions and set managers to permissions that don't
              *      have a manager.
              *      In terms of the ACL being initialized, this function implicitly protects all the other
              *      state-changing external functions, as they all require the sender to be a manager.
              * @notice Create a new permission granting `_entity` the ability to perform actions requiring `_role` on `_app`, setting `_manager` as the permission's manager
              * @param _entity Address of the whitelisted entity that will be able to perform the role
              * @param _app Address of the app in which the role will be allowed (requires app to depend on kernel for ACL)
              * @param _role Identifier for the group of actions in app given access to perform
              * @param _manager Address of the entity that will be able to grant and revoke the permission further.
              */
              function createPermission(address _entity, address _app, bytes32 _role, address _manager)
                  external
                  auth(CREATE_PERMISSIONS_ROLE)
                  noPermissionManager(_app, _role)
              {
                  _createPermission(_entity, _app, _role, _manager);
              }
          
              /**
              * @dev Grants permission if allowed. This requires `msg.sender` to be the permission manager
              * @notice Grant `_entity` the ability to perform actions requiring `_role` on `_app`
              * @param _entity Address of the whitelisted entity that will be able to perform the role
              * @param _app Address of the app in which the role will be allowed (requires app to depend on kernel for ACL)
              * @param _role Identifier for the group of actions in app given access to perform
              */
              function grantPermission(address _entity, address _app, bytes32 _role)
                  external
              {
                  grantPermissionP(_entity, _app, _role, new uint256[](0));
              }
          
              /**
              * @dev Grants a permission with parameters if allowed. This requires `msg.sender` to be the permission manager
              * @notice Grant `_entity` the ability to perform actions requiring `_role` on `_app`
              * @param _entity Address of the whitelisted entity that will be able to perform the role
              * @param _app Address of the app in which the role will be allowed (requires app to depend on kernel for ACL)
              * @param _role Identifier for the group of actions in app given access to perform
              * @param _params Permission parameters
              */
              function grantPermissionP(address _entity, address _app, bytes32 _role, uint256[] _params)
                  public
                  onlyPermissionManager(_app, _role)
              {
                  bytes32 paramsHash = _params.length > 0 ? _saveParams(_params) : EMPTY_PARAM_HASH;
                  _setPermission(_entity, _app, _role, paramsHash);
              }
          
              /**
              * @dev Revokes permission if allowed. This requires `msg.sender` to be the the permission manager
              * @notice Revoke from `_entity` the ability to perform actions requiring `_role` on `_app`
              * @param _entity Address of the whitelisted entity to revoke access from
              * @param _app Address of the app in which the role will be revoked
              * @param _role Identifier for the group of actions in app being revoked
              */
              function revokePermission(address _entity, address _app, bytes32 _role)
                  external
                  onlyPermissionManager(_app, _role)
              {
                  _setPermission(_entity, _app, _role, NO_PERMISSION);
              }
          
              /**
              * @notice Set `_newManager` as the manager of `_role` in `_app`
              * @param _newManager Address for the new manager
              * @param _app Address of the app in which the permission management is being transferred
              * @param _role Identifier for the group of actions being transferred
              */
              function setPermissionManager(address _newManager, address _app, bytes32 _role)
                  external
                  onlyPermissionManager(_app, _role)
              {
                  _setPermissionManager(_newManager, _app, _role);
              }
          
              /**
              * @notice Remove the manager of `_role` in `_app`
              * @param _app Address of the app in which the permission is being unmanaged
              * @param _role Identifier for the group of actions being unmanaged
              */
              function removePermissionManager(address _app, bytes32 _role)
                  external
                  onlyPermissionManager(_app, _role)
              {
                  _setPermissionManager(address(0), _app, _role);
              }
          
              /**
              * @notice Burn non-existent `_role` in `_app`, so no modification can be made to it (grant, revoke, permission manager)
              * @param _app Address of the app in which the permission is being burned
              * @param _role Identifier for the group of actions being burned
              */
              function createBurnedPermission(address _app, bytes32 _role)
                  external
                  auth(CREATE_PERMISSIONS_ROLE)
                  noPermissionManager(_app, _role)
              {
                  _setPermissionManager(BURN_ENTITY, _app, _role);
              }
          
              /**
              * @notice Burn `_role` in `_app`, so no modification can be made to it (grant, revoke, permission manager)
              * @param _app Address of the app in which the permission is being burned
              * @param _role Identifier for the group of actions being burned
              */
              function burnPermissionManager(address _app, bytes32 _role)
                  external
                  onlyPermissionManager(_app, _role)
              {
                  _setPermissionManager(BURN_ENTITY, _app, _role);
              }
          
              /**
               * @notice Get parameters for permission array length
               * @param _entity Address of the whitelisted entity that will be able to perform the role
               * @param _app Address of the app
               * @param _role Identifier for a group of actions in app
               * @return Length of the array
               */
              function getPermissionParamsLength(address _entity, address _app, bytes32 _role) external view returns (uint) {
                  return permissionParams[permissions[permissionHash(_entity, _app, _role)]].length;
              }
          
              /**
              * @notice Get parameter for permission
              * @param _entity Address of the whitelisted entity that will be able to perform the role
              * @param _app Address of the app
              * @param _role Identifier for a group of actions in app
              * @param _index Index of parameter in the array
              * @return Parameter (id, op, value)
              */
              function getPermissionParam(address _entity, address _app, bytes32 _role, uint _index)
                  external
                  view
                  returns (uint8, uint8, uint240)
              {
                  Param storage param = permissionParams[permissions[permissionHash(_entity, _app, _role)]][_index];
                  return (param.id, param.op, param.value);
              }
          
              /**
              * @dev Get manager for permission
              * @param _app Address of the app
              * @param _role Identifier for a group of actions in app
              * @return address of the manager for the permission
              */
              function getPermissionManager(address _app, bytes32 _role) public view returns (address) {
                  return permissionManager[roleHash(_app, _role)];
              }
          
              /**
              * @dev Function called by apps to check ACL on kernel or to check permission statu
              * @param _who Sender of the original call
              * @param _where Address of the app
              * @param _where Identifier for a group of actions in app
              * @param _how Permission parameters
              * @return boolean indicating whether the ACL allows the role or not
              */
              function hasPermission(address _who, address _where, bytes32 _what, bytes memory _how) public view returns (bool) {
                  return hasPermission(_who, _where, _what, ConversionHelpers.dangerouslyCastBytesToUintArray(_how));
              }
          
              function hasPermission(address _who, address _where, bytes32 _what, uint256[] memory _how) public view returns (bool) {
                  bytes32 whoParams = permissions[permissionHash(_who, _where, _what)];
                  if (whoParams != NO_PERMISSION && evalParams(whoParams, _who, _where, _what, _how)) {
                      return true;
                  }
          
                  bytes32 anyParams = permissions[permissionHash(ANY_ENTITY, _where, _what)];
                  if (anyParams != NO_PERMISSION && evalParams(anyParams, ANY_ENTITY, _where, _what, _how)) {
                      return true;
                  }
          
                  return false;
              }
          
              function hasPermission(address _who, address _where, bytes32 _what) public view returns (bool) {
                  uint256[] memory empty = new uint256[](0);
                  return hasPermission(_who, _where, _what, empty);
              }
          
              function evalParams(
                  bytes32 _paramsHash,
                  address _who,
                  address _where,
                  bytes32 _what,
                  uint256[] _how
              ) public view returns (bool)
              {
                  if (_paramsHash == EMPTY_PARAM_HASH) {
                      return true;
                  }
          
                  return _evalParam(_paramsHash, 0, _who, _where, _what, _how);
              }
          
              /**
              * @dev Internal createPermission for access inside the kernel (on instantiation)
              */
              function _createPermission(address _entity, address _app, bytes32 _role, address _manager) internal {
                  _setPermission(_entity, _app, _role, EMPTY_PARAM_HASH);
                  _setPermissionManager(_manager, _app, _role);
              }
          
              /**
              * @dev Internal function called to actually save the permission
              */
              function _setPermission(address _entity, address _app, bytes32 _role, bytes32 _paramsHash) internal {
                  permissions[permissionHash(_entity, _app, _role)] = _paramsHash;
                  bool entityHasPermission = _paramsHash != NO_PERMISSION;
                  bool permissionHasParams = entityHasPermission && _paramsHash != EMPTY_PARAM_HASH;
          
                  emit SetPermission(_entity, _app, _role, entityHasPermission);
                  if (permissionHasParams) {
                      emit SetPermissionParams(_entity, _app, _role, _paramsHash);
                  }
              }
          
              function _saveParams(uint256[] _encodedParams) internal returns (bytes32) {
                  bytes32 paramHash = keccak256(abi.encodePacked(_encodedParams));
                  Param[] storage params = permissionParams[paramHash];
          
                  if (params.length == 0) { // params not saved before
                      for (uint256 i = 0; i < _encodedParams.length; i++) {
                          uint256 encodedParam = _encodedParams[i];
                          Param memory param = Param(decodeParamId(encodedParam), decodeParamOp(encodedParam), uint240(encodedParam));
                          params.push(param);
                      }
                  }
          
                  return paramHash;
              }
          
              function _evalParam(
                  bytes32 _paramsHash,
                  uint32 _paramId,
                  address _who,
                  address _where,
                  bytes32 _what,
                  uint256[] _how
              ) internal view returns (bool)
              {
                  if (_paramId >= permissionParams[_paramsHash].length) {
                      return false; // out of bounds
                  }
          
                  Param memory param = permissionParams[_paramsHash][_paramId];
          
                  if (param.id == LOGIC_OP_PARAM_ID) {
                      return _evalLogic(param, _paramsHash, _who, _where, _what, _how);
                  }
          
                  uint256 value;
                  uint256 comparedTo = uint256(param.value);
          
                  // get value
                  if (param.id == ORACLE_PARAM_ID) {
                      value = checkOracle(IACLOracle(param.value), _who, _where, _what, _how) ? 1 : 0;
                      comparedTo = 1;
                  } else if (param.id == BLOCK_NUMBER_PARAM_ID) {
                      value = getBlockNumber();
                  } else if (param.id == TIMESTAMP_PARAM_ID) {
                      value = getTimestamp();
                  } else if (param.id == PARAM_VALUE_PARAM_ID) {
                      value = uint256(param.value);
                  } else {
                      if (param.id >= _how.length) {
                          return false;
                      }
                      value = uint256(uint240(_how[param.id])); // force lost precision
                  }
          
                  if (Op(param.op) == Op.RET) {
                      return uint256(value) > 0;
                  }
          
                  return compare(value, Op(param.op), comparedTo);
              }
          
              function _evalLogic(Param _param, bytes32 _paramsHash, address _who, address _where, bytes32 _what, uint256[] _how)
                  internal
                  view
                  returns (bool)
              {
                  if (Op(_param.op) == Op.IF_ELSE) {
                      uint32 conditionParam;
                      uint32 successParam;
                      uint32 failureParam;
          
                      (conditionParam, successParam, failureParam) = decodeParamsList(uint256(_param.value));
                      bool result = _evalParam(_paramsHash, conditionParam, _who, _where, _what, _how);
          
                      return _evalParam(_paramsHash, result ? successParam : failureParam, _who, _where, _what, _how);
                  }
          
                  uint32 param1;
                  uint32 param2;
          
                  (param1, param2,) = decodeParamsList(uint256(_param.value));
                  bool r1 = _evalParam(_paramsHash, param1, _who, _where, _what, _how);
          
                  if (Op(_param.op) == Op.NOT) {
                      return !r1;
                  }
          
                  if (r1 && Op(_param.op) == Op.OR) {
                      return true;
                  }
          
                  if (!r1 && Op(_param.op) == Op.AND) {
                      return false;
                  }
          
                  bool r2 = _evalParam(_paramsHash, param2, _who, _where, _what, _how);
          
                  if (Op(_param.op) == Op.XOR) {
                      return r1 != r2;
                  }
          
                  return r2; // both or and and depend on result of r2 after checks
              }
          
              function compare(uint256 _a, Op _op, uint256 _b) internal pure returns (bool) {
                  if (_op == Op.EQ)  return _a == _b;                              // solium-disable-line lbrace
                  if (_op == Op.NEQ) return _a != _b;                              // solium-disable-line lbrace
                  if (_op == Op.GT)  return _a > _b;                               // solium-disable-line lbrace
                  if (_op == Op.LT)  return _a < _b;                               // solium-disable-line lbrace
                  if (_op == Op.GTE) return _a >= _b;                              // solium-disable-line lbrace
                  if (_op == Op.LTE) return _a <= _b;                              // solium-disable-line lbrace
                  return false;
              }
          
              function checkOracle(IACLOracle _oracleAddr, address _who, address _where, bytes32 _what, uint256[] _how) internal view returns (bool) {
                  bytes4 sig = _oracleAddr.canPerform.selector;
          
                  // a raw call is required so we can return false if the call reverts, rather than reverting
                  bytes memory checkCalldata = abi.encodeWithSelector(sig, _who, _where, _what, _how);
          
                  bool ok;
                  assembly {
                      // send all available gas; if the oracle eats up all the gas, we will eventually revert
                      // note that we are currently guaranteed to still have some gas after the call from
                      // EIP-150's 63/64 gas forward rule
                      ok := staticcall(gas, _oracleAddr, add(checkCalldata, 0x20), mload(checkCalldata), 0, 0)
                  }
          
                  if (!ok) {
                      return false;
                  }
          
                  uint256 size;
                  assembly { size := returndatasize }
                  if (size != 32) {
                      return false;
                  }
          
                  bool result;
                  assembly {
                      let ptr := mload(0x40)       // get next free memory ptr
                      returndatacopy(ptr, 0, size) // copy return from above `staticcall`
                      result := mload(ptr)         // read data at ptr and set it to result
                      mstore(ptr, 0)               // set pointer memory to 0 so it still is the next free ptr
                  }
          
                  return result;
              }
          
              /**
              * @dev Internal function that sets management
              */
              function _setPermissionManager(address _newManager, address _app, bytes32 _role) internal {
                  permissionManager[roleHash(_app, _role)] = _newManager;
                  emit ChangePermissionManager(_app, _role, _newManager);
              }
          
              function roleHash(address _where, bytes32 _what) internal pure returns (bytes32) {
                  return keccak256(abi.encodePacked("ROLE", _where, _what));
              }
          
              function permissionHash(address _who, address _where, bytes32 _what) internal pure returns (bytes32) {
                  return keccak256(abi.encodePacked("PERMISSION", _who, _where, _what));
              }
          }
          
          // File: contracts/evmscript/ScriptHelpers.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          library ScriptHelpers {
              function getSpecId(bytes _script) internal pure returns (uint32) {
                  return uint32At(_script, 0);
              }
          
              function uint256At(bytes _data, uint256 _location) internal pure returns (uint256 result) {
                  assembly {
                      result := mload(add(_data, add(0x20, _location)))
                  }
              }
          
              function addressAt(bytes _data, uint256 _location) internal pure returns (address result) {
                  uint256 word = uint256At(_data, _location);
          
                  assembly {
                      result := div(and(word, 0xffffffffffffffffffffffffffffffffffffffff000000000000000000000000),
                      0x1000000000000000000000000)
                  }
              }
          
              function uint32At(bytes _data, uint256 _location) internal pure returns (uint32 result) {
                  uint256 word = uint256At(_data, _location);
          
                  assembly {
                      result := div(and(word, 0xffffffff00000000000000000000000000000000000000000000000000000000),
                      0x100000000000000000000000000000000000000000000000000000000)
                  }
              }
          
              function locationOf(bytes _data, uint256 _location) internal pure returns (uint256 result) {
                  assembly {
                      result := add(_data, add(0x20, _location))
                  }
              }
          
              function toBytes(bytes4 _sig) internal pure returns (bytes) {
                  bytes memory payload = new bytes(4);
                  assembly { mstore(add(payload, 0x20), _sig) }
                  return payload;
              }
          }
          
          // File: contracts/evmscript/EVMScriptRegistry.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          /* solium-disable function-order */
          // Allow public initialize() to be first
          contract EVMScriptRegistry is IEVMScriptRegistry, EVMScriptRegistryConstants, AragonApp {
              using ScriptHelpers for bytes;
          
              /* Hardcoded constants to save gas
              bytes32 public constant REGISTRY_ADD_EXECUTOR_ROLE = keccak256("REGISTRY_ADD_EXECUTOR_ROLE");
              bytes32 public constant REGISTRY_MANAGER_ROLE = keccak256("REGISTRY_MANAGER_ROLE");
              */
              bytes32 public constant REGISTRY_ADD_EXECUTOR_ROLE = 0xc4e90f38eea8c4212a009ca7b8947943ba4d4a58d19b683417f65291d1cd9ed2;
              // WARN: Manager can censor all votes and the like happening in an org
              bytes32 public constant REGISTRY_MANAGER_ROLE = 0xf7a450ef335e1892cb42c8ca72e7242359d7711924b75db5717410da3f614aa3;
          
              uint256 internal constant SCRIPT_START_LOCATION = 4;
          
              string private constant ERROR_INEXISTENT_EXECUTOR = "EVMREG_INEXISTENT_EXECUTOR";
              string private constant ERROR_EXECUTOR_ENABLED = "EVMREG_EXECUTOR_ENABLED";
              string private constant ERROR_EXECUTOR_DISABLED = "EVMREG_EXECUTOR_DISABLED";
              string private constant ERROR_SCRIPT_LENGTH_TOO_SHORT = "EVMREG_SCRIPT_LENGTH_TOO_SHORT";
          
              struct ExecutorEntry {
                  IEVMScriptExecutor executor;
                  bool enabled;
              }
          
              uint256 private executorsNextIndex;
              mapping (uint256 => ExecutorEntry) public executors;
          
              event EnableExecutor(uint256 indexed executorId, address indexed executorAddress);
              event DisableExecutor(uint256 indexed executorId, address indexed executorAddress);
          
              modifier executorExists(uint256 _executorId) {
                  require(_executorId > 0 && _executorId < executorsNextIndex, ERROR_INEXISTENT_EXECUTOR);
                  _;
              }
          
              /**
              * @notice Initialize the registry
              */
              function initialize() public onlyInit {
                  initialized();
                  // Create empty record to begin executor IDs at 1
                  executorsNextIndex = 1;
              }
          
              /**
              * @notice Add a new script executor with address `_executor` to the registry
              * @param _executor Address of the IEVMScriptExecutor that will be added to the registry
              * @return id Identifier of the executor in the registry
              */
              function addScriptExecutor(IEVMScriptExecutor _executor) external auth(REGISTRY_ADD_EXECUTOR_ROLE) returns (uint256 id) {
                  uint256 executorId = executorsNextIndex++;
                  executors[executorId] = ExecutorEntry(_executor, true);
                  emit EnableExecutor(executorId, _executor);
                  return executorId;
              }
          
              /**
              * @notice Disable script executor with ID `_executorId`
              * @param _executorId Identifier of the executor in the registry
              */
              function disableScriptExecutor(uint256 _executorId)
                  external
                  authP(REGISTRY_MANAGER_ROLE, arr(_executorId))
              {
                  // Note that we don't need to check for an executor's existence in this case, as only
                  // existing executors can be enabled
                  ExecutorEntry storage executorEntry = executors[_executorId];
                  require(executorEntry.enabled, ERROR_EXECUTOR_DISABLED);
                  executorEntry.enabled = false;
                  emit DisableExecutor(_executorId, executorEntry.executor);
              }
          
              /**
              * @notice Enable script executor with ID `_executorId`
              * @param _executorId Identifier of the executor in the registry
              */
              function enableScriptExecutor(uint256 _executorId)
                  external
                  authP(REGISTRY_MANAGER_ROLE, arr(_executorId))
                  executorExists(_executorId)
              {
                  ExecutorEntry storage executorEntry = executors[_executorId];
                  require(!executorEntry.enabled, ERROR_EXECUTOR_ENABLED);
                  executorEntry.enabled = true;
                  emit EnableExecutor(_executorId, executorEntry.executor);
              }
          
              /**
              * @dev Get the script executor that can execute a particular script based on its first 4 bytes
              * @param _script EVMScript being inspected
              */
              function getScriptExecutor(bytes _script) public view returns (IEVMScriptExecutor) {
                  require(_script.length >= SCRIPT_START_LOCATION, ERROR_SCRIPT_LENGTH_TOO_SHORT);
                  uint256 id = _script.getSpecId();
          
                  // Note that we don't need to check for an executor's existence in this case, as only
                  // existing executors can be enabled
                  ExecutorEntry storage entry = executors[id];
                  return entry.enabled ? entry.executor : IEVMScriptExecutor(0);
              }
          }
          
          // File: contracts/evmscript/executors/BaseEVMScriptExecutor.sol
          
          /*
           * SPDX-License-Identifier:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          contract BaseEVMScriptExecutor is IEVMScriptExecutor, Autopetrified {
              uint256 internal constant SCRIPT_START_LOCATION = 4;
          }
          
          // File: contracts/evmscript/executors/CallsScript.sol
          
          pragma solidity 0.4.24;
          
          // Inspired by https://github.com/reverendus/tx-manager
          
          
          
          
          contract CallsScript is BaseEVMScriptExecutor {
              using ScriptHelpers for bytes;
          
              /* Hardcoded constants to save gas
              bytes32 internal constant EXECUTOR_TYPE = keccak256("CALLS_SCRIPT");
              */
              bytes32 internal constant EXECUTOR_TYPE = 0x2dc858a00f3e417be1394b87c07158e989ec681ce8cc68a9093680ac1a870302;
          
              string private constant ERROR_BLACKLISTED_CALL = "EVMCALLS_BLACKLISTED_CALL";
              string private constant ERROR_INVALID_LENGTH = "EVMCALLS_INVALID_LENGTH";
          
              /* This is manually crafted in assembly
              string private constant ERROR_CALL_REVERTED = "EVMCALLS_CALL_REVERTED";
              */
          
              event LogScriptCall(address indexed sender, address indexed src, address indexed dst);
          
              /**
              * @notice Executes a number of call scripts
              * @param _script [ specId (uint32) ] many calls with this structure ->
              *    [ to (address: 20 bytes) ] [ calldataLength (uint32: 4 bytes) ] [ calldata (calldataLength bytes) ]
              * @param _blacklist Addresses the script cannot call to, or will revert.
              * @return Always returns empty byte array
              */
              function execScript(bytes _script, bytes, address[] _blacklist) external isInitialized returns (bytes) {
                  uint256 location = SCRIPT_START_LOCATION; // first 32 bits are spec id
                  while (location < _script.length) {
                      // Check there's at least address + calldataLength available
                      require(_script.length - location >= 0x18, ERROR_INVALID_LENGTH);
          
                      address contractAddress = _script.addressAt(location);
                      // Check address being called is not blacklist
                      for (uint256 i = 0; i < _blacklist.length; i++) {
                          require(contractAddress != _blacklist[i], ERROR_BLACKLISTED_CALL);
                      }
          
                      // logged before execution to ensure event ordering in receipt
                      // if failed entire execution is reverted regardless
                      emit LogScriptCall(msg.sender, address(this), contractAddress);
          
                      uint256 calldataLength = uint256(_script.uint32At(location + 0x14));
                      uint256 startOffset = location + 0x14 + 0x04;
                      uint256 calldataStart = _script.locationOf(startOffset);
          
                      // compute end of script / next location
                      location = startOffset + calldataLength;
                      require(location <= _script.length, ERROR_INVALID_LENGTH);
          
                      bool success;
                      assembly {
                          success := call(
                              sub(gas, 5000),       // forward gas left - 5000
                              contractAddress,      // address
                              0,                    // no value
                              calldataStart,        // calldata start
                              calldataLength,       // calldata length
                              0,                    // don't write output
                              0                     // don't write output
                          )
          
                          switch success
                          case 0 {
                              let ptr := mload(0x40)
          
                              switch returndatasize
                              case 0 {
                                  // No error data was returned, revert with "EVMCALLS_CALL_REVERTED"
                                  // See remix: doing a `revert("EVMCALLS_CALL_REVERTED")` always results in
                                  // this memory layout
                                  mstore(ptr, 0x08c379a000000000000000000000000000000000000000000000000000000000)         // error identifier
                                  mstore(add(ptr, 0x04), 0x0000000000000000000000000000000000000000000000000000000000000020) // starting offset
                                  mstore(add(ptr, 0x24), 0x0000000000000000000000000000000000000000000000000000000000000016) // reason length
                                  mstore(add(ptr, 0x44), 0x45564d43414c4c535f43414c4c5f524556455254454400000000000000000000) // reason
          
                                  revert(ptr, 100) // 100 = 4 + 3 * 32 (error identifier + 3 words for the ABI encoded error)
                              }
                              default {
                                  // Forward the full error data
                                  returndatacopy(ptr, 0, returndatasize)
                                  revert(ptr, returndatasize)
                              }
                          }
                          default { }
                      }
                  }
                  // No need to allocate empty bytes for the return as this can only be called via an delegatecall
                  // (due to the isInitialized modifier)
              }
          
              function executorType() external pure returns (bytes32) {
                  return EXECUTOR_TYPE;
              }
          }
          
          // File: contracts/factory/EVMScriptRegistryFactory.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          
          contract EVMScriptRegistryFactory is EVMScriptRegistryConstants {
              EVMScriptRegistry public baseReg;
              IEVMScriptExecutor public baseCallScript;
          
              /**
              * @notice Create a new EVMScriptRegistryFactory.
              */
              constructor() public {
                  baseReg = new EVMScriptRegistry();
                  baseCallScript = IEVMScriptExecutor(new CallsScript());
              }
          
              /**
              * @notice Install a new pinned instance of EVMScriptRegistry on `_dao`.
              * @param _dao Kernel
              * @return Installed EVMScriptRegistry
              */
              function newEVMScriptRegistry(Kernel _dao) public returns (EVMScriptRegistry reg) {
                  bytes memory initPayload = abi.encodeWithSelector(reg.initialize.selector);
                  reg = EVMScriptRegistry(_dao.newPinnedAppInstance(EVMSCRIPT_REGISTRY_APP_ID, baseReg, initPayload, true));
          
                  ACL acl = ACL(_dao.acl());
          
                  acl.createPermission(this, reg, reg.REGISTRY_ADD_EXECUTOR_ROLE(), this);
          
                  reg.addScriptExecutor(baseCallScript);     // spec 1 = CallsScript
          
                  // Clean up the permissions
                  acl.revokePermission(this, reg, reg.REGISTRY_ADD_EXECUTOR_ROLE());
                  acl.removePermissionManager(reg, reg.REGISTRY_ADD_EXECUTOR_ROLE());
          
                  return reg;
              }
          }
          
          // File: contracts/factory/DAOFactory.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          
          
          contract DAOFactory {
              IKernel public baseKernel;
              IACL public baseACL;
              EVMScriptRegistryFactory public regFactory;
          
              event DeployDAO(address dao);
              event DeployEVMScriptRegistry(address reg);
          
              /**
              * @notice Create a new DAOFactory, creating DAOs with Kernels proxied to `_baseKernel`, ACLs proxied to `_baseACL`, and new EVMScriptRegistries created from `_regFactory`.
              * @param _baseKernel Base Kernel
              * @param _baseACL Base ACL
              * @param _regFactory EVMScriptRegistry factory
              */
              constructor(IKernel _baseKernel, IACL _baseACL, EVMScriptRegistryFactory _regFactory) public {
                  // No need to init as it cannot be killed by devops199
                  if (address(_regFactory) != address(0)) {
                      regFactory = _regFactory;
                  }
          
                  baseKernel = _baseKernel;
                  baseACL = _baseACL;
              }
          
              /**
              * @notice Create a new DAO with `_root` set as the initial admin
              * @param _root Address that will be granted control to setup DAO permissions
              * @return Newly created DAO
              */
              function newDAO(address _root) public returns (Kernel) {
                  Kernel dao = Kernel(new KernelProxy(baseKernel));
          
                  if (address(regFactory) == address(0)) {
                      dao.initialize(baseACL, _root);
                  } else {
                      dao.initialize(baseACL, this);
          
                      ACL acl = ACL(dao.acl());
                      bytes32 permRole = acl.CREATE_PERMISSIONS_ROLE();
                      bytes32 appManagerRole = dao.APP_MANAGER_ROLE();
          
                      acl.grantPermission(regFactory, acl, permRole);
          
                      acl.createPermission(regFactory, dao, appManagerRole, this);
          
                      EVMScriptRegistry reg = regFactory.newEVMScriptRegistry(dao);
                      emit DeployEVMScriptRegistry(address(reg));
          
                      // Clean up permissions
                      // First, completely reset the APP_MANAGER_ROLE
                      acl.revokePermission(regFactory, dao, appManagerRole);
                      acl.removePermissionManager(dao, appManagerRole);
          
                      // Then, make root the only holder and manager of CREATE_PERMISSIONS_ROLE
                      acl.revokePermission(regFactory, acl, permRole);
                      acl.revokePermission(this, acl, permRole);
                      acl.grantPermission(_root, acl, permRole);
                      acl.setPermissionManager(_root, acl, permRole);
                  }
          
                  emit DeployDAO(address(dao));
          
                  return dao;
              }
          }

          File 5 of 6: Kernel
          // File: contracts/acl/IACL.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IACL {
              function initialize(address permissionsCreator) external;
          
              // TODO: this should be external
              // See https://github.com/ethereum/solidity/issues/4832
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          }
          
          // File: contracts/common/IVaultRecoverable.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          interface IVaultRecoverable {
              event RecoverToVault(address indexed vault, address indexed token, uint256 amount);
          
              function transferToVault(address token) external;
          
              function allowRecoverability(address token) external view returns (bool);
              function getRecoveryVault() external view returns (address);
          }
          
          // File: contracts/kernel/IKernel.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          interface IKernelEvents {
              event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
          }
          
          
          // This should be an interface, but interfaces can't inherit yet :(
          contract IKernel is IKernelEvents, IVaultRecoverable {
              function acl() public view returns (IACL);
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          
              function setApp(bytes32 namespace, bytes32 appId, address app) public;
              function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
          }
          
          // File: contracts/kernel/KernelConstants.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract KernelAppIds {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
              */
              bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
          }
          
          
          contract KernelNamespaceConstants {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
              */
              bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
          }
          
          // File: contracts/kernel/KernelStorage.sol
          
          pragma solidity 0.4.24;
          
          
          contract KernelStorage {
              // namespace => app id => address
              mapping (bytes32 => mapping (bytes32 => address)) public apps;
              bytes32 public recoveryVaultAppId;
          }
          
          // File: contracts/acl/ACLSyntaxSugar.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract ACLSyntaxSugar {
              function arr() internal pure returns (uint256[]) {
                  return new uint256[](0);
              }
          
              function arr(bytes32 _a) internal pure returns (uint256[] r) {
                  return arr(uint256(_a));
              }
          
              function arr(bytes32 _a, bytes32 _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
          
              function arr(address _a) internal pure returns (uint256[] r) {
                  return arr(uint256(_a));
              }
          
              function arr(address _a, address _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
          
              function arr(address _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), _b, _c);
              }
          
              function arr(address _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), _b, _c, _d);
              }
          
              function arr(address _a, uint256 _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
          
              function arr(address _a, address _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), _c, _d, _e);
              }
          
              function arr(address _a, address _b, address _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), uint256(_c));
              }
          
              function arr(address _a, address _b, uint256 _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), uint256(_c));
              }
          
              function arr(uint256 _a) internal pure returns (uint256[] r) {
                  r = new uint256[](1);
                  r[0] = _a;
              }
          
              function arr(uint256 _a, uint256 _b) internal pure returns (uint256[] r) {
                  r = new uint256[](2);
                  r[0] = _a;
                  r[1] = _b;
              }
          
              function arr(uint256 _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
                  r = new uint256[](3);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
              }
          
              function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
                  r = new uint256[](4);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
                  r[3] = _d;
              }
          
              function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
                  r = new uint256[](5);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
                  r[3] = _d;
                  r[4] = _e;
              }
          }
          
          
          contract ACLHelpers {
              function decodeParamOp(uint256 _x) internal pure returns (uint8 b) {
                  return uint8(_x >> (8 * 30));
              }
          
              function decodeParamId(uint256 _x) internal pure returns (uint8 b) {
                  return uint8(_x >> (8 * 31));
              }
          
              function decodeParamsList(uint256 _x) internal pure returns (uint32 a, uint32 b, uint32 c) {
                  a = uint32(_x);
                  b = uint32(_x >> (8 * 4));
                  c = uint32(_x >> (8 * 8));
              }
          }
          
          // File: contracts/common/ConversionHelpers.sol
          
          pragma solidity ^0.4.24;
          
          
          library ConversionHelpers {
              string private constant ERROR_IMPROPER_LENGTH = "CONVERSION_IMPROPER_LENGTH";
          
              function dangerouslyCastUintArrayToBytes(uint256[] memory _input) internal pure returns (bytes memory output) {
                  // Force cast the uint256[] into a bytes array, by overwriting its length
                  // Note that the bytes array doesn't need to be initialized as we immediately overwrite it
                  // with the input and a new length. The input becomes invalid from this point forward.
                  uint256 byteLength = _input.length * 32;
                  assembly {
                      output := _input
                      mstore(output, byteLength)
                  }
              }
          
              function dangerouslyCastBytesToUintArray(bytes memory _input) internal pure returns (uint256[] memory output) {
                  // Force cast the bytes array into a uint256[], by overwriting its length
                  // Note that the uint256[] doesn't need to be initialized as we immediately overwrite it
                  // with the input and a new length. The input becomes invalid from this point forward.
                  uint256 intsLength = _input.length / 32;
                  require(_input.length == intsLength * 32, ERROR_IMPROPER_LENGTH);
          
                  assembly {
                      output := _input
                      mstore(output, intsLength)
                  }
              }
          }
          
          // File: contracts/common/IsContract.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract IsContract {
              /*
              * NOTE: this should NEVER be used for authentication
              * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
              *
              * This is only intended to be used as a sanity check that an address is actually a contract,
              * RATHER THAN an address not being a contract.
              */
              function isContract(address _target) internal view returns (bool) {
                  if (_target == address(0)) {
                      return false;
                  }
          
                  uint256 size;
                  assembly { size := extcodesize(_target) }
                  return size > 0;
              }
          }
          
          // File: contracts/common/Uint256Helpers.sol
          
          pragma solidity ^0.4.24;
          
          
          library Uint256Helpers {
              uint256 private constant MAX_UINT64 = uint64(-1);
          
              string private constant ERROR_NUMBER_TOO_BIG = "UINT64_NUMBER_TOO_BIG";
          
              function toUint64(uint256 a) internal pure returns (uint64) {
                  require(a <= MAX_UINT64, ERROR_NUMBER_TOO_BIG);
                  return uint64(a);
              }
          }
          
          // File: contracts/common/TimeHelpers.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract TimeHelpers {
              using Uint256Helpers for uint256;
          
              /**
              * @dev Returns the current block number.
              *      Using a function rather than `block.number` allows us to easily mock the block number in
              *      tests.
              */
              function getBlockNumber() internal view returns (uint256) {
                  return block.number;
              }
          
              /**
              * @dev Returns the current block number, converted to uint64.
              *      Using a function rather than `block.number` allows us to easily mock the block number in
              *      tests.
              */
              function getBlockNumber64() internal view returns (uint64) {
                  return getBlockNumber().toUint64();
              }
          
              /**
              * @dev Returns the current timestamp.
              *      Using a function rather than `block.timestamp` allows us to easily mock it in
              *      tests.
              */
              function getTimestamp() internal view returns (uint256) {
                  return block.timestamp; // solium-disable-line security/no-block-members
              }
          
              /**
              * @dev Returns the current timestamp, converted to uint64.
              *      Using a function rather than `block.timestamp` allows us to easily mock it in
              *      tests.
              */
              function getTimestamp64() internal view returns (uint64) {
                  return getTimestamp().toUint64();
              }
          }
          
          // File: contracts/common/UnstructuredStorage.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          library UnstructuredStorage {
              function getStorageBool(bytes32 position) internal view returns (bool data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageAddress(bytes32 position) internal view returns (address data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
                  assembly { data := sload(position) }
              }
          
              function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
                  assembly { data := sload(position) }
              }
          
              function setStorageBool(bytes32 position, bool data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageAddress(bytes32 position, address data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageBytes32(bytes32 position, bytes32 data) internal {
                  assembly { sstore(position, data) }
              }
          
              function setStorageUint256(bytes32 position, uint256 data) internal {
                  assembly { sstore(position, data) }
              }
          }
          
          // File: contracts/common/Initializable.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          contract Initializable is TimeHelpers {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.initializable.initializationBlock")
              bytes32 internal constant INITIALIZATION_BLOCK_POSITION = 0xebb05b386a8d34882b8711d156f463690983dc47815980fb82aeeff1aa43579e;
          
              string private constant ERROR_ALREADY_INITIALIZED = "INIT_ALREADY_INITIALIZED";
              string private constant ERROR_NOT_INITIALIZED = "INIT_NOT_INITIALIZED";
          
              modifier onlyInit {
                  require(getInitializationBlock() == 0, ERROR_ALREADY_INITIALIZED);
                  _;
              }
          
              modifier isInitialized {
                  require(hasInitialized(), ERROR_NOT_INITIALIZED);
                  _;
              }
          
              /**
              * @return Block number in which the contract was initialized
              */
              function getInitializationBlock() public view returns (uint256) {
                  return INITIALIZATION_BLOCK_POSITION.getStorageUint256();
              }
          
              /**
              * @return Whether the contract has been initialized by the time of the current block
              */
              function hasInitialized() public view returns (bool) {
                  uint256 initializationBlock = getInitializationBlock();
                  return initializationBlock != 0 && getBlockNumber() >= initializationBlock;
              }
          
              /**
              * @dev Function to be called by top level contract after initialization has finished.
              */
              function initialized() internal onlyInit {
                  INITIALIZATION_BLOCK_POSITION.setStorageUint256(getBlockNumber());
              }
          
              /**
              * @dev Function to be called by top level contract after initialization to enable the contract
              *      at a future block number rather than immediately.
              */
              function initializedAt(uint256 _blockNumber) internal onlyInit {
                  INITIALIZATION_BLOCK_POSITION.setStorageUint256(_blockNumber);
              }
          }
          
          // File: contracts/common/Petrifiable.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          contract Petrifiable is Initializable {
              // Use block UINT256_MAX (which should be never) as the initializable date
              uint256 internal constant PETRIFIED_BLOCK = uint256(-1);
          
              function isPetrified() public view returns (bool) {
                  return getInitializationBlock() == PETRIFIED_BLOCK;
              }
          
              /**
              * @dev Function to be called by top level contract to prevent being initialized.
              *      Useful for freezing base contracts when they're used behind proxies.
              */
              function petrify() internal onlyInit {
                  initializedAt(PETRIFIED_BLOCK);
              }
          }
          
          // File: contracts/lib/token/ERC20.sol
          
          // See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/a9f910d34f0ab33a1ae5e714f69f9596a02b4d91/contracts/token/ERC20/ERC20.sol
          
          pragma solidity ^0.4.24;
          
          
          /**
           * @title ERC20 interface
           * @dev see https://github.com/ethereum/EIPs/issues/20
           */
          contract ERC20 {
              function totalSupply() public view returns (uint256);
          
              function balanceOf(address _who) public view returns (uint256);
          
              function allowance(address _owner, address _spender)
                  public view returns (uint256);
          
              function transfer(address _to, uint256 _value) public returns (bool);
          
              function approve(address _spender, uint256 _value)
                  public returns (bool);
          
              function transferFrom(address _from, address _to, uint256 _value)
                  public returns (bool);
          
              event Transfer(
                  address indexed from,
                  address indexed to,
                  uint256 value
              );
          
              event Approval(
                  address indexed owner,
                  address indexed spender,
                  uint256 value
              );
          }
          
          // File: contracts/common/EtherTokenConstant.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          // aragonOS and aragon-apps rely on address(0) to denote native ETH, in
          // contracts where both tokens and ETH are accepted
          contract EtherTokenConstant {
              address internal constant ETH = address(0);
          }
          
          // File: contracts/common/SafeERC20.sol
          
          // Inspired by AdEx (https://github.com/AdExNetwork/adex-protocol-eth/blob/b9df617829661a7518ee10f4cb6c4108659dd6d5/contracts/libs/SafeERC20.sol)
          // and 0x (https://github.com/0xProject/0x-monorepo/blob/737d1dc54d72872e24abce5a1dbe1b66d35fa21a/contracts/protocol/contracts/protocol/AssetProxy/ERC20Proxy.sol#L143)
          
          pragma solidity ^0.4.24;
          
          
          
          library SafeERC20 {
              // Before 0.5, solidity has a mismatch between `address.transfer()` and `token.transfer()`:
              // https://github.com/ethereum/solidity/issues/3544
              bytes4 private constant TRANSFER_SELECTOR = 0xa9059cbb;
          
              string private constant ERROR_TOKEN_BALANCE_REVERTED = "SAFE_ERC_20_BALANCE_REVERTED";
              string private constant ERROR_TOKEN_ALLOWANCE_REVERTED = "SAFE_ERC_20_ALLOWANCE_REVERTED";
          
              function invokeAndCheckSuccess(address _addr, bytes memory _calldata)
                  private
                  returns (bool)
              {
                  bool ret;
                  assembly {
                      let ptr := mload(0x40)    // free memory pointer
          
                      let success := call(
                          gas,                  // forward all gas
                          _addr,                // address
                          0,                    // no value
                          add(_calldata, 0x20), // calldata start
                          mload(_calldata),     // calldata length
                          ptr,                  // write output over free memory
                          0x20                  // uint256 return
                      )
          
                      if gt(success, 0) {
                          // Check number of bytes returned from last function call
                          switch returndatasize
          
                          // No bytes returned: assume success
                          case 0 {
                              ret := 1
                          }
          
                          // 32 bytes returned: check if non-zero
                          case 0x20 {
                              // Only return success if returned data was true
                              // Already have output in ptr
                              ret := eq(mload(ptr), 1)
                          }
          
                          // Not sure what was returned: don't mark as success
                          default { }
                      }
                  }
                  return ret;
              }
          
              function staticInvoke(address _addr, bytes memory _calldata)
                  private
                  view
                  returns (bool, uint256)
              {
                  bool success;
                  uint256 ret;
                  assembly {
                      let ptr := mload(0x40)    // free memory pointer
          
                      success := staticcall(
                          gas,                  // forward all gas
                          _addr,                // address
                          add(_calldata, 0x20), // calldata start
                          mload(_calldata),     // calldata length
                          ptr,                  // write output over free memory
                          0x20                  // uint256 return
                      )
          
                      if gt(success, 0) {
                          ret := mload(ptr)
                      }
                  }
                  return (success, ret);
              }
          
              /**
              * @dev Same as a standards-compliant ERC20.transfer() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeTransfer(ERC20 _token, address _to, uint256 _amount) internal returns (bool) {
                  bytes memory transferCallData = abi.encodeWithSelector(
                      TRANSFER_SELECTOR,
                      _to,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, transferCallData);
              }
          
              /**
              * @dev Same as a standards-compliant ERC20.transferFrom() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeTransferFrom(ERC20 _token, address _from, address _to, uint256 _amount) internal returns (bool) {
                  bytes memory transferFromCallData = abi.encodeWithSelector(
                      _token.transferFrom.selector,
                      _from,
                      _to,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, transferFromCallData);
              }
          
              /**
              * @dev Same as a standards-compliant ERC20.approve() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeApprove(ERC20 _token, address _spender, uint256 _amount) internal returns (bool) {
                  bytes memory approveCallData = abi.encodeWithSelector(
                      _token.approve.selector,
                      _spender,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, approveCallData);
              }
          
              /**
              * @dev Static call into ERC20.balanceOf().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticBalanceOf(ERC20 _token, address _owner) internal view returns (uint256) {
                  bytes memory balanceOfCallData = abi.encodeWithSelector(
                      _token.balanceOf.selector,
                      _owner
                  );
          
                  (bool success, uint256 tokenBalance) = staticInvoke(_token, balanceOfCallData);
                  require(success, ERROR_TOKEN_BALANCE_REVERTED);
          
                  return tokenBalance;
              }
          
              /**
              * @dev Static call into ERC20.allowance().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticAllowance(ERC20 _token, address _owner, address _spender) internal view returns (uint256) {
                  bytes memory allowanceCallData = abi.encodeWithSelector(
                      _token.allowance.selector,
                      _owner,
                      _spender
                  );
          
                  (bool success, uint256 allowance) = staticInvoke(_token, allowanceCallData);
                  require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);
          
                  return allowance;
              }
          
              /**
              * @dev Static call into ERC20.totalSupply().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticTotalSupply(ERC20 _token) internal view returns (uint256) {
                  bytes memory totalSupplyCallData = abi.encodeWithSelector(_token.totalSupply.selector);
          
                  (bool success, uint256 totalSupply) = staticInvoke(_token, totalSupplyCallData);
                  require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);
          
                  return totalSupply;
              }
          }
          
          // File: contracts/common/VaultRecoverable.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          
          
          
          contract VaultRecoverable is IVaultRecoverable, EtherTokenConstant, IsContract {
              using SafeERC20 for ERC20;
          
              string private constant ERROR_DISALLOWED = "RECOVER_DISALLOWED";
              string private constant ERROR_VAULT_NOT_CONTRACT = "RECOVER_VAULT_NOT_CONTRACT";
              string private constant ERROR_TOKEN_TRANSFER_FAILED = "RECOVER_TOKEN_TRANSFER_FAILED";
          
              /**
               * @notice Send funds to recovery Vault. This contract should never receive funds,
               *         but in case it does, this function allows one to recover them.
               * @param _token Token balance to be sent to recovery vault.
               */
              function transferToVault(address _token) external {
                  require(allowRecoverability(_token), ERROR_DISALLOWED);
                  address vault = getRecoveryVault();
                  require(isContract(vault), ERROR_VAULT_NOT_CONTRACT);
          
                  uint256 balance;
                  if (_token == ETH) {
                      balance = address(this).balance;
                      vault.transfer(balance);
                  } else {
                      ERC20 token = ERC20(_token);
                      balance = token.staticBalanceOf(this);
                      require(token.safeTransfer(vault, balance), ERROR_TOKEN_TRANSFER_FAILED);
                  }
          
                  emit RecoverToVault(vault, _token, balance);
              }
          
              /**
              * @dev By default deriving from AragonApp makes it recoverable
              * @param token Token address that would be recovered
              * @return bool whether the app allows the recovery
              */
              function allowRecoverability(address token) public view returns (bool) {
                  return true;
              }
          
              // Cast non-implemented interface to be public so we can use it internally
              function getRecoveryVault() public view returns (address);
          }
          
          // File: contracts/apps/AppStorage.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          
          
          contract AppStorage {
              using UnstructuredStorage for bytes32;
          
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
              bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
              */
              bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
              bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;
          
              function kernel() public view returns (IKernel) {
                  return IKernel(KERNEL_POSITION.getStorageAddress());
              }
          
              function appId() public view returns (bytes32) {
                  return APP_ID_POSITION.getStorageBytes32();
              }
          
              function setKernel(IKernel _kernel) internal {
                  KERNEL_POSITION.setStorageAddress(address(_kernel));
              }
          
              function setAppId(bytes32 _appId) internal {
                  APP_ID_POSITION.setStorageBytes32(_appId);
              }
          }
          
          // File: contracts/lib/misc/ERCProxy.sol
          
          /*
           * SPDX-License-Identitifer:    MIT
           */
          
          pragma solidity ^0.4.24;
          
          
          contract ERCProxy {
              uint256 internal constant FORWARDING = 1;
              uint256 internal constant UPGRADEABLE = 2;
          
              function proxyType() public pure returns (uint256 proxyTypeId);
              function implementation() public view returns (address codeAddr);
          }
          
          // File: contracts/common/DelegateProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract DelegateProxy is ERCProxy, IsContract {
              uint256 internal constant FWD_GAS_LIMIT = 10000;
          
              /**
              * @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
              * @param _dst Destination address to perform the delegatecall
              * @param _calldata Calldata for the delegatecall
              */
              function delegatedFwd(address _dst, bytes _calldata) internal {
                  require(isContract(_dst));
                  uint256 fwdGasLimit = FWD_GAS_LIMIT;
          
                  assembly {
                      let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
                      let size := returndatasize
                      let ptr := mload(0x40)
                      returndatacopy(ptr, 0, size)
          
                      // revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
                      // if the call returned error data, forward it
                      switch result case 0 { revert(ptr, size) }
                      default { return(ptr, size) }
                  }
              }
          }
          
          // File: contracts/common/DepositableStorage.sol
          
          pragma solidity 0.4.24;
          
          
          
          contract DepositableStorage {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.depositableStorage.depositable")
              bytes32 internal constant DEPOSITABLE_POSITION = 0x665fd576fbbe6f247aff98f5c94a561e3f71ec2d3c988d56f12d342396c50cea;
          
              function isDepositable() public view returns (bool) {
                  return DEPOSITABLE_POSITION.getStorageBool();
              }
          
              function setDepositable(bool _depositable) internal {
                  DEPOSITABLE_POSITION.setStorageBool(_depositable);
              }
          }
          
          // File: contracts/common/DepositableDelegateProxy.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract DepositableDelegateProxy is DepositableStorage, DelegateProxy {
              event ProxyDeposit(address sender, uint256 value);
          
              function () external payable {
                  uint256 forwardGasThreshold = FWD_GAS_LIMIT;
                  bytes32 isDepositablePosition = DEPOSITABLE_POSITION;
          
                  // Optimized assembly implementation to prevent EIP-1884 from breaking deposits, reference code in Solidity:
                  // https://github.com/aragon/aragonOS/blob/v4.2.1/contracts/common/DepositableDelegateProxy.sol#L10-L20
                  assembly {
                      // Continue only if the gas left is lower than the threshold for forwarding to the implementation code,
                      // otherwise continue outside of the assembly block.
                      if lt(gas, forwardGasThreshold) {
                          // Only accept the deposit and emit an event if all of the following are true:
                          // the proxy accepts deposits (isDepositable), msg.data.length == 0, and msg.value > 0
                          if and(and(sload(isDepositablePosition), iszero(calldatasize)), gt(callvalue, 0)) {
                              // Equivalent Solidity code for emitting the event:
                              // emit ProxyDeposit(msg.sender, msg.value);
          
                              let logData := mload(0x40) // free memory pointer
                              mstore(logData, caller) // add 'msg.sender' to the log data (first event param)
                              mstore(add(logData, 0x20), callvalue) // add 'msg.value' to the log data (second event param)
          
                              // Emit an event with one topic to identify the event: keccak256('ProxyDeposit(address,uint256)') = 0x15ee...dee1
                              log1(logData, 0x40, 0x15eeaa57c7bd188c1388020bcadc2c436ec60d647d36ef5b9eb3c742217ddee1)
          
                              stop() // Stop. Exits execution context
                          }
          
                          // If any of above checks failed, revert the execution (if ETH was sent, it is returned to the sender)
                          revert(0, 0)
                      }
                  }
          
                  address target = implementation();
                  delegatedFwd(target, msg.data);
              }
          }
          
          // File: contracts/apps/AppProxyBase.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          contract AppProxyBase is AppStorage, DepositableDelegateProxy, KernelNamespaceConstants {
              /**
              * @dev Initialize AppProxy
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public {
                  setKernel(_kernel);
                  setAppId(_appId);
          
                  // Implicit check that kernel is actually a Kernel
                  // The EVM doesn't actually provide a way for us to make sure, but we can force a revert to
                  // occur if the kernel is set to 0x0 or a non-code address when we try to call a method on
                  // it.
                  address appCode = getAppBase(_appId);
          
                  // If initialize payload is provided, it will be executed
                  if (_initializePayload.length > 0) {
                      require(isContract(appCode));
                      // Cannot make delegatecall as a delegateproxy.delegatedFwd as it
                      // returns ending execution context and halts contract deployment
                      require(appCode.delegatecall(_initializePayload));
                  }
              }
          
              function getAppBase(bytes32 _appId) internal view returns (address) {
                  return kernel().getApp(KERNEL_APP_BASES_NAMESPACE, _appId);
              }
          }
          
          // File: contracts/apps/AppProxyUpgradeable.sol
          
          pragma solidity 0.4.24;
          
          
          
          contract AppProxyUpgradeable is AppProxyBase {
              /**
              * @dev Initialize AppProxyUpgradeable (makes it an upgradeable Aragon app)
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
                  AppProxyBase(_kernel, _appId, _initializePayload)
                  public // solium-disable-line visibility-first
              {
                  // solium-disable-previous-line no-empty-blocks
              }
          
              /**
               * @dev ERC897, the address the proxy would delegate calls to
               */
              function implementation() public view returns (address) {
                  return getAppBase(appId());
              }
          
              /**
               * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
               */
              function proxyType() public pure returns (uint256 proxyTypeId) {
                  return UPGRADEABLE;
              }
          }
          
          // File: contracts/apps/AppProxyPinned.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          contract AppProxyPinned is IsContract, AppProxyBase {
              using UnstructuredStorage for bytes32;
          
              // keccak256("aragonOS.appStorage.pinnedCode")
              bytes32 internal constant PINNED_CODE_POSITION = 0xdee64df20d65e53d7f51cb6ab6d921a0a6a638a91e942e1d8d02df28e31c038e;
          
              /**
              * @dev Initialize AppProxyPinned (makes it an un-upgradeable Aragon app)
              * @param _kernel Reference to organization kernel for the app
              * @param _appId Identifier for app
              * @param _initializePayload Payload for call to be made after setup to initialize
              */
              constructor(IKernel _kernel, bytes32 _appId, bytes _initializePayload)
                  AppProxyBase(_kernel, _appId, _initializePayload)
                  public // solium-disable-line visibility-first
              {
                  setPinnedCode(getAppBase(_appId));
                  require(isContract(pinnedCode()));
              }
          
              /**
               * @dev ERC897, the address the proxy would delegate calls to
               */
              function implementation() public view returns (address) {
                  return pinnedCode();
              }
          
              /**
               * @dev ERC897, whether it is a forwarding (1) or an upgradeable (2) proxy
               */
              function proxyType() public pure returns (uint256 proxyTypeId) {
                  return FORWARDING;
              }
          
              function setPinnedCode(address _pinnedCode) internal {
                  PINNED_CODE_POSITION.setStorageAddress(_pinnedCode);
              }
          
              function pinnedCode() internal view returns (address) {
                  return PINNED_CODE_POSITION.getStorageAddress();
              }
          }
          
          // File: contracts/factory/AppProxyFactory.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          contract AppProxyFactory {
              event NewAppProxy(address proxy, bool isUpgradeable, bytes32 appId);
          
              /**
              * @notice Create a new upgradeable app instance on `_kernel` with identifier `_appId`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @return AppProxyUpgradeable
              */
              function newAppProxy(IKernel _kernel, bytes32 _appId) public returns (AppProxyUpgradeable) {
                  return newAppProxy(_kernel, _appId, new bytes(0));
              }
          
              /**
              * @notice Create a new upgradeable app instance on `_kernel` with identifier `_appId` and initialization payload `_initializePayload`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @return AppProxyUpgradeable
              */
              function newAppProxy(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public returns (AppProxyUpgradeable) {
                  AppProxyUpgradeable proxy = new AppProxyUpgradeable(_kernel, _appId, _initializePayload);
                  emit NewAppProxy(address(proxy), true, _appId);
                  return proxy;
              }
          
              /**
              * @notice Create a new pinned app instance on `_kernel` with identifier `_appId`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @return AppProxyPinned
              */
              function newAppProxyPinned(IKernel _kernel, bytes32 _appId) public returns (AppProxyPinned) {
                  return newAppProxyPinned(_kernel, _appId, new bytes(0));
              }
          
              /**
              * @notice Create a new pinned app instance on `_kernel` with identifier `_appId` and initialization payload `_initializePayload`
              * @param _kernel App's Kernel reference
              * @param _appId Identifier for app
              * @param _initializePayload Proxy initialization payload
              * @return AppProxyPinned
              */
              function newAppProxyPinned(IKernel _kernel, bytes32 _appId, bytes _initializePayload) public returns (AppProxyPinned) {
                  AppProxyPinned proxy = new AppProxyPinned(_kernel, _appId, _initializePayload);
                  emit NewAppProxy(address(proxy), false, _appId);
                  return proxy;
              }
          }
          
          // File: contracts/kernel/Kernel.sol
          
          pragma solidity 0.4.24;
          
          
          
          
          
          
          
          
          
          
          
          
          
          // solium-disable-next-line max-len
          contract Kernel is IKernel, KernelStorage, KernelAppIds, KernelNamespaceConstants, Petrifiable, IsContract, VaultRecoverable, AppProxyFactory, ACLSyntaxSugar {
              /* Hardcoded constants to save gas
              bytes32 public constant APP_MANAGER_ROLE = keccak256("APP_MANAGER_ROLE");
              */
              bytes32 public constant APP_MANAGER_ROLE = 0xb6d92708f3d4817afc106147d969e229ced5c46e65e0a5002a0d391287762bd0;
          
              string private constant ERROR_APP_NOT_CONTRACT = "KERNEL_APP_NOT_CONTRACT";
              string private constant ERROR_INVALID_APP_CHANGE = "KERNEL_INVALID_APP_CHANGE";
              string private constant ERROR_AUTH_FAILED = "KERNEL_AUTH_FAILED";
          
              /**
              * @dev Constructor that allows the deployer to choose if the base instance should be petrified immediately.
              * @param _shouldPetrify Immediately petrify this instance so that it can never be initialized
              */
              constructor(bool _shouldPetrify) public {
                  if (_shouldPetrify) {
                      petrify();
                  }
              }
          
              /**
              * @dev Initialize can only be called once. It saves the block number in which it was initialized.
              * @notice Initialize this kernel instance along with its ACL and set `_permissionsCreator` as the entity that can create other permissions
              * @param _baseAcl Address of base ACL app
              * @param _permissionsCreator Entity that will be given permission over createPermission
              */
              function initialize(IACL _baseAcl, address _permissionsCreator) public onlyInit {
                  initialized();
          
                  // Set ACL base
                  _setApp(KERNEL_APP_BASES_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID, _baseAcl);
          
                  // Create ACL instance and attach it as the default ACL app
                  IACL acl = IACL(newAppProxy(this, KERNEL_DEFAULT_ACL_APP_ID));
                  acl.initialize(_permissionsCreator);
                  _setApp(KERNEL_APP_ADDR_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID, acl);
          
                  recoveryVaultAppId = KERNEL_DEFAULT_VAULT_APP_ID;
              }
          
              /**
              * @dev Create a new instance of an app linked to this kernel
              * @notice Create a new upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @return AppProxy instance
              */
              function newAppInstance(bytes32 _appId, address _appBase)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  return newAppInstance(_appId, _appBase, new bytes(0), false);
              }
          
              /**
              * @dev Create a new instance of an app linked to this kernel and set its base
              *      implementation if it was not already set
              * @notice Create a new upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`. `_setDefault ? 'Also sets it as the default app instance.':''`
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @param _initializePayload Payload for call made by the proxy during its construction to initialize
              * @param _setDefault Whether the app proxy app is the default one.
              *        Useful when the Kernel needs to know of an instance of a particular app,
              *        like Vault for escape hatch mechanism.
              * @return AppProxy instance
              */
              function newAppInstance(bytes32 _appId, address _appBase, bytes _initializePayload, bool _setDefault)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  _setAppIfNew(KERNEL_APP_BASES_NAMESPACE, _appId, _appBase);
                  appProxy = newAppProxy(this, _appId, _initializePayload);
                  // By calling setApp directly and not the internal functions, we make sure the params are checked
                  // and it will only succeed if sender has permissions to set something to the namespace.
                  if (_setDefault) {
                      setApp(KERNEL_APP_ADDR_NAMESPACE, _appId, appProxy);
                  }
              }
          
              /**
              * @dev Create a new pinned instance of an app linked to this kernel
              * @notice Create a new non-upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`.
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @return AppProxy instance
              */
              function newPinnedAppInstance(bytes32 _appId, address _appBase)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  return newPinnedAppInstance(_appId, _appBase, new bytes(0), false);
              }
          
              /**
              * @dev Create a new pinned instance of an app linked to this kernel and set
              *      its base implementation if it was not already set
              * @notice Create a new non-upgradeable instance of `_appId` app linked to the Kernel, setting its code to `_appBase`. `_setDefault ? 'Also sets it as the default app instance.':''`
              * @param _appId Identifier for app
              * @param _appBase Address of the app's base implementation
              * @param _initializePayload Payload for call made by the proxy during its construction to initialize
              * @param _setDefault Whether the app proxy app is the default one.
              *        Useful when the Kernel needs to know of an instance of a particular app,
              *        like Vault for escape hatch mechanism.
              * @return AppProxy instance
              */
              function newPinnedAppInstance(bytes32 _appId, address _appBase, bytes _initializePayload, bool _setDefault)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_BASES_NAMESPACE, _appId))
                  returns (ERCProxy appProxy)
              {
                  _setAppIfNew(KERNEL_APP_BASES_NAMESPACE, _appId, _appBase);
                  appProxy = newAppProxyPinned(this, _appId, _initializePayload);
                  // By calling setApp directly and not the internal functions, we make sure the params are checked
                  // and it will only succeed if sender has permissions to set something to the namespace.
                  if (_setDefault) {
                      setApp(KERNEL_APP_ADDR_NAMESPACE, _appId, appProxy);
                  }
              }
          
              /**
              * @dev Set the resolving address of an app instance or base implementation
              * @notice Set the resolving address of `_appId` in namespace `_namespace` to `_app`
              * @param _namespace App namespace to use
              * @param _appId Identifier for app
              * @param _app Address of the app instance or base implementation
              * @return ID of app
              */
              function setApp(bytes32 _namespace, bytes32 _appId, address _app)
                  public
                  auth(APP_MANAGER_ROLE, arr(_namespace, _appId))
              {
                  _setApp(_namespace, _appId, _app);
              }
          
              /**
              * @dev Set the default vault id for the escape hatch mechanism
              * @param _recoveryVaultAppId Identifier of the recovery vault app
              */
              function setRecoveryVaultAppId(bytes32 _recoveryVaultAppId)
                  public
                  auth(APP_MANAGER_ROLE, arr(KERNEL_APP_ADDR_NAMESPACE, _recoveryVaultAppId))
              {
                  recoveryVaultAppId = _recoveryVaultAppId;
              }
          
              // External access to default app id and namespace constants to mimic default getters for constants
              /* solium-disable function-order, mixedcase */
              function CORE_NAMESPACE() external pure returns (bytes32) { return KERNEL_CORE_NAMESPACE; }
              function APP_BASES_NAMESPACE() external pure returns (bytes32) { return KERNEL_APP_BASES_NAMESPACE; }
              function APP_ADDR_NAMESPACE() external pure returns (bytes32) { return KERNEL_APP_ADDR_NAMESPACE; }
              function KERNEL_APP_ID() external pure returns (bytes32) { return KERNEL_CORE_APP_ID; }
              function DEFAULT_ACL_APP_ID() external pure returns (bytes32) { return KERNEL_DEFAULT_ACL_APP_ID; }
              /* solium-enable function-order, mixedcase */
          
              /**
              * @dev Get the address of an app instance or base implementation
              * @param _namespace App namespace to use
              * @param _appId Identifier for app
              * @return Address of the app
              */
              function getApp(bytes32 _namespace, bytes32 _appId) public view returns (address) {
                  return apps[_namespace][_appId];
              }
          
              /**
              * @dev Get the address of the recovery Vault instance (to recover funds)
              * @return Address of the Vault
              */
              function getRecoveryVault() public view returns (address) {
                  return apps[KERNEL_APP_ADDR_NAMESPACE][recoveryVaultAppId];
              }
          
              /**
              * @dev Get the installed ACL app
              * @return ACL app
              */
              function acl() public view returns (IACL) {
                  return IACL(getApp(KERNEL_APP_ADDR_NAMESPACE, KERNEL_DEFAULT_ACL_APP_ID));
              }
          
              /**
              * @dev Function called by apps to check ACL on kernel or to check permission status
              * @param _who Sender of the original call
              * @param _where Address of the app
              * @param _what Identifier for a group of actions in app
              * @param _how Extra data for ACL auth
              * @return Boolean indicating whether the ACL allows the role or not.
              *         Always returns false if the kernel hasn't been initialized yet.
              */
              function hasPermission(address _who, address _where, bytes32 _what, bytes _how) public view returns (bool) {
                  IACL defaultAcl = acl();
                  return address(defaultAcl) != address(0) && // Poor man's initialization check (saves gas)
                      defaultAcl.hasPermission(_who, _where, _what, _how);
              }
          
              function _setApp(bytes32 _namespace, bytes32 _appId, address _app) internal {
                  require(isContract(_app), ERROR_APP_NOT_CONTRACT);
                  apps[_namespace][_appId] = _app;
                  emit SetApp(_namespace, _appId, _app);
              }
          
              function _setAppIfNew(bytes32 _namespace, bytes32 _appId, address _app) internal {
                  address app = getApp(_namespace, _appId);
                  if (app != address(0)) {
                      // The only way to set an app is if it passes the isContract check, so no need to check it again
                      require(app == _app, ERROR_INVALID_APP_CHANGE);
                  } else {
                      _setApp(_namespace, _appId, _app);
                  }
              }
          
              modifier auth(bytes32 _role, uint256[] memory _params) {
                  require(
                      hasPermission(msg.sender, address(this), _role, ConversionHelpers.dangerouslyCastUintArrayToBytes(_params)),
                      ERROR_AUTH_FAILED
                  );
                  _;
              }
          }

          File 6 of 6: Lido
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          contract ACLSyntaxSugar {
              function arr() internal pure returns (uint256[]) {
                  return new uint256[](0);
              }
              function arr(bytes32 _a) internal pure returns (uint256[] r) {
                  return arr(uint256(_a));
              }
              function arr(bytes32 _a, bytes32 _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
              function arr(address _a) internal pure returns (uint256[] r) {
                  return arr(uint256(_a));
              }
              function arr(address _a, address _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
              function arr(address _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), _b, _c);
              }
              function arr(address _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), _b, _c, _d);
              }
              function arr(address _a, uint256 _b) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b));
              }
              function arr(address _a, address _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), _c, _d, _e);
              }
              function arr(address _a, address _b, address _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), uint256(_c));
              }
              function arr(address _a, address _b, uint256 _c) internal pure returns (uint256[] r) {
                  return arr(uint256(_a), uint256(_b), uint256(_c));
              }
              function arr(uint256 _a) internal pure returns (uint256[] r) {
                  r = new uint256[](1);
                  r[0] = _a;
              }
              function arr(uint256 _a, uint256 _b) internal pure returns (uint256[] r) {
                  r = new uint256[](2);
                  r[0] = _a;
                  r[1] = _b;
              }
              function arr(uint256 _a, uint256 _b, uint256 _c) internal pure returns (uint256[] r) {
                  r = new uint256[](3);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
              }
              function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d) internal pure returns (uint256[] r) {
                  r = new uint256[](4);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
                  r[3] = _d;
              }
              function arr(uint256 _a, uint256 _b, uint256 _c, uint256 _d, uint256 _e) internal pure returns (uint256[] r) {
                  r = new uint256[](5);
                  r[0] = _a;
                  r[1] = _b;
                  r[2] = _c;
                  r[3] = _d;
                  r[4] = _e;
              }
          }
          contract ACLHelpers {
              function decodeParamOp(uint256 _x) internal pure returns (uint8 b) {
                  return uint8(_x >> (8 * 30));
              }
              function decodeParamId(uint256 _x) internal pure returns (uint8 b) {
                  return uint8(_x >> (8 * 31));
              }
              function decodeParamsList(uint256 _x) internal pure returns (uint32 a, uint32 b, uint32 c) {
                  a = uint32(_x);
                  b = uint32(_x >> (8 * 4));
                  c = uint32(_x >> (8 * 8));
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          interface IACL {
              function initialize(address permissionsCreator) external;
              // TODO: this should be external
              // See https://github.com/ethereum/solidity/issues/4832
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "../common/UnstructuredStorage.sol";
          import "../kernel/IKernel.sol";
          contract AppStorage {
              using UnstructuredStorage for bytes32;
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_POSITION = keccak256("aragonOS.appStorage.kernel");
              bytes32 internal constant APP_ID_POSITION = keccak256("aragonOS.appStorage.appId");
              */
              bytes32 internal constant KERNEL_POSITION = 0x4172f0f7d2289153072b0a6ca36959e0cbe2efc3afe50fc81636caa96338137b;
              bytes32 internal constant APP_ID_POSITION = 0xd625496217aa6a3453eecb9c3489dc5a53e6c67b444329ea2b2cbc9ff547639b;
              function kernel() public view returns (IKernel) {
                  return IKernel(KERNEL_POSITION.getStorageAddress());
              }
              function appId() public view returns (bytes32) {
                  return APP_ID_POSITION.getStorageBytes32();
              }
              function setKernel(IKernel _kernel) internal {
                  KERNEL_POSITION.setStorageAddress(address(_kernel));
              }
              function setAppId(bytes32 _appId) internal {
                  APP_ID_POSITION.setStorageBytes32(_appId);
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./AppStorage.sol";
          import "../acl/ACLSyntaxSugar.sol";
          import "../common/Autopetrified.sol";
          import "../common/ConversionHelpers.sol";
          import "../common/ReentrancyGuard.sol";
          import "../common/VaultRecoverable.sol";
          import "../evmscript/EVMScriptRunner.sol";
          // Contracts inheriting from AragonApp are, by default, immediately petrified upon deployment so
          // that they can never be initialized.
          // Unless overriden, this behaviour enforces those contracts to be usable only behind an AppProxy.
          // ReentrancyGuard, EVMScriptRunner, and ACLSyntaxSugar are not directly used by this contract, but
          // are included so that they are automatically usable by subclassing contracts
          contract AragonApp is AppStorage, Autopetrified, VaultRecoverable, ReentrancyGuard, EVMScriptRunner, ACLSyntaxSugar {
              string private constant ERROR_AUTH_FAILED = "APP_AUTH_FAILED";
              modifier auth(bytes32 _role) {
                  require(canPerform(msg.sender, _role, new uint256[](0)), ERROR_AUTH_FAILED);
                  _;
              }
              modifier authP(bytes32 _role, uint256[] _params) {
                  require(canPerform(msg.sender, _role, _params), ERROR_AUTH_FAILED);
                  _;
              }
              /**
              * @dev Check whether an action can be performed by a sender for a particular role on this app
              * @param _sender Sender of the call
              * @param _role Role on this app
              * @param _params Permission params for the role
              * @return Boolean indicating whether the sender has the permissions to perform the action.
              *         Always returns false if the app hasn't been initialized yet.
              */
              function canPerform(address _sender, bytes32 _role, uint256[] _params) public view returns (bool) {
                  if (!hasInitialized()) {
                      return false;
                  }
                  IKernel linkedKernel = kernel();
                  if (address(linkedKernel) == address(0)) {
                      return false;
                  }
                  return linkedKernel.hasPermission(
                      _sender,
                      address(this),
                      _role,
                      ConversionHelpers.dangerouslyCastUintArrayToBytes(_params)
                  );
              }
              /**
              * @dev Get the recovery vault for the app
              * @return Recovery vault address for the app
              */
              function getRecoveryVault() public view returns (address) {
                  // Funds recovery via a vault is only available when used with a kernel
                  return kernel().getRecoveryVault(); // if kernel is not set, it will revert
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./Petrifiable.sol";
          contract Autopetrified is Petrifiable {
              constructor() public {
                  // Immediately petrify base (non-proxy) instances of inherited contracts on deploy.
                  // This renders them uninitializable (and unusable without a proxy).
                  petrify();
              }
          }
          pragma solidity ^0.4.24;
          library ConversionHelpers {
              string private constant ERROR_IMPROPER_LENGTH = "CONVERSION_IMPROPER_LENGTH";
              function dangerouslyCastUintArrayToBytes(uint256[] memory _input) internal pure returns (bytes memory output) {
                  // Force cast the uint256[] into a bytes array, by overwriting its length
                  // Note that the bytes array doesn't need to be initialized as we immediately overwrite it
                  // with the input and a new length. The input becomes invalid from this point forward.
                  uint256 byteLength = _input.length * 32;
                  assembly {
                      output := _input
                      mstore(output, byteLength)
                  }
              }
              function dangerouslyCastBytesToUintArray(bytes memory _input) internal pure returns (uint256[] memory output) {
                  // Force cast the bytes array into a uint256[], by overwriting its length
                  // Note that the uint256[] doesn't need to be initialized as we immediately overwrite it
                  // with the input and a new length. The input becomes invalid from this point forward.
                  uint256 intsLength = _input.length / 32;
                  require(_input.length == intsLength * 32, ERROR_IMPROPER_LENGTH);
                  assembly {
                      output := _input
                      mstore(output, intsLength)
                  }
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          // aragonOS and aragon-apps rely on address(0) to denote native ETH, in
          // contracts where both tokens and ETH are accepted
          contract EtherTokenConstant {
              address internal constant ETH = address(0);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./TimeHelpers.sol";
          import "./UnstructuredStorage.sol";
          contract Initializable is TimeHelpers {
              using UnstructuredStorage for bytes32;
              // keccak256("aragonOS.initializable.initializationBlock")
              bytes32 internal constant INITIALIZATION_BLOCK_POSITION = 0xebb05b386a8d34882b8711d156f463690983dc47815980fb82aeeff1aa43579e;
              string private constant ERROR_ALREADY_INITIALIZED = "INIT_ALREADY_INITIALIZED";
              string private constant ERROR_NOT_INITIALIZED = "INIT_NOT_INITIALIZED";
              modifier onlyInit {
                  require(getInitializationBlock() == 0, ERROR_ALREADY_INITIALIZED);
                  _;
              }
              modifier isInitialized {
                  require(hasInitialized(), ERROR_NOT_INITIALIZED);
                  _;
              }
              /**
              * @return Block number in which the contract was initialized
              */
              function getInitializationBlock() public view returns (uint256) {
                  return INITIALIZATION_BLOCK_POSITION.getStorageUint256();
              }
              /**
              * @return Whether the contract has been initialized by the time of the current block
              */
              function hasInitialized() public view returns (bool) {
                  uint256 initializationBlock = getInitializationBlock();
                  return initializationBlock != 0 && getBlockNumber() >= initializationBlock;
              }
              /**
              * @dev Function to be called by top level contract after initialization has finished.
              */
              function initialized() internal onlyInit {
                  INITIALIZATION_BLOCK_POSITION.setStorageUint256(getBlockNumber());
              }
              /**
              * @dev Function to be called by top level contract after initialization to enable the contract
              *      at a future block number rather than immediately.
              */
              function initializedAt(uint256 _blockNumber) internal onlyInit {
                  INITIALIZATION_BLOCK_POSITION.setStorageUint256(_blockNumber);
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          contract IsContract {
              /*
              * NOTE: this should NEVER be used for authentication
              * (see pitfalls: https://github.com/fergarrui/ethereum-security/tree/master/contracts/extcodesize).
              *
              * This is only intended to be used as a sanity check that an address is actually a contract,
              * RATHER THAN an address not being a contract.
              */
              function isContract(address _target) internal view returns (bool) {
                  if (_target == address(0)) {
                      return false;
                  }
                  uint256 size;
                  assembly { size := extcodesize(_target) }
                  return size > 0;
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          interface IVaultRecoverable {
              event RecoverToVault(address indexed vault, address indexed token, uint256 amount);
              function transferToVault(address token) external;
              function allowRecoverability(address token) external view returns (bool);
              function getRecoveryVault() external view returns (address);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./Initializable.sol";
          contract Petrifiable is Initializable {
              // Use block UINT256_MAX (which should be never) as the initializable date
              uint256 internal constant PETRIFIED_BLOCK = uint256(-1);
              function isPetrified() public view returns (bool) {
                  return getInitializationBlock() == PETRIFIED_BLOCK;
              }
              /**
              * @dev Function to be called by top level contract to prevent being initialized.
              *      Useful for freezing base contracts when they're used behind proxies.
              */
              function petrify() internal onlyInit {
                  initializedAt(PETRIFIED_BLOCK);
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "../common/UnstructuredStorage.sol";
          contract ReentrancyGuard {
              using UnstructuredStorage for bytes32;
              /* Hardcoded constants to save gas
              bytes32 internal constant REENTRANCY_MUTEX_POSITION = keccak256("aragonOS.reentrancyGuard.mutex");
              */
              bytes32 private constant REENTRANCY_MUTEX_POSITION = 0xe855346402235fdd185c890e68d2c4ecad599b88587635ee285bce2fda58dacb;
              string private constant ERROR_REENTRANT = "REENTRANCY_REENTRANT_CALL";
              modifier nonReentrant() {
                  // Ensure mutex is unlocked
                  require(!REENTRANCY_MUTEX_POSITION.getStorageBool(), ERROR_REENTRANT);
                  // Lock mutex before function call
                  REENTRANCY_MUTEX_POSITION.setStorageBool(true);
                  // Perform function call
                  _;
                  // Unlock mutex after function call
                  REENTRANCY_MUTEX_POSITION.setStorageBool(false);
              }
          }
          // Inspired by AdEx (https://github.com/AdExNetwork/adex-protocol-eth/blob/b9df617829661a7518ee10f4cb6c4108659dd6d5/contracts/libs/SafeERC20.sol)
          // and 0x (https://github.com/0xProject/0x-monorepo/blob/737d1dc54d72872e24abce5a1dbe1b66d35fa21a/contracts/protocol/contracts/protocol/AssetProxy/ERC20Proxy.sol#L143)
          pragma solidity ^0.4.24;
          import "../lib/token/ERC20.sol";
          library SafeERC20 {
              // Before 0.5, solidity has a mismatch between `address.transfer()` and `token.transfer()`:
              // https://github.com/ethereum/solidity/issues/3544
              bytes4 private constant TRANSFER_SELECTOR = 0xa9059cbb;
              string private constant ERROR_TOKEN_BALANCE_REVERTED = "SAFE_ERC_20_BALANCE_REVERTED";
              string private constant ERROR_TOKEN_ALLOWANCE_REVERTED = "SAFE_ERC_20_ALLOWANCE_REVERTED";
              function invokeAndCheckSuccess(address _addr, bytes memory _calldata)
                  private
                  returns (bool)
              {
                  bool ret;
                  assembly {
                      let ptr := mload(0x40)    // free memory pointer
                      let success := call(
                          gas,                  // forward all gas
                          _addr,                // address
                          0,                    // no value
                          add(_calldata, 0x20), // calldata start
                          mload(_calldata),     // calldata length
                          ptr,                  // write output over free memory
                          0x20                  // uint256 return
                      )
                      if gt(success, 0) {
                          // Check number of bytes returned from last function call
                          switch returndatasize
                          // No bytes returned: assume success
                          case 0 {
                              ret := 1
                          }
                          // 32 bytes returned: check if non-zero
                          case 0x20 {
                              // Only return success if returned data was true
                              // Already have output in ptr
                              ret := eq(mload(ptr), 1)
                          }
                          // Not sure what was returned: don't mark as success
                          default { }
                      }
                  }
                  return ret;
              }
              function staticInvoke(address _addr, bytes memory _calldata)
                  private
                  view
                  returns (bool, uint256)
              {
                  bool success;
                  uint256 ret;
                  assembly {
                      let ptr := mload(0x40)    // free memory pointer
                      success := staticcall(
                          gas,                  // forward all gas
                          _addr,                // address
                          add(_calldata, 0x20), // calldata start
                          mload(_calldata),     // calldata length
                          ptr,                  // write output over free memory
                          0x20                  // uint256 return
                      )
                      if gt(success, 0) {
                          ret := mload(ptr)
                      }
                  }
                  return (success, ret);
              }
              /**
              * @dev Same as a standards-compliant ERC20.transfer() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeTransfer(ERC20 _token, address _to, uint256 _amount) internal returns (bool) {
                  bytes memory transferCallData = abi.encodeWithSelector(
                      TRANSFER_SELECTOR,
                      _to,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, transferCallData);
              }
              /**
              * @dev Same as a standards-compliant ERC20.transferFrom() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeTransferFrom(ERC20 _token, address _from, address _to, uint256 _amount) internal returns (bool) {
                  bytes memory transferFromCallData = abi.encodeWithSelector(
                      _token.transferFrom.selector,
                      _from,
                      _to,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, transferFromCallData);
              }
              /**
              * @dev Same as a standards-compliant ERC20.approve() that never reverts (returns false).
              *      Note that this makes an external call to the token.
              */
              function safeApprove(ERC20 _token, address _spender, uint256 _amount) internal returns (bool) {
                  bytes memory approveCallData = abi.encodeWithSelector(
                      _token.approve.selector,
                      _spender,
                      _amount
                  );
                  return invokeAndCheckSuccess(_token, approveCallData);
              }
              /**
              * @dev Static call into ERC20.balanceOf().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticBalanceOf(ERC20 _token, address _owner) internal view returns (uint256) {
                  bytes memory balanceOfCallData = abi.encodeWithSelector(
                      _token.balanceOf.selector,
                      _owner
                  );
                  (bool success, uint256 tokenBalance) = staticInvoke(_token, balanceOfCallData);
                  require(success, ERROR_TOKEN_BALANCE_REVERTED);
                  return tokenBalance;
              }
              /**
              * @dev Static call into ERC20.allowance().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticAllowance(ERC20 _token, address _owner, address _spender) internal view returns (uint256) {
                  bytes memory allowanceCallData = abi.encodeWithSelector(
                      _token.allowance.selector,
                      _owner,
                      _spender
                  );
                  (bool success, uint256 allowance) = staticInvoke(_token, allowanceCallData);
                  require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);
                  return allowance;
              }
              /**
              * @dev Static call into ERC20.totalSupply().
              * Reverts if the call fails for some reason (should never fail).
              */
              function staticTotalSupply(ERC20 _token) internal view returns (uint256) {
                  bytes memory totalSupplyCallData = abi.encodeWithSelector(_token.totalSupply.selector);
                  (bool success, uint256 totalSupply) = staticInvoke(_token, totalSupplyCallData);
                  require(success, ERROR_TOKEN_ALLOWANCE_REVERTED);
                  return totalSupply;
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./Uint256Helpers.sol";
          contract TimeHelpers {
              using Uint256Helpers for uint256;
              /**
              * @dev Returns the current block number.
              *      Using a function rather than `block.number` allows us to easily mock the block number in
              *      tests.
              */
              function getBlockNumber() internal view returns (uint256) {
                  return block.number;
              }
              /**
              * @dev Returns the current block number, converted to uint64.
              *      Using a function rather than `block.number` allows us to easily mock the block number in
              *      tests.
              */
              function getBlockNumber64() internal view returns (uint64) {
                  return getBlockNumber().toUint64();
              }
              /**
              * @dev Returns the current timestamp.
              *      Using a function rather than `block.timestamp` allows us to easily mock it in
              *      tests.
              */
              function getTimestamp() internal view returns (uint256) {
                  return block.timestamp; // solium-disable-line security/no-block-members
              }
              /**
              * @dev Returns the current timestamp, converted to uint64.
              *      Using a function rather than `block.timestamp` allows us to easily mock it in
              *      tests.
              */
              function getTimestamp64() internal view returns (uint64) {
                  return getTimestamp().toUint64();
              }
          }
          pragma solidity ^0.4.24;
          library Uint256Helpers {
              uint256 private constant MAX_UINT64 = uint64(-1);
              string private constant ERROR_NUMBER_TOO_BIG = "UINT64_NUMBER_TOO_BIG";
              function toUint64(uint256 a) internal pure returns (uint64) {
                  require(a <= MAX_UINT64, ERROR_NUMBER_TOO_BIG);
                  return uint64(a);
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          library UnstructuredStorage {
              function getStorageBool(bytes32 position) internal view returns (bool data) {
                  assembly { data := sload(position) }
              }
              function getStorageAddress(bytes32 position) internal view returns (address data) {
                  assembly { data := sload(position) }
              }
              function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
                  assembly { data := sload(position) }
              }
              function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
                  assembly { data := sload(position) }
              }
              function setStorageBool(bytes32 position, bool data) internal {
                  assembly { sstore(position, data) }
              }
              function setStorageAddress(bytes32 position, address data) internal {
                  assembly { sstore(position, data) }
              }
              function setStorageBytes32(bytes32 position, bytes32 data) internal {
                  assembly { sstore(position, data) }
              }
              function setStorageUint256(bytes32 position, uint256 data) internal {
                  assembly { sstore(position, data) }
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "../lib/token/ERC20.sol";
          import "./EtherTokenConstant.sol";
          import "./IsContract.sol";
          import "./IVaultRecoverable.sol";
          import "./SafeERC20.sol";
          contract VaultRecoverable is IVaultRecoverable, EtherTokenConstant, IsContract {
              using SafeERC20 for ERC20;
              string private constant ERROR_DISALLOWED = "RECOVER_DISALLOWED";
              string private constant ERROR_VAULT_NOT_CONTRACT = "RECOVER_VAULT_NOT_CONTRACT";
              string private constant ERROR_TOKEN_TRANSFER_FAILED = "RECOVER_TOKEN_TRANSFER_FAILED";
              /**
               * @notice Send funds to recovery Vault. This contract should never receive funds,
               *         but in case it does, this function allows one to recover them.
               * @param _token Token balance to be sent to recovery vault.
               */
              function transferToVault(address _token) external {
                  require(allowRecoverability(_token), ERROR_DISALLOWED);
                  address vault = getRecoveryVault();
                  require(isContract(vault), ERROR_VAULT_NOT_CONTRACT);
                  uint256 balance;
                  if (_token == ETH) {
                      balance = address(this).balance;
                      vault.transfer(balance);
                  } else {
                      ERC20 token = ERC20(_token);
                      balance = token.staticBalanceOf(this);
                      require(token.safeTransfer(vault, balance), ERROR_TOKEN_TRANSFER_FAILED);
                  }
                  emit RecoverToVault(vault, _token, balance);
              }
              /**
              * @dev By default deriving from AragonApp makes it recoverable
              * @param token Token address that would be recovered
              * @return bool whether the app allows the recovery
              */
              function allowRecoverability(address token) public view returns (bool) {
                  return true;
              }
              // Cast non-implemented interface to be public so we can use it internally
              function getRecoveryVault() public view returns (address);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./IEVMScriptExecutor.sol";
          import "./IEVMScriptRegistry.sol";
          import "../apps/AppStorage.sol";
          import "../kernel/KernelConstants.sol";
          import "../common/Initializable.sol";
          contract EVMScriptRunner is AppStorage, Initializable, EVMScriptRegistryConstants, KernelNamespaceConstants {
              string private constant ERROR_EXECUTOR_UNAVAILABLE = "EVMRUN_EXECUTOR_UNAVAILABLE";
              string private constant ERROR_PROTECTED_STATE_MODIFIED = "EVMRUN_PROTECTED_STATE_MODIFIED";
              /* This is manually crafted in assembly
              string private constant ERROR_EXECUTOR_INVALID_RETURN = "EVMRUN_EXECUTOR_INVALID_RETURN";
              */
              event ScriptResult(address indexed executor, bytes script, bytes input, bytes returnData);
              function getEVMScriptExecutor(bytes _script) public view returns (IEVMScriptExecutor) {
                  return IEVMScriptExecutor(getEVMScriptRegistry().getScriptExecutor(_script));
              }
              function getEVMScriptRegistry() public view returns (IEVMScriptRegistry) {
                  address registryAddr = kernel().getApp(KERNEL_APP_ADDR_NAMESPACE, EVMSCRIPT_REGISTRY_APP_ID);
                  return IEVMScriptRegistry(registryAddr);
              }
              function runScript(bytes _script, bytes _input, address[] _blacklist)
                  internal
                  isInitialized
                  protectState
                  returns (bytes)
              {
                  IEVMScriptExecutor executor = getEVMScriptExecutor(_script);
                  require(address(executor) != address(0), ERROR_EXECUTOR_UNAVAILABLE);
                  bytes4 sig = executor.execScript.selector;
                  bytes memory data = abi.encodeWithSelector(sig, _script, _input, _blacklist);
                  bytes memory output;
                  assembly {
                      let success := delegatecall(
                          gas,                // forward all gas
                          executor,           // address
                          add(data, 0x20),    // calldata start
                          mload(data),        // calldata length
                          0,                  // don't write output (we'll handle this ourselves)
                          0                   // don't write output
                      )
                      output := mload(0x40) // free mem ptr get
                      switch success
                      case 0 {
                          // If the call errored, forward its full error data
                          returndatacopy(output, 0, returndatasize)
                          revert(output, returndatasize)
                      }
                      default {
                          switch gt(returndatasize, 0x3f)
                          case 0 {
                              // Need at least 0x40 bytes returned for properly ABI-encoded bytes values,
                              // revert with "EVMRUN_EXECUTOR_INVALID_RETURN"
                              // See remix: doing a `revert("EVMRUN_EXECUTOR_INVALID_RETURN")` always results in
                              // this memory layout
                              mstore(output, 0x08c379a000000000000000000000000000000000000000000000000000000000)         // error identifier
                              mstore(add(output, 0x04), 0x0000000000000000000000000000000000000000000000000000000000000020) // starting offset
                              mstore(add(output, 0x24), 0x000000000000000000000000000000000000000000000000000000000000001e) // reason length
                              mstore(add(output, 0x44), 0x45564d52554e5f4558454355544f525f494e56414c49445f52455455524e0000) // reason
                              revert(output, 100) // 100 = 4 + 3 * 32 (error identifier + 3 words for the ABI encoded error)
                          }
                          default {
                              // Copy result
                              //
                              // Needs to perform an ABI decode for the expected `bytes` return type of
                              // `executor.execScript()` as solidity will automatically ABI encode the returned bytes as:
                              //    [ position of the first dynamic length return value = 0x20 (32 bytes) ]
                              //    [ output length (32 bytes) ]
                              //    [ output content (N bytes) ]
                              //
                              // Perform the ABI decode by ignoring the first 32 bytes of the return data
                              let copysize := sub(returndatasize, 0x20)
                              returndatacopy(output, 0x20, copysize)
                              mstore(0x40, add(output, copysize)) // free mem ptr set
                          }
                      }
                  }
                  emit ScriptResult(address(executor), _script, _input, output);
                  return output;
              }
              modifier protectState {
                  address preKernel = address(kernel());
                  bytes32 preAppId = appId();
                  _; // exec
                  require(address(kernel()) == preKernel, ERROR_PROTECTED_STATE_MODIFIED);
                  require(appId() == preAppId, ERROR_PROTECTED_STATE_MODIFIED);
              }
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          interface IEVMScriptExecutor {
              function execScript(bytes script, bytes input, address[] blacklist) external returns (bytes);
              function executorType() external pure returns (bytes32);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "./IEVMScriptExecutor.sol";
          contract EVMScriptRegistryConstants {
              /* Hardcoded constants to save gas
              bytes32 internal constant EVMSCRIPT_REGISTRY_APP_ID = apmNamehash("evmreg");
              */
              bytes32 internal constant EVMSCRIPT_REGISTRY_APP_ID = 0xddbcfd564f642ab5627cf68b9b7d374fb4f8a36e941a75d89c87998cef03bd61;
          }
          interface IEVMScriptRegistry {
              function addScriptExecutor(IEVMScriptExecutor executor) external returns (uint id);
              function disableScriptExecutor(uint256 executorId) external;
              // TODO: this should be external
              // See https://github.com/ethereum/solidity/issues/4832
              function getScriptExecutor(bytes script) public view returns (IEVMScriptExecutor);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          import "../acl/IACL.sol";
          import "../common/IVaultRecoverable.sol";
          interface IKernelEvents {
              event SetApp(bytes32 indexed namespace, bytes32 indexed appId, address app);
          }
          // This should be an interface, but interfaces can't inherit yet :(
          contract IKernel is IKernelEvents, IVaultRecoverable {
              function acl() public view returns (IACL);
              function hasPermission(address who, address where, bytes32 what, bytes how) public view returns (bool);
              function setApp(bytes32 namespace, bytes32 appId, address app) public;
              function getApp(bytes32 namespace, bytes32 appId) public view returns (address);
          }
          /*
           * SPDX-License-Identifier:    MIT
           */
          pragma solidity ^0.4.24;
          contract KernelAppIds {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_APP_ID = apmNamehash("kernel");
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = apmNamehash("acl");
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = apmNamehash("vault");
              */
              bytes32 internal constant KERNEL_CORE_APP_ID = 0x3b4bf6bf3ad5000ecf0f989d5befde585c6860fea3e574a4fab4c49d1c177d9c;
              bytes32 internal constant KERNEL_DEFAULT_ACL_APP_ID = 0xe3262375f45a6e2026b7e7b18c2b807434f2508fe1a2a3dfb493c7df8f4aad6a;
              bytes32 internal constant KERNEL_DEFAULT_VAULT_APP_ID = 0x7e852e0fcfce6551c13800f1e7476f982525c2b5277ba14b24339c68416336d1;
          }
          contract KernelNamespaceConstants {
              /* Hardcoded constants to save gas
              bytes32 internal constant KERNEL_CORE_NAMESPACE = keccak256("core");
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = keccak256("base");
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = keccak256("app");
              */
              bytes32 internal constant KERNEL_CORE_NAMESPACE = 0xc681a85306374a5ab27f0bbc385296a54bcd314a1948b6cf61c4ea1bc44bb9f8;
              bytes32 internal constant KERNEL_APP_BASES_NAMESPACE = 0xf1f3eb40f5bc1ad1344716ced8b8a0431d840b5783aea1fd01786bc26f35ac0f;
              bytes32 internal constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
          }
          // See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/d51e38758e1d985661534534d5c61e27bece5042/contracts/math/SafeMath.sol
          // Adapted to use pragma ^0.4.24 and satisfy our linter rules
          pragma solidity ^0.4.24;
          /**
           * @title SafeMath
           * @dev Math operations with safety checks that revert on error
           */
          library SafeMath {
              string private constant ERROR_ADD_OVERFLOW = "MATH_ADD_OVERFLOW";
              string private constant ERROR_SUB_UNDERFLOW = "MATH_SUB_UNDERFLOW";
              string private constant ERROR_MUL_OVERFLOW = "MATH_MUL_OVERFLOW";
              string private constant ERROR_DIV_ZERO = "MATH_DIV_ZERO";
              /**
              * @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, ERROR_MUL_OVERFLOW);
                  return c;
              }
              /**
              * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
              */
              function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
                  require(_b > 0, ERROR_DIV_ZERO); // Solidity only automatically asserts when dividing by 0
                  uint256 c = _a / _b;
                  // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
                  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, ERROR_SUB_UNDERFLOW);
                  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, ERROR_ADD_OVERFLOW);
                  return c;
              }
              /**
              * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
              * reverts when dividing by zero.
              */
              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                  require(b != 0, ERROR_DIV_ZERO);
                  return a % b;
              }
          }
          // See https://github.com/OpenZeppelin/openzeppelin-solidity/blob/a9f910d34f0ab33a1ae5e714f69f9596a02b4d91/contracts/token/ERC20/ERC20.sol
          pragma solidity ^0.4.24;
          /**
           * @title ERC20 interface
           * @dev see https://github.com/ethereum/EIPs/issues/20
           */
          contract ERC20 {
              function totalSupply() public view returns (uint256);
              function balanceOf(address _who) public view returns (uint256);
              function allowance(address _owner, address _spender)
                  public view returns (uint256);
              function transfer(address _to, uint256 _value) public returns (bool);
              function approve(address _spender, uint256 _value)
                  public returns (bool);
              function transferFrom(address _from, address _to, uint256 _value)
                  public returns (bool);
              event Transfer(
                  address indexed from,
                  address indexed to,
                  uint256 value
              );
              event Approval(
                  address indexed owner,
                  address indexed spender,
                  uint256 value
              );
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          /* See contracts/COMPILERS.md */
          pragma solidity 0.4.24;
          import "@aragon/os/contracts/common/UnstructuredStorage.sol";
          //
          // We need to pack four variables into the same 256bit-wide storage slot
          // to lower the costs per each staking request.
          //
          // As a result, slot's memory aligned as follows:
          //
          // MSB ------------------------------------------------------------------------------> LSB
          // 256____________160_________________________128_______________32_____________________ 0
          // |_______________|___________________________|________________|_______________________|
          // | maxStakeLimit | maxStakeLimitGrowthBlocks | prevStakeLimit | prevStakeBlockNumber  |
          // |<-- 96 bits -->|<---------- 32 bits ------>|<-- 96 bits --->|<----- 32 bits ------->|
          //
          //
          // NB: Internal representation conventions:
          //
          // - the `maxStakeLimitGrowthBlocks` field above represented as follows:
          // `maxStakeLimitGrowthBlocks` = `maxStakeLimit` / `stakeLimitIncreasePerBlock`
          //           32 bits                 96 bits               96 bits
          //
          //
          // - the "staking paused" state is encoded by `prevStakeBlockNumber` being zero,
          // - the "staking unlimited" state is encoded by `maxStakeLimit` being zero and `prevStakeBlockNumber` being non-zero.
          //
          /**
          * @notice Library for the internal structs definitions
          * @dev solidity <0.6 doesn't support top-level structs
          * using the library to have a proper namespace
          */
          library StakeLimitState {
              /**
                * @dev Internal representation struct (slot-wide)
                */
              struct Data {
                  uint32 prevStakeBlockNumber;      // block number of the previous stake submit
                  uint96 prevStakeLimit;            // limit value (<= `maxStakeLimit`) obtained on the previous stake submit
                  uint32 maxStakeLimitGrowthBlocks; // limit regeneration speed expressed in blocks
                  uint96 maxStakeLimit;             // maximum limit value
              }
          }
          library StakeLimitUnstructuredStorage {
              using UnstructuredStorage for bytes32;
              /// @dev Storage offset for `maxStakeLimit` (bits)
              uint256 internal constant MAX_STAKE_LIMIT_OFFSET = 160;
              /// @dev Storage offset for `maxStakeLimitGrowthBlocks` (bits)
              uint256 internal constant MAX_STAKE_LIMIT_GROWTH_BLOCKS_OFFSET = 128;
              /// @dev Storage offset for `prevStakeLimit` (bits)
              uint256 internal constant PREV_STAKE_LIMIT_OFFSET = 32;
              /// @dev Storage offset for `prevStakeBlockNumber` (bits)
              uint256 internal constant PREV_STAKE_BLOCK_NUMBER_OFFSET = 0;
              /**
              * @dev Read stake limit state from the unstructured storage position
              * @param _position storage offset
              */
              function getStorageStakeLimitStruct(bytes32 _position) internal view returns (StakeLimitState.Data memory stakeLimit) {
                  uint256 slotValue = _position.getStorageUint256();
                  stakeLimit.prevStakeBlockNumber = uint32(slotValue >> PREV_STAKE_BLOCK_NUMBER_OFFSET);
                  stakeLimit.prevStakeLimit = uint96(slotValue >> PREV_STAKE_LIMIT_OFFSET);
                  stakeLimit.maxStakeLimitGrowthBlocks = uint32(slotValue >> MAX_STAKE_LIMIT_GROWTH_BLOCKS_OFFSET);
                  stakeLimit.maxStakeLimit = uint96(slotValue >> MAX_STAKE_LIMIT_OFFSET);
              }
               /**
              * @dev Write stake limit state to the unstructured storage position
              * @param _position storage offset
              * @param _data stake limit state structure instance
              */
              function setStorageStakeLimitStruct(bytes32 _position, StakeLimitState.Data memory _data) internal {
                  _position.setStorageUint256(
                      uint256(_data.prevStakeBlockNumber) << PREV_STAKE_BLOCK_NUMBER_OFFSET
                          | uint256(_data.prevStakeLimit) << PREV_STAKE_LIMIT_OFFSET
                          | uint256(_data.maxStakeLimitGrowthBlocks) << MAX_STAKE_LIMIT_GROWTH_BLOCKS_OFFSET
                          | uint256(_data.maxStakeLimit) << MAX_STAKE_LIMIT_OFFSET
                  );
              }
          }
          /**
          * @notice Interface library with helper functions to deal with stake limit struct in a more high-level approach.
          */
          library StakeLimitUtils {
              /**
              * @notice Calculate stake limit for the current block.
              * @dev using `_constGasMin` to make gas consumption independent of the current block number
              */
              function calculateCurrentStakeLimit(StakeLimitState.Data memory _data) internal view returns(uint256 limit) {
                  uint256 stakeLimitIncPerBlock;
                  if (_data.maxStakeLimitGrowthBlocks != 0) {
                      stakeLimitIncPerBlock = _data.maxStakeLimit / _data.maxStakeLimitGrowthBlocks;
                  }
                  uint256 blocksPassed = block.number - _data.prevStakeBlockNumber;
                  uint256 projectedLimit = _data.prevStakeLimit + blocksPassed * stakeLimitIncPerBlock;
                  limit = _constGasMin(
                      projectedLimit,
                      _data.maxStakeLimit
                  );
              }
              /**
              * @notice check if staking is on pause
              */
              function isStakingPaused(StakeLimitState.Data memory _data) internal pure returns(bool) {
                  return _data.prevStakeBlockNumber == 0;
              }
              /**
              * @notice check if staking limit is set (otherwise staking is unlimited)
              */
              function isStakingLimitSet(StakeLimitState.Data memory _data) internal pure returns(bool) {
                  return _data.maxStakeLimit != 0;
              }
              /**
              * @notice update stake limit repr with the desired limits
              * @dev input `_data` param is mutated and the func returns effectively the same pointer
              * @param _data stake limit state struct
              * @param _maxStakeLimit stake limit max value
              * @param _stakeLimitIncreasePerBlock stake limit increase (restoration) per block
              */
              function setStakingLimit(
                  StakeLimitState.Data memory _data,
                  uint256 _maxStakeLimit,
                  uint256 _stakeLimitIncreasePerBlock
              ) internal view returns (StakeLimitState.Data memory) {
                  require(_maxStakeLimit != 0, "ZERO_MAX_STAKE_LIMIT");
                  require(_maxStakeLimit <= uint96(-1), "TOO_LARGE_MAX_STAKE_LIMIT");
                  require(_maxStakeLimit >= _stakeLimitIncreasePerBlock, "TOO_LARGE_LIMIT_INCREASE");
                  require(
                      (_stakeLimitIncreasePerBlock == 0)
                      || (_maxStakeLimit / _stakeLimitIncreasePerBlock <= uint32(-1)),
                      "TOO_SMALL_LIMIT_INCREASE"
                  );
                  // reset prev stake limit to the new max stake limit if
                  if (
                      // staking was paused or
                      _data.prevStakeBlockNumber == 0 ||
                      // staking was unlimited or
                      _data.maxStakeLimit == 0 ||
                      // new maximum limit value is lower than the value obtained on the previous stake submit
                      _maxStakeLimit < _data.prevStakeLimit
                  ) {
                      _data.prevStakeLimit = uint96(_maxStakeLimit);
                  }
                  _data.maxStakeLimitGrowthBlocks =
                      _stakeLimitIncreasePerBlock != 0 ? uint32(_maxStakeLimit / _stakeLimitIncreasePerBlock) : 0;
                  _data.maxStakeLimit = uint96(_maxStakeLimit);
                  if (_data.prevStakeBlockNumber != 0) {
                      _data.prevStakeBlockNumber = uint32(block.number);
                  }
                  return _data;
              }
              /**
              * @notice update stake limit repr to remove the limit
              * @dev input `_data` param is mutated and the func returns effectively the same pointer
              * @param _data stake limit state struct
              */
              function removeStakingLimit(
                  StakeLimitState.Data memory _data
              ) internal pure returns (StakeLimitState.Data memory) {
                  _data.maxStakeLimit = 0;
                  return _data;
              }
              /**
              * @notice update stake limit repr after submitting user's eth
              * @dev input `_data` param is mutated and the func returns effectively the same pointer
              * @param _data stake limit state struct
              * @param _newPrevStakeLimit new value for the `prevStakeLimit` field
              */
              function updatePrevStakeLimit(
                  StakeLimitState.Data memory _data,
                  uint256 _newPrevStakeLimit
              ) internal view returns (StakeLimitState.Data memory) {
                  assert(_newPrevStakeLimit <= uint96(-1));
                  assert(_data.prevStakeBlockNumber != 0);
                  _data.prevStakeLimit = uint96(_newPrevStakeLimit);
                  _data.prevStakeBlockNumber = uint32(block.number);
                  return _data;
              }
              /**
              * @notice set stake limit pause state (on or off)
              * @dev input `_data` param is mutated and the func returns effectively the same pointer
              * @param _data stake limit state struct
              * @param _isPaused pause state flag
              */
              function setStakeLimitPauseState(
                  StakeLimitState.Data memory _data,
                  bool _isPaused
              ) internal view returns (StakeLimitState.Data memory) {
                  _data.prevStakeBlockNumber = uint32(_isPaused ? 0 : block.number);
                  return _data;
              }
              /**
               * @notice find a minimum of two numbers with a constant gas consumption
               * @dev doesn't use branching logic inside
               * @param _lhs left hand side value
               * @param _rhs right hand side value
               */
              function _constGasMin(uint256 _lhs, uint256 _rhs) internal pure returns (uint256 min) {
                  uint256 lhsIsLess;
                  assembly {
                      lhsIsLess := lt(_lhs, _rhs) // lhsIsLess = (_lhs < _rhs) ? 1 : 0
                  }
                  min = (_lhs * lhsIsLess) + (_rhs * (1 - lhsIsLess));
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          /* See contracts/COMPILERS.md */
          pragma solidity 0.4.24;
          import "@aragon/os/contracts/apps/AragonApp.sol";
          import "@aragon/os/contracts/lib/math/SafeMath.sol";
          import "../common/interfaces/ILidoLocator.sol";
          import "../common/interfaces/IBurner.sol";
          import "./lib/StakeLimitUtils.sol";
          import "../common/lib/Math256.sol";
          import "./StETHPermit.sol";
          import "./utils/Versioned.sol";
          interface IPostTokenRebaseReceiver {
              function handlePostTokenRebase(
                  uint256 _reportTimestamp,
                  uint256 _timeElapsed,
                  uint256 _preTotalShares,
                  uint256 _preTotalEther,
                  uint256 _postTotalShares,
                  uint256 _postTotalEther,
                  uint256 _sharesMintedAsFees
              ) external;
          }
          interface IOracleReportSanityChecker {
              function checkAccountingOracleReport(
                  uint256 _timeElapsed,
                  uint256 _preCLBalance,
                  uint256 _postCLBalance,
                  uint256 _withdrawalVaultBalance,
                  uint256 _elRewardsVaultBalance,
                  uint256 _sharesRequestedToBurn,
                  uint256 _preCLValidators,
                  uint256 _postCLValidators
              ) external view;
              function smoothenTokenRebase(
                  uint256 _preTotalPooledEther,
                  uint256 _preTotalShares,
                  uint256 _preCLBalance,
                  uint256 _postCLBalance,
                  uint256 _withdrawalVaultBalance,
                  uint256 _elRewardsVaultBalance,
                  uint256 _sharesRequestedToBurn,
                  uint256 _etherToLockForWithdrawals,
                  uint256 _newSharesToBurnForWithdrawals
              ) external view returns (
                  uint256 withdrawals,
                  uint256 elRewards,
                  uint256 simulatedSharesToBurn,
                  uint256 sharesToBurn
              );
              function checkWithdrawalQueueOracleReport(
                  uint256 _lastFinalizableRequestId,
                  uint256 _reportTimestamp
              ) external view;
              function checkSimulatedShareRate(
                  uint256 _postTotalPooledEther,
                  uint256 _postTotalShares,
                  uint256 _etherLockedOnWithdrawalQueue,
                  uint256 _sharesBurntDueToWithdrawals,
                  uint256 _simulatedShareRate
              ) external view;
          }
          interface ILidoExecutionLayerRewardsVault {
              function withdrawRewards(uint256 _maxAmount) external returns (uint256 amount);
          }
          interface IWithdrawalVault {
              function withdrawWithdrawals(uint256 _amount) external;
          }
          interface IStakingRouter {
              function deposit(
                  uint256 _depositsCount,
                  uint256 _stakingModuleId,
                  bytes _depositCalldata
              ) external payable;
              function getStakingRewardsDistribution()
                  external
                  view
                  returns (
                      address[] memory recipients,
                      uint256[] memory stakingModuleIds,
                      uint96[] memory stakingModuleFees,
                      uint96 totalFee,
                      uint256 precisionPoints
                  );
              function getWithdrawalCredentials() external view returns (bytes32);
              function reportRewardsMinted(uint256[] _stakingModuleIds, uint256[] _totalShares) external;
              function getTotalFeeE4Precision() external view returns (uint16 totalFee);
              function getStakingFeeAggregateDistributionE4Precision() external view returns (
                  uint16 modulesFee, uint16 treasuryFee
              );
              function getStakingModuleMaxDepositsCount(uint256 _stakingModuleId, uint256 _maxDepositsValue)
                  external
                  view
                  returns (uint256);
              function TOTAL_BASIS_POINTS() external view returns (uint256);
          }
          interface IWithdrawalQueue {
              function prefinalize(uint256[] _batches, uint256 _maxShareRate)
                  external
                  view
                  returns (uint256 ethToLock, uint256 sharesToBurn);
              function finalize(uint256 _lastIdToFinalize, uint256 _maxShareRate) external payable;
              function isPaused() external view returns (bool);
              function unfinalizedStETH() external view returns (uint256);
              function isBunkerModeActive() external view returns (bool);
          }
          /**
          * @title Liquid staking pool implementation
          *
          * Lido is an Ethereum liquid staking protocol solving the problem of frozen staked ether on Consensus Layer
          * being unavailable for transfers and DeFi on Execution Layer.
          *
          * Since balances of all token holders change when the amount of total pooled Ether
          * changes, this token cannot fully implement ERC20 standard: it only emits `Transfer`
          * events upon explicit transfer between holders. In contrast, when Lido oracle reports
          * rewards, no Transfer events are generated: doing so would require emitting an event
          * for each token holder and thus running an unbounded loop.
          *
          * ---
          * NB: Order of inheritance must preserve the structured storage layout of the previous versions.
          *
          * @dev Lido is derived from `StETHPermit` that has a structured storage:
          * SLOT 0: mapping (address => uint256) private shares (`StETH`)
          * SLOT 1: mapping (address => mapping (address => uint256)) private allowances (`StETH`)
          * SLOT 2: mapping(address => uint256) internal noncesByAddress (`StETHPermit`)
          *
          * `Versioned` and `AragonApp` both don't have the pre-allocated structured storage.
          */
          contract Lido is Versioned, StETHPermit, AragonApp {
              using SafeMath for uint256;
              using UnstructuredStorage for bytes32;
              using StakeLimitUnstructuredStorage for bytes32;
              using StakeLimitUtils for StakeLimitState.Data;
              /// ACL
              bytes32 public constant PAUSE_ROLE =
                  0x139c2898040ef16910dc9f44dc697df79363da767d8bc92f2e310312b816e46d; // keccak256("PAUSE_ROLE");
              bytes32 public constant RESUME_ROLE =
                  0x2fc10cc8ae19568712f7a176fb4978616a610650813c9d05326c34abb62749c7; // keccak256("RESUME_ROLE");
              bytes32 public constant STAKING_PAUSE_ROLE =
                  0x84ea57490227bc2be925c684e2a367071d69890b629590198f4125a018eb1de8; // keccak256("STAKING_PAUSE_ROLE")
              bytes32 public constant STAKING_CONTROL_ROLE =
                  0xa42eee1333c0758ba72be38e728b6dadb32ea767de5b4ddbaea1dae85b1b051f; // keccak256("STAKING_CONTROL_ROLE")
              bytes32 public constant UNSAFE_CHANGE_DEPOSITED_VALIDATORS_ROLE =
                  0xe6dc5d79630c61871e99d341ad72c5a052bed2fc8c79e5a4480a7cd31117576c; // keccak256("UNSAFE_CHANGE_DEPOSITED_VALIDATORS_ROLE")
              uint256 private constant DEPOSIT_SIZE = 32 ether;
              /// @dev storage slot position for the Lido protocol contracts locator
              bytes32 internal constant LIDO_LOCATOR_POSITION =
                  0x9ef78dff90f100ea94042bd00ccb978430524befc391d3e510b5f55ff3166df7; // keccak256("lido.Lido.lidoLocator")
              /// @dev storage slot position of the staking rate limit structure
              bytes32 internal constant STAKING_STATE_POSITION =
                  0xa3678de4a579be090bed1177e0a24f77cc29d181ac22fd7688aca344d8938015; // keccak256("lido.Lido.stakeLimit");
              /// @dev amount of Ether (on the current Ethereum side) buffered on this smart contract balance
              bytes32 internal constant BUFFERED_ETHER_POSITION =
                  0xed310af23f61f96daefbcd140b306c0bdbf8c178398299741687b90e794772b0; // keccak256("lido.Lido.bufferedEther");
              /// @dev number of deposited validators (incrementing counter of deposit operations).
              bytes32 internal constant DEPOSITED_VALIDATORS_POSITION =
                  0xe6e35175eb53fc006520a2a9c3e9711a7c00de6ff2c32dd31df8c5a24cac1b5c; // keccak256("lido.Lido.depositedValidators");
              /// @dev total amount of ether on Consensus Layer (sum of all the balances of Lido validators)
              // "beacon" in the `keccak256()` parameter is staying here for compatibility reason
              bytes32 internal constant CL_BALANCE_POSITION =
                  0xa66d35f054e68143c18f32c990ed5cb972bb68a68f500cd2dd3a16bbf3686483; // keccak256("lido.Lido.beaconBalance");
              /// @dev number of Lido's validators available in the Consensus Layer state
              // "beacon" in the `keccak256()` parameter is staying here for compatibility reason
              bytes32 internal constant CL_VALIDATORS_POSITION =
                  0x9f70001d82b6ef54e9d3725b46581c3eb9ee3aa02b941b6aa54d678a9ca35b10; // keccak256("lido.Lido.beaconValidators");
              /// @dev Just a counter of total amount of execution layer rewards received by Lido contract. Not used in the logic.
              bytes32 internal constant TOTAL_EL_REWARDS_COLLECTED_POSITION =
                  0xafe016039542d12eec0183bb0b1ffc2ca45b027126a494672fba4154ee77facb; // keccak256("lido.Lido.totalELRewardsCollected");
              // Staking was paused (don't accept user's ether submits)
              event StakingPaused();
              // Staking was resumed (accept user's ether submits)
              event StakingResumed();
              // Staking limit was set (rate limits user's submits)
              event StakingLimitSet(uint256 maxStakeLimit, uint256 stakeLimitIncreasePerBlock);
              // Staking limit was removed
              event StakingLimitRemoved();
              // Emits when validators number delivered by the oracle
              event CLValidatorsUpdated(
                  uint256 indexed reportTimestamp,
                  uint256 preCLValidators,
                  uint256 postCLValidators
              );
              // Emits when var at `DEPOSITED_VALIDATORS_POSITION` changed
              event DepositedValidatorsChanged(
                  uint256 depositedValidators
              );
              // Emits when oracle accounting report processed
              event ETHDistributed(
                  uint256 indexed reportTimestamp,
                  uint256 preCLBalance,
                  uint256 postCLBalance,
                  uint256 withdrawalsWithdrawn,
                  uint256 executionLayerRewardsWithdrawn,
                  uint256 postBufferedEther
              );
              // Emits when token rebased (total supply and/or total shares were changed)
              event TokenRebased(
                  uint256 indexed reportTimestamp,
                  uint256 timeElapsed,
                  uint256 preTotalShares,
                  uint256 preTotalEther,
                  uint256 postTotalShares,
                  uint256 postTotalEther,
                  uint256 sharesMintedAsFees
              );
              // Lido locator set
              event LidoLocatorSet(address lidoLocator);
              // The amount of ETH withdrawn from LidoExecutionLayerRewardsVault to Lido
              event ELRewardsReceived(uint256 amount);
              // The amount of ETH withdrawn from WithdrawalVault to Lido
              event WithdrawalsReceived(uint256 amount);
              // Records a deposit made by a user
              event Submitted(address indexed sender, uint256 amount, address referral);
              // The `amount` of ether was sent to the deposit_contract.deposit function
              event Unbuffered(uint256 amount);
              /**
              * @dev As AragonApp, Lido contract must be initialized with following variables:
              *      NB: by default, staking and the whole Lido pool are in paused state
              *
              * The contract's balance must be non-zero to allow initial holder bootstrap.
              *
              * @param _lidoLocator lido locator contract
              * @param _eip712StETH eip712 helper contract for StETH
              */
              function initialize(address _lidoLocator, address _eip712StETH)
                  public
                  payable
                  onlyInit
              {
                  _bootstrapInitialHolder();
                  _initialize_v2(_lidoLocator, _eip712StETH);
                  initialized();
              }
              /**
               * initializer for the Lido version "2"
               */
              function _initialize_v2(address _lidoLocator, address _eip712StETH) internal {
                  _setContractVersion(2);
                  LIDO_LOCATOR_POSITION.setStorageAddress(_lidoLocator);
                  _initializeEIP712StETH(_eip712StETH);
                  // set infinite allowance for burner from withdrawal queue
                  // to burn finalized requests' shares
                  _approve(
                      ILidoLocator(_lidoLocator).withdrawalQueue(),
                      ILidoLocator(_lidoLocator).burner(),
                      INFINITE_ALLOWANCE
                  );
                  emit LidoLocatorSet(_lidoLocator);
              }
              /**
               * @notice A function to finalize upgrade to v2 (from v1). Can be called only once
               * @dev Value "1" in CONTRACT_VERSION_POSITION is skipped due to change in numbering
               *
               * The initial protocol token holder must exist.
               *
               * For more details see https://github.com/lidofinance/lido-improvement-proposals/blob/develop/LIPS/lip-10.md
               */
              function finalizeUpgrade_v2(address _lidoLocator, address _eip712StETH) external {
                  _checkContractVersion(0);
                  require(hasInitialized(), "NOT_INITIALIZED");
                  require(_lidoLocator != address(0), "LIDO_LOCATOR_ZERO_ADDRESS");
                  require(_eip712StETH != address(0), "EIP712_STETH_ZERO_ADDRESS");
                  require(_sharesOf(INITIAL_TOKEN_HOLDER) != 0, "INITIAL_HOLDER_EXISTS");
                  _initialize_v2(_lidoLocator, _eip712StETH);
              }
              /**
               * @notice Stops accepting new Ether to the protocol
               *
               * @dev While accepting new Ether is stopped, calls to the `submit` function,
               * as well as to the default payable function, will revert.
               *
               * Emits `StakingPaused` event.
               */
              function pauseStaking() external {
                  _auth(STAKING_PAUSE_ROLE);
                  _pauseStaking();
              }
              /**
               * @notice Resumes accepting new Ether to the protocol (if `pauseStaking` was called previously)
               * NB: Staking could be rate-limited by imposing a limit on the stake amount
               * at each moment in time, see `setStakingLimit()` and `removeStakingLimit()`
               *
               * @dev Preserves staking limit if it was set previously
               *
               * Emits `StakingResumed` event
               */
              function resumeStaking() external {
                  _auth(STAKING_CONTROL_ROLE);
                  require(hasInitialized(), "NOT_INITIALIZED");
                  _resumeStaking();
              }
              /**
               * @notice Sets the staking rate limit
               *
               * ▲ Stake limit
               * │.....  .....   ........ ...            ....     ... Stake limit = max
               * │      .       .        .   .   .      .    . . .
               * │     .       .              . .  . . .      . .
               * │            .                .  . . .
               * │──────────────────────────────────────────────────> Time
               * │     ^      ^          ^   ^^^  ^ ^ ^     ^^^ ^     Stake events
               *
               * @dev Reverts if:
               * - `_maxStakeLimit` == 0
               * - `_maxStakeLimit` >= 2^96
               * - `_maxStakeLimit` < `_stakeLimitIncreasePerBlock`
               * - `_maxStakeLimit` / `_stakeLimitIncreasePerBlock` >= 2^32 (only if `_stakeLimitIncreasePerBlock` != 0)
               *
               * Emits `StakingLimitSet` event
               *
               * @param _maxStakeLimit max stake limit value
               * @param _stakeLimitIncreasePerBlock stake limit increase per single block
               */
              function setStakingLimit(uint256 _maxStakeLimit, uint256 _stakeLimitIncreasePerBlock) external {
                  _auth(STAKING_CONTROL_ROLE);
                  STAKING_STATE_POSITION.setStorageStakeLimitStruct(
                      STAKING_STATE_POSITION.getStorageStakeLimitStruct().setStakingLimit(_maxStakeLimit, _stakeLimitIncreasePerBlock)
                  );
                  emit StakingLimitSet(_maxStakeLimit, _stakeLimitIncreasePerBlock);
              }
              /**
               * @notice Removes the staking rate limit
               *
               * Emits `StakingLimitRemoved` event
               */
              function removeStakingLimit() external {
                  _auth(STAKING_CONTROL_ROLE);
                  STAKING_STATE_POSITION.setStorageStakeLimitStruct(STAKING_STATE_POSITION.getStorageStakeLimitStruct().removeStakingLimit());
                  emit StakingLimitRemoved();
              }
              /**
               * @notice Check staking state: whether it's paused or not
               */
              function isStakingPaused() external view returns (bool) {
                  return STAKING_STATE_POSITION.getStorageStakeLimitStruct().isStakingPaused();
              }
              /**
               * @notice Returns how much Ether can be staked in the current block
               * @dev Special return values:
               * - 2^256 - 1 if staking is unlimited;
               * - 0 if staking is paused or if limit is exhausted.
               */
              function getCurrentStakeLimit() external view returns (uint256) {
                  return _getCurrentStakeLimit(STAKING_STATE_POSITION.getStorageStakeLimitStruct());
              }
              /**
               * @notice Returns full info about current stake limit params and state
               * @dev Might be used for the advanced integration requests.
               * @return isStakingPaused staking pause state (equivalent to return of isStakingPaused())
               * @return isStakingLimitSet whether the stake limit is set
               * @return currentStakeLimit current stake limit (equivalent to return of getCurrentStakeLimit())
               * @return maxStakeLimit max stake limit
               * @return maxStakeLimitGrowthBlocks blocks needed to restore max stake limit from the fully exhausted state
               * @return prevStakeLimit previously reached stake limit
               * @return prevStakeBlockNumber previously seen block number
               */
              function getStakeLimitFullInfo()
                  external
                  view
                  returns (
                      bool isStakingPaused,
                      bool isStakingLimitSet,
                      uint256 currentStakeLimit,
                      uint256 maxStakeLimit,
                      uint256 maxStakeLimitGrowthBlocks,
                      uint256 prevStakeLimit,
                      uint256 prevStakeBlockNumber
                  )
              {
                  StakeLimitState.Data memory stakeLimitData = STAKING_STATE_POSITION.getStorageStakeLimitStruct();
                  isStakingPaused = stakeLimitData.isStakingPaused();
                  isStakingLimitSet = stakeLimitData.isStakingLimitSet();
                  currentStakeLimit = _getCurrentStakeLimit(stakeLimitData);
                  maxStakeLimit = stakeLimitData.maxStakeLimit;
                  maxStakeLimitGrowthBlocks = stakeLimitData.maxStakeLimitGrowthBlocks;
                  prevStakeLimit = stakeLimitData.prevStakeLimit;
                  prevStakeBlockNumber = stakeLimitData.prevStakeBlockNumber;
              }
              /**
              * @notice Send funds to the pool
              * @dev Users are able to submit their funds by transacting to the fallback function.
              * Unlike vanilla Ethereum Deposit contract, accepting only 32-Ether transactions, Lido
              * accepts payments of any size. Submitted Ethers are stored in Buffer until someone calls
              * deposit() and pushes them to the Ethereum Deposit contract.
              */
              // solhint-disable-next-line no-complex-fallback
              function() external payable {
                  // protection against accidental submissions by calling non-existent function
                  require(msg.data.length == 0, "NON_EMPTY_DATA");
                  _submit(0);
              }
              /**
               * @notice Send funds to the pool with optional _referral parameter
               * @dev This function is alternative way to submit funds. Supports optional referral address.
               * @return Amount of StETH shares generated
               */
              function submit(address _referral) external payable returns (uint256) {
                  return _submit(_referral);
              }
              /**
               * @notice A payable function for execution layer rewards. Can be called only by `ExecutionLayerRewardsVault`
               * @dev We need a dedicated function because funds received by the default payable function
               * are treated as a user deposit
               */
              function receiveELRewards() external payable {
                  require(msg.sender == getLidoLocator().elRewardsVault());
                  TOTAL_EL_REWARDS_COLLECTED_POSITION.setStorageUint256(getTotalELRewardsCollected().add(msg.value));
                  emit ELRewardsReceived(msg.value);
              }
              /**
              * @notice A payable function for withdrawals acquisition. Can be called only by `WithdrawalVault`
              * @dev We need a dedicated function because funds received by the default payable function
              * are treated as a user deposit
              */
              function receiveWithdrawals() external payable {
                  require(msg.sender == getLidoLocator().withdrawalVault());
                  emit WithdrawalsReceived(msg.value);
              }
              /**
               * @notice Stop pool routine operations
               */
              function stop() external {
                  _auth(PAUSE_ROLE);
                  _stop();
                  _pauseStaking();
              }
              /**
               * @notice Resume pool routine operations
               * @dev Staking is resumed after this call using the previously set limits (if any)
               */
              function resume() external {
                  _auth(RESUME_ROLE);
                  _resume();
                  _resumeStaking();
              }
              /**
               * The structure is used to aggregate the `handleOracleReport` provided data.
               * @dev Using the in-memory structure addresses `stack too deep` issues.
               */
              struct OracleReportedData {
                  // Oracle timings
                  uint256 reportTimestamp;
                  uint256 timeElapsed;
                  // CL values
                  uint256 clValidators;
                  uint256 postCLBalance;
                  // EL values
                  uint256 withdrawalVaultBalance;
                  uint256 elRewardsVaultBalance;
                  uint256 sharesRequestedToBurn;
                  // Decision about withdrawals processing
                  uint256[] withdrawalFinalizationBatches;
                  uint256 simulatedShareRate;
              }
              /**
               * The structure is used to preload the contract using `getLidoLocator()` via single call
               */
              struct OracleReportContracts {
                  address accountingOracle;
                  address elRewardsVault;
                  address oracleReportSanityChecker;
                  address burner;
                  address withdrawalQueue;
                  address withdrawalVault;
                  address postTokenRebaseReceiver;
              }
              /**
              * @notice Updates accounting stats, collects EL rewards and distributes collected rewards
              *         if beacon balance increased, performs withdrawal requests finalization
              * @dev periodically called by the AccountingOracle contract
              *
              * @param _reportTimestamp the moment of the oracle report calculation
              * @param _timeElapsed seconds elapsed since the previous report calculation
              * @param _clValidators number of Lido validators on Consensus Layer
              * @param _clBalance sum of all Lido validators' balances on Consensus Layer
              * @param _withdrawalVaultBalance withdrawal vault balance on Execution Layer at `_reportTimestamp`
              * @param _elRewardsVaultBalance elRewards vault balance on Execution Layer at `_reportTimestamp`
              * @param _sharesRequestedToBurn shares requested to burn through Burner at `_reportTimestamp`
              * @param _withdrawalFinalizationBatches the ascendingly-sorted array of withdrawal request IDs obtained by calling
              * WithdrawalQueue.calculateFinalizationBatches. Empty array means that no withdrawal requests should be finalized
              * @param _simulatedShareRate share rate that was simulated by oracle when the report data created (1e27 precision)
              *
              * NB: `_simulatedShareRate` should be calculated off-chain by calling the method with `eth_call` JSON-RPC API
              * while passing empty `_withdrawalFinalizationBatches` and `_simulatedShareRate` == 0, plugging the returned values
              * to the following formula: `_simulatedShareRate = (postTotalPooledEther * 1e27) / postTotalShares`
              *
              * @return postRebaseAmounts[0]: `postTotalPooledEther` amount of ether in the protocol after report
              * @return postRebaseAmounts[1]: `postTotalShares` amount of shares in the protocol after report
              * @return postRebaseAmounts[2]: `withdrawals` withdrawn from the withdrawals vault
              * @return postRebaseAmounts[3]: `elRewards` withdrawn from the execution layer rewards vault
              */
              function handleOracleReport(
                  // Oracle timings
                  uint256 _reportTimestamp,
                  uint256 _timeElapsed,
                  // CL values
                  uint256 _clValidators,
                  uint256 _clBalance,
                  // EL values
                  uint256 _withdrawalVaultBalance,
                  uint256 _elRewardsVaultBalance,
                  uint256 _sharesRequestedToBurn,
                  // Decision about withdrawals processing
                  uint256[] _withdrawalFinalizationBatches,
                  uint256 _simulatedShareRate
              ) external returns (uint256[4] postRebaseAmounts) {
                  _whenNotStopped();
                  return _handleOracleReport(
                      OracleReportedData(
                          _reportTimestamp,
                          _timeElapsed,
                          _clValidators,
                          _clBalance,
                          _withdrawalVaultBalance,
                          _elRewardsVaultBalance,
                          _sharesRequestedToBurn,
                          _withdrawalFinalizationBatches,
                          _simulatedShareRate
                      )
                  );
              }
              /**
               * @notice Unsafely change deposited validators
               *
               * The method unsafely changes deposited validator counter.
               * Can be required when onboarding external validators to Lido
               * (i.e., had deposited before and rotated their type-0x00 withdrawal credentials to Lido)
               *
               * @param _newDepositedValidators new value
               */
              function unsafeChangeDepositedValidators(uint256 _newDepositedValidators) external {
                  _auth(UNSAFE_CHANGE_DEPOSITED_VALIDATORS_ROLE);
                  DEPOSITED_VALIDATORS_POSITION.setStorageUint256(_newDepositedValidators);
                  emit DepositedValidatorsChanged(_newDepositedValidators);
              }
              /**
               * @notice Overrides default AragonApp behaviour to disallow recovery.
               */
              function transferToVault(address /* _token */) external {
                  revert("NOT_SUPPORTED");
              }
              /**
              * @notice Get the amount of Ether temporary buffered on this contract balance
              * @dev Buffered balance is kept on the contract from the moment the funds are received from user
              * until the moment they are actually sent to the official Deposit contract.
              * @return amount of buffered funds in wei
              */
              function getBufferedEther() external view returns (uint256) {
                  return _getBufferedEther();
              }
              /**
               * @notice Get total amount of execution layer rewards collected to Lido contract
               * @dev Ether got through LidoExecutionLayerRewardsVault is kept on this contract's balance the same way
               * as other buffered Ether is kept (until it gets deposited)
               * @return amount of funds received as execution layer rewards in wei
               */
              function getTotalELRewardsCollected() public view returns (uint256) {
                  return TOTAL_EL_REWARDS_COLLECTED_POSITION.getStorageUint256();
              }
              /**
               * @notice Gets authorized oracle address
               * @return address of oracle contract
               */
              function getLidoLocator() public view returns (ILidoLocator) {
                  return ILidoLocator(LIDO_LOCATOR_POSITION.getStorageAddress());
              }
              /**
              * @notice Returns the key values related to Consensus Layer side of the contract. It historically contains beacon
              * @return depositedValidators - number of deposited validators from Lido contract side
              * @return beaconValidators - number of Lido validators visible on Consensus Layer, reported by oracle
              * @return beaconBalance - total amount of ether on the Consensus Layer side (sum of all the balances of Lido validators)
              *
              * @dev `beacon` in naming still here for historical reasons
              */
              function getBeaconStat() external view returns (uint256 depositedValidators, uint256 beaconValidators, uint256 beaconBalance) {
                  depositedValidators = DEPOSITED_VALIDATORS_POSITION.getStorageUint256();
                  beaconValidators = CL_VALIDATORS_POSITION.getStorageUint256();
                  beaconBalance = CL_BALANCE_POSITION.getStorageUint256();
              }
              /**
               * @dev Check that Lido allows depositing buffered ether to the consensus layer
               * Depends on the bunker state and protocol's pause state
               */
              function canDeposit() public view returns (bool) {
                  return !_withdrawalQueue().isBunkerModeActive() && !isStopped();
              }
              /**
               * @dev Returns depositable ether amount.
               * Takes into account unfinalized stETH required by WithdrawalQueue
               */
              function getDepositableEther() public view returns (uint256) {
                  uint256 bufferedEther = _getBufferedEther();
                  uint256 withdrawalReserve = _withdrawalQueue().unfinalizedStETH();
                  return bufferedEther > withdrawalReserve ? bufferedEther - withdrawalReserve : 0;
              }
              /**
               * @dev Invokes a deposit call to the Staking Router contract and updates buffered counters
               * @param _maxDepositsCount max deposits count
               * @param _stakingModuleId id of the staking module to be deposited
               * @param _depositCalldata module calldata
               */
              function deposit(uint256 _maxDepositsCount, uint256 _stakingModuleId, bytes _depositCalldata) external {
                  ILidoLocator locator = getLidoLocator();
                  require(msg.sender == locator.depositSecurityModule(), "APP_AUTH_DSM_FAILED");
                  require(canDeposit(), "CAN_NOT_DEPOSIT");
                  IStakingRouter stakingRouter = _stakingRouter();
                  uint256 depositsCount = Math256.min(
                      _maxDepositsCount,
                      stakingRouter.getStakingModuleMaxDepositsCount(_stakingModuleId, getDepositableEther())
                  );
                  uint256 depositsValue;
                  if (depositsCount > 0) {
                      depositsValue = depositsCount.mul(DEPOSIT_SIZE);
                      /// @dev firstly update the local state of the contract to prevent a reentrancy attack,
                      ///     even if the StakingRouter is a trusted contract.
                      BUFFERED_ETHER_POSITION.setStorageUint256(_getBufferedEther().sub(depositsValue));
                      emit Unbuffered(depositsValue);
                      uint256 newDepositedValidators = DEPOSITED_VALIDATORS_POSITION.getStorageUint256().add(depositsCount);
                      DEPOSITED_VALIDATORS_POSITION.setStorageUint256(newDepositedValidators);
                      emit DepositedValidatorsChanged(newDepositedValidators);
                  }
                  /// @dev transfer ether to StakingRouter and make a deposit at the same time. All the ether
                  ///     sent to StakingRouter is counted as deposited. If StakingRouter can't deposit all
                  ///     passed ether it MUST revert the whole transaction (never happens in normal circumstances)
                  stakingRouter.deposit.value(depositsValue)(depositsCount, _stakingModuleId, _depositCalldata);
              }
              /// DEPRECATED PUBLIC METHODS
              /**
               * @notice Returns current withdrawal credentials of deposited validators
               * @dev DEPRECATED: use StakingRouter.getWithdrawalCredentials() instead
               */
              function getWithdrawalCredentials() external view returns (bytes32) {
                  return _stakingRouter().getWithdrawalCredentials();
              }
              /**
               * @notice Returns legacy oracle
               * @dev DEPRECATED: the `AccountingOracle` superseded the old one
               */
              function getOracle() external view returns (address) {
                  return getLidoLocator().legacyOracle();
              }
              /**
               * @notice Returns the treasury address
               * @dev DEPRECATED: use LidoLocator.treasury()
               */
              function getTreasury() external view returns (address) {
                  return _treasury();
              }
              /**
               * @notice Returns current staking rewards fee rate
               * @dev DEPRECATED: Now fees information is stored in StakingRouter and
               * with higher precision. Use StakingRouter.getStakingFeeAggregateDistribution() instead.
               * @return totalFee total rewards fee in 1e4 precision (10000 is 100%). The value might be
               * inaccurate because the actual value is truncated here to 1e4 precision.
               */
              function getFee() external view returns (uint16 totalFee) {
                  totalFee = _stakingRouter().getTotalFeeE4Precision();
              }
              /**
               * @notice Returns current fee distribution, values relative to the total fee (getFee())
               * @dev DEPRECATED: Now fees information is stored in StakingRouter and
               * with higher precision. Use StakingRouter.getStakingFeeAggregateDistribution() instead.
               * @return treasuryFeeBasisPoints return treasury fee in TOTAL_BASIS_POINTS (10000 is 100% fee) precision
               * @return insuranceFeeBasisPoints always returns 0 because the capability to send fees to
               * insurance from Lido contract is removed.
               * @return operatorsFeeBasisPoints return total fee for all operators of all staking modules in
               * TOTAL_BASIS_POINTS (10000 is 100% fee) precision.
               * Previously returned total fee of all node operators of NodeOperatorsRegistry (Curated staking module now)
               * The value might be inaccurate because the actual value is truncated here to 1e4 precision.
               */
              function getFeeDistribution()
                  external view
                  returns (
                      uint16 treasuryFeeBasisPoints,
                      uint16 insuranceFeeBasisPoints,
                      uint16 operatorsFeeBasisPoints
                  )
              {
                  IStakingRouter stakingRouter = _stakingRouter();
                  uint256 totalBasisPoints = stakingRouter.TOTAL_BASIS_POINTS();
                  uint256 totalFee = stakingRouter.getTotalFeeE4Precision();
                  (uint256 treasuryFeeBasisPointsAbs, uint256 operatorsFeeBasisPointsAbs) = stakingRouter
                      .getStakingFeeAggregateDistributionE4Precision();
                  insuranceFeeBasisPoints = 0;  // explicitly set to zero
                  treasuryFeeBasisPoints = uint16((treasuryFeeBasisPointsAbs * totalBasisPoints) / totalFee);
                  operatorsFeeBasisPoints = uint16((operatorsFeeBasisPointsAbs * totalBasisPoints) / totalFee);
              }
              /*
               * @dev updates Consensus Layer state snapshot according to the current report
               *
               * NB: conventions and assumptions
               *
               * `depositedValidators` are total amount of the **ever** deposited Lido validators
               * `_postClValidators` are total amount of the **ever** appeared on the CL side Lido validators
               *
               * i.e., exited Lido validators persist in the state, just with a different status
               */
              function _processClStateUpdate(
                  uint256 _reportTimestamp,
                  uint256 _preClValidators,
                  uint256 _postClValidators,
                  uint256 _postClBalance
              ) internal returns (uint256 preCLBalance) {
                  uint256 depositedValidators = DEPOSITED_VALIDATORS_POSITION.getStorageUint256();
                  require(_postClValidators <= depositedValidators, "REPORTED_MORE_DEPOSITED");
                  require(_postClValidators >= _preClValidators, "REPORTED_LESS_VALIDATORS");
                  if (_postClValidators > _preClValidators) {
                      CL_VALIDATORS_POSITION.setStorageUint256(_postClValidators);
                  }
                  uint256 appearedValidators = _postClValidators - _preClValidators;
                  preCLBalance = CL_BALANCE_POSITION.getStorageUint256();
                  // Take into account the balance of the newly appeared validators
                  preCLBalance = preCLBalance.add(appearedValidators.mul(DEPOSIT_SIZE));
                  // Save the current CL balance and validators to
                  // calculate rewards on the next push
                  CL_BALANCE_POSITION.setStorageUint256(_postClBalance);
                  emit CLValidatorsUpdated(_reportTimestamp, _preClValidators, _postClValidators);
              }
              /**
               * @dev collect ETH from ELRewardsVault and WithdrawalVault, then send to WithdrawalQueue
               */
              function _collectRewardsAndProcessWithdrawals(
                  OracleReportContracts memory _contracts,
                  uint256 _withdrawalsToWithdraw,
                  uint256 _elRewardsToWithdraw,
                  uint256[] _withdrawalFinalizationBatches,
                  uint256 _simulatedShareRate,
                  uint256 _etherToLockOnWithdrawalQueue
              ) internal {
                  // withdraw execution layer rewards and put them to the buffer
                  if (_elRewardsToWithdraw > 0) {
                      ILidoExecutionLayerRewardsVault(_contracts.elRewardsVault).withdrawRewards(_elRewardsToWithdraw);
                  }
                  // withdraw withdrawals and put them to the buffer
                  if (_withdrawalsToWithdraw > 0) {
                      IWithdrawalVault(_contracts.withdrawalVault).withdrawWithdrawals(_withdrawalsToWithdraw);
                  }
                  // finalize withdrawals (send ether, assign shares for burning)
                  if (_etherToLockOnWithdrawalQueue > 0) {
                      IWithdrawalQueue withdrawalQueue = IWithdrawalQueue(_contracts.withdrawalQueue);
                      withdrawalQueue.finalize.value(_etherToLockOnWithdrawalQueue)(
                          _withdrawalFinalizationBatches[_withdrawalFinalizationBatches.length - 1],
                          _simulatedShareRate
                      );
                  }
                  uint256 postBufferedEther = _getBufferedEther()
                      .add(_elRewardsToWithdraw) // Collected from ELVault
                      .add(_withdrawalsToWithdraw) // Collected from WithdrawalVault
                      .sub(_etherToLockOnWithdrawalQueue); // Sent to WithdrawalQueue
                  _setBufferedEther(postBufferedEther);
              }
              /**
               * @dev return amount to lock on withdrawal queue and shares to burn
               * depending on the finalization batch parameters
               */
              function _calculateWithdrawals(
                  OracleReportContracts memory _contracts,
                  OracleReportedData memory _reportedData
              ) internal view returns (
                  uint256 etherToLock, uint256 sharesToBurn
              ) {
                  IWithdrawalQueue withdrawalQueue = IWithdrawalQueue(_contracts.withdrawalQueue);
                  if (!withdrawalQueue.isPaused()) {
                      IOracleReportSanityChecker(_contracts.oracleReportSanityChecker).checkWithdrawalQueueOracleReport(
                          _reportedData.withdrawalFinalizationBatches[_reportedData.withdrawalFinalizationBatches.length - 1],
                          _reportedData.reportTimestamp
                      );
                      (etherToLock, sharesToBurn) = withdrawalQueue.prefinalize(
                          _reportedData.withdrawalFinalizationBatches,
                          _reportedData.simulatedShareRate
                      );
                  }
              }
              /**
               * @dev calculate the amount of rewards and distribute it
               */
              function _processRewards(
                  OracleReportContext memory _reportContext,
                  uint256 _postCLBalance,
                  uint256 _withdrawnWithdrawals,
                  uint256 _withdrawnElRewards
              ) internal returns (uint256 sharesMintedAsFees) {
                  uint256 postCLTotalBalance = _postCLBalance.add(_withdrawnWithdrawals);
                  // Don’t mint/distribute any protocol fee on the non-profitable Lido oracle report
                  // (when consensus layer balance delta is zero or negative).
                  // See LIP-12 for details:
                  // https://research.lido.fi/t/lip-12-on-chain-part-of-the-rewards-distribution-after-the-merge/1625
                  if (postCLTotalBalance > _reportContext.preCLBalance) {
                      uint256 consensusLayerRewards = postCLTotalBalance - _reportContext.preCLBalance;
                      sharesMintedAsFees = _distributeFee(
                          _reportContext.preTotalPooledEther,
                          _reportContext.preTotalShares,
                          consensusLayerRewards.add(_withdrawnElRewards)
                      );
                  }
              }
              /**
               * @dev Process user deposit, mints liquid tokens and increase the pool buffer
               * @param _referral address of referral.
               * @return amount of StETH shares generated
               */
              function _submit(address _referral) internal returns (uint256) {
                  require(msg.value != 0, "ZERO_DEPOSIT");
                  StakeLimitState.Data memory stakeLimitData = STAKING_STATE_POSITION.getStorageStakeLimitStruct();
                  // There is an invariant that protocol pause also implies staking pause.
                  // Thus, no need to check protocol pause explicitly.
                  require(!stakeLimitData.isStakingPaused(), "STAKING_PAUSED");
                  if (stakeLimitData.isStakingLimitSet()) {
                      uint256 currentStakeLimit = stakeLimitData.calculateCurrentStakeLimit();
                      require(msg.value <= currentStakeLimit, "STAKE_LIMIT");
                      STAKING_STATE_POSITION.setStorageStakeLimitStruct(stakeLimitData.updatePrevStakeLimit(currentStakeLimit - msg.value));
                  }
                  uint256 sharesAmount = getSharesByPooledEth(msg.value);
                  _mintShares(msg.sender, sharesAmount);
                  _setBufferedEther(_getBufferedEther().add(msg.value));
                  emit Submitted(msg.sender, msg.value, _referral);
                  _emitTransferAfterMintingShares(msg.sender, sharesAmount);
                  return sharesAmount;
              }
              /**
               * @dev Staking router rewards distribution.
               *
               * Corresponds to the return value of `IStakingRouter.newTotalPooledEtherForRewards()`
               * Prevents `stack too deep` issue.
               */
              struct StakingRewardsDistribution {
                  address[] recipients;
                  uint256[] moduleIds;
                  uint96[] modulesFees;
                  uint96 totalFee;
                  uint256 precisionPoints;
              }
              /**
               * @dev Get staking rewards distribution from staking router.
               */
              function _getStakingRewardsDistribution() internal view returns (
                  StakingRewardsDistribution memory ret,
                  IStakingRouter router
              ) {
                  router = _stakingRouter();
                  (
                      ret.recipients,
                      ret.moduleIds,
                      ret.modulesFees,
                      ret.totalFee,
                      ret.precisionPoints
                  ) = router.getStakingRewardsDistribution();
                  require(ret.recipients.length == ret.modulesFees.length, "WRONG_RECIPIENTS_INPUT");
                  require(ret.moduleIds.length == ret.modulesFees.length, "WRONG_MODULE_IDS_INPUT");
              }
              /**
               * @dev Distributes fee portion of the rewards by minting and distributing corresponding amount of liquid tokens.
               * @param _preTotalPooledEther Total supply before report-induced changes applied
               * @param _preTotalShares Total shares before report-induced changes applied
               * @param _totalRewards Total rewards accrued both on the Execution Layer and the Consensus Layer sides in wei.
               */
              function _distributeFee(
                  uint256 _preTotalPooledEther,
                  uint256 _preTotalShares,
                  uint256 _totalRewards
              ) internal returns (uint256 sharesMintedAsFees) {
                  // We need to take a defined percentage of the reported reward as a fee, and we do
                  // this by minting new token shares and assigning them to the fee recipients (see
                  // StETH docs for the explanation of the shares mechanics). The staking rewards fee
                  // is defined in basis points (1 basis point is equal to 0.01%, 10000 (TOTAL_BASIS_POINTS) is 100%).
                  //
                  // Since we are increasing totalPooledEther by _totalRewards (totalPooledEtherWithRewards),
                  // the combined cost of all holders' shares has became _totalRewards StETH tokens more,
                  // effectively splitting the reward between each token holder proportionally to their token share.
                  //
                  // Now we want to mint new shares to the fee recipient, so that the total cost of the
                  // newly-minted shares exactly corresponds to the fee taken:
                  //
                  // totalPooledEtherWithRewards = _preTotalPooledEther + _totalRewards
                  // shares2mint * newShareCost = (_totalRewards * totalFee) / PRECISION_POINTS
                  // newShareCost = totalPooledEtherWithRewards / (_preTotalShares + shares2mint)
                  //
                  // which follows to:
                  //
                  //                        _totalRewards * totalFee * _preTotalShares
                  // shares2mint = --------------------------------------------------------------
                  //                 (totalPooledEtherWithRewards * PRECISION_POINTS) - (_totalRewards * totalFee)
                  //
                  // The effect is that the given percentage of the reward goes to the fee recipient, and
                  // the rest of the reward is distributed between token holders proportionally to their
                  // token shares.
                  (
                      StakingRewardsDistribution memory rewardsDistribution,
                      IStakingRouter router
                  ) = _getStakingRewardsDistribution();
                  if (rewardsDistribution.totalFee > 0) {
                      uint256 totalPooledEtherWithRewards = _preTotalPooledEther.add(_totalRewards);
                      sharesMintedAsFees =
                          _totalRewards.mul(rewardsDistribution.totalFee).mul(_preTotalShares).div(
                              totalPooledEtherWithRewards.mul(
                                  rewardsDistribution.precisionPoints
                              ).sub(_totalRewards.mul(rewardsDistribution.totalFee))
                          );
                      _mintShares(address(this), sharesMintedAsFees);
                      (uint256[] memory moduleRewards, uint256 totalModuleRewards) =
                          _transferModuleRewards(
                              rewardsDistribution.recipients,
                              rewardsDistribution.modulesFees,
                              rewardsDistribution.totalFee,
                              sharesMintedAsFees
                          );
                      _transferTreasuryRewards(sharesMintedAsFees.sub(totalModuleRewards));
                      router.reportRewardsMinted(
                          rewardsDistribution.moduleIds,
                          moduleRewards
                      );
                  }
              }
              function _transferModuleRewards(
                  address[] memory recipients,
                  uint96[] memory modulesFees,
                  uint256 totalFee,
                  uint256 totalRewards
              ) internal returns (uint256[] memory moduleRewards, uint256 totalModuleRewards) {
                  moduleRewards = new uint256[](recipients.length);
                  for (uint256 i; i < recipients.length; ++i) {
                      if (modulesFees[i] > 0) {
                          uint256 iModuleRewards = totalRewards.mul(modulesFees[i]).div(totalFee);
                          moduleRewards[i] = iModuleRewards;
                          _transferShares(address(this), recipients[i], iModuleRewards);
                          _emitTransferAfterMintingShares(recipients[i], iModuleRewards);
                          totalModuleRewards = totalModuleRewards.add(iModuleRewards);
                      }
                  }
              }
              function _transferTreasuryRewards(uint256 treasuryReward) internal {
                  address treasury = _treasury();
                  _transferShares(address(this), treasury, treasuryReward);
                  _emitTransferAfterMintingShares(treasury, treasuryReward);
              }
              /**
               * @dev Gets the amount of Ether temporary buffered on this contract balance
               */
              function _getBufferedEther() internal view returns (uint256) {
                  return BUFFERED_ETHER_POSITION.getStorageUint256();
              }
              function _setBufferedEther(uint256 _newBufferedEther) internal {
                  BUFFERED_ETHER_POSITION.setStorageUint256(_newBufferedEther);
              }
              /// @dev Calculates and returns the total base balance (multiple of 32) of validators in transient state,
              ///     i.e. submitted to the official Deposit contract but not yet visible in the CL state.
              /// @return transient balance in wei (1e-18 Ether)
              function _getTransientBalance() internal view returns (uint256) {
                  uint256 depositedValidators = DEPOSITED_VALIDATORS_POSITION.getStorageUint256();
                  uint256 clValidators = CL_VALIDATORS_POSITION.getStorageUint256();
                  // clValidators can never be less than deposited ones.
                  assert(depositedValidators >= clValidators);
                  return (depositedValidators - clValidators).mul(DEPOSIT_SIZE);
              }
              /**
               * @dev Gets the total amount of Ether controlled by the system
               * @return total balance in wei
               */
              function _getTotalPooledEther() internal view returns (uint256) {
                  return _getBufferedEther()
                      .add(CL_BALANCE_POSITION.getStorageUint256())
                      .add(_getTransientBalance());
              }
              function _pauseStaking() internal {
                  STAKING_STATE_POSITION.setStorageStakeLimitStruct(
                      STAKING_STATE_POSITION.getStorageStakeLimitStruct().setStakeLimitPauseState(true)
                  );
                  emit StakingPaused();
              }
              function _resumeStaking() internal {
                  STAKING_STATE_POSITION.setStorageStakeLimitStruct(
                      STAKING_STATE_POSITION.getStorageStakeLimitStruct().setStakeLimitPauseState(false)
                  );
                  emit StakingResumed();
              }
              function _getCurrentStakeLimit(StakeLimitState.Data memory _stakeLimitData) internal view returns (uint256) {
                  if (_stakeLimitData.isStakingPaused()) {
                      return 0;
                  }
                  if (!_stakeLimitData.isStakingLimitSet()) {
                      return uint256(-1);
                  }
                  return _stakeLimitData.calculateCurrentStakeLimit();
              }
              /**
               * @dev Size-efficient analog of the `auth(_role)` modifier
               * @param _role Permission name
               */
              function _auth(bytes32 _role) internal view {
                  require(canPerform(msg.sender, _role, new uint256[](0)), "APP_AUTH_FAILED");
              }
              /**
               * @dev Intermediate data structure for `_handleOracleReport`
               * Helps to overcome `stack too deep` issue.
               */
              struct OracleReportContext {
                  uint256 preCLValidators;
                  uint256 preCLBalance;
                  uint256 preTotalPooledEther;
                  uint256 preTotalShares;
                  uint256 etherToLockOnWithdrawalQueue;
                  uint256 sharesToBurnFromWithdrawalQueue;
                  uint256 simulatedSharesToBurn;
                  uint256 sharesToBurn;
                  uint256 sharesMintedAsFees;
              }
              /**
               * @dev Handle oracle report method operating with the data-packed structs
               * Using structs helps to overcome 'stack too deep' issue.
               *
               * The method updates the protocol's accounting state.
               * Key steps:
               * 1. Take a snapshot of the current (pre-) state
               * 2. Pass the report data to sanity checker (reverts if malformed)
               * 3. Pre-calculate the ether to lock for withdrawal queue and shares to be burnt
               * 4. Pass the accounting values to sanity checker to smoothen positive token rebase
               *    (i.e., postpone the extra rewards to be applied during the next rounds)
               * 5. Invoke finalization of the withdrawal requests
               * 6. Burn excess shares within the allowed limit (can postpone some shares to be burnt later)
               * 7. Distribute protocol fee (treasury & node operators)
               * 8. Complete token rebase by informing observers (emit an event and call the external receivers if any)
               * 9. Sanity check for the provided simulated share rate
               */
              function _handleOracleReport(OracleReportedData memory _reportedData) internal returns (uint256[4]) {
                  OracleReportContracts memory contracts = _loadOracleReportContracts();
                  require(msg.sender == contracts.accountingOracle, "APP_AUTH_FAILED");
                  require(_reportedData.reportTimestamp <= block.timestamp, "INVALID_REPORT_TIMESTAMP");
                  OracleReportContext memory reportContext;
                  // Step 1.
                  // Take a snapshot of the current (pre-) state
                  reportContext.preTotalPooledEther = _getTotalPooledEther();
                  reportContext.preTotalShares = _getTotalShares();
                  reportContext.preCLValidators = CL_VALIDATORS_POSITION.getStorageUint256();
                  reportContext.preCLBalance = _processClStateUpdate(
                      _reportedData.reportTimestamp,
                      reportContext.preCLValidators,
                      _reportedData.clValidators,
                      _reportedData.postCLBalance
                  );
                  // Step 2.
                  // Pass the report data to sanity checker (reverts if malformed)
                  _checkAccountingOracleReport(contracts, _reportedData, reportContext);
                  // Step 3.
                  // Pre-calculate the ether to lock for withdrawal queue and shares to be burnt
                  // due to withdrawal requests to finalize
                  if (_reportedData.withdrawalFinalizationBatches.length != 0) {
                      (
                          reportContext.etherToLockOnWithdrawalQueue,
                          reportContext.sharesToBurnFromWithdrawalQueue
                      ) = _calculateWithdrawals(contracts, _reportedData);
                      if (reportContext.sharesToBurnFromWithdrawalQueue > 0) {
                          IBurner(contracts.burner).requestBurnShares(
                              contracts.withdrawalQueue,
                              reportContext.sharesToBurnFromWithdrawalQueue
                          );
                      }
                  }
                  // Step 4.
                  // Pass the accounting values to sanity checker to smoothen positive token rebase
                  uint256 withdrawals;
                  uint256 elRewards;
                  (
                      withdrawals, elRewards, reportContext.simulatedSharesToBurn, reportContext.sharesToBurn
                  ) = IOracleReportSanityChecker(contracts.oracleReportSanityChecker).smoothenTokenRebase(
                      reportContext.preTotalPooledEther,
                      reportContext.preTotalShares,
                      reportContext.preCLBalance,
                      _reportedData.postCLBalance,
                      _reportedData.withdrawalVaultBalance,
                      _reportedData.elRewardsVaultBalance,
                      _reportedData.sharesRequestedToBurn,
                      reportContext.etherToLockOnWithdrawalQueue,
                      reportContext.sharesToBurnFromWithdrawalQueue
                  );
                  // Step 5.
                  // Invoke finalization of the withdrawal requests (send ether to withdrawal queue, assign shares to be burnt)
                  _collectRewardsAndProcessWithdrawals(
                      contracts,
                      withdrawals,
                      elRewards,
                      _reportedData.withdrawalFinalizationBatches,
                      _reportedData.simulatedShareRate,
                      reportContext.etherToLockOnWithdrawalQueue
                  );
                  emit ETHDistributed(
                      _reportedData.reportTimestamp,
                      reportContext.preCLBalance,
                      _reportedData.postCLBalance,
                      withdrawals,
                      elRewards,
                      _getBufferedEther()
                  );
                  // Step 6.
                  // Burn the previously requested shares
                  if (reportContext.sharesToBurn > 0) {
                      IBurner(contracts.burner).commitSharesToBurn(reportContext.sharesToBurn);
                      _burnShares(contracts.burner, reportContext.sharesToBurn);
                  }
                  // Step 7.
                  // Distribute protocol fee (treasury & node operators)
                  reportContext.sharesMintedAsFees = _processRewards(
                      reportContext,
                      _reportedData.postCLBalance,
                      withdrawals,
                      elRewards
                  );
                  // Step 8.
                  // Complete token rebase by informing observers (emit an event and call the external receivers if any)
                  (
                      uint256 postTotalShares,
                      uint256 postTotalPooledEther
                  ) = _completeTokenRebase(
                      _reportedData,
                      reportContext,
                      IPostTokenRebaseReceiver(contracts.postTokenRebaseReceiver)
                  );
                  // Step 9. Sanity check for the provided simulated share rate
                  if (_reportedData.withdrawalFinalizationBatches.length != 0) {
                      IOracleReportSanityChecker(contracts.oracleReportSanityChecker).checkSimulatedShareRate(
                          postTotalPooledEther,
                          postTotalShares,
                          reportContext.etherToLockOnWithdrawalQueue,
                          reportContext.sharesToBurn.sub(reportContext.simulatedSharesToBurn),
                          _reportedData.simulatedShareRate
                      );
                  }
                  return [postTotalPooledEther, postTotalShares, withdrawals, elRewards];
              }
              /**
               * @dev Pass the provided oracle data to the sanity checker contract
               * Works with structures to overcome `stack too deep`
               */
              function _checkAccountingOracleReport(
                  OracleReportContracts memory _contracts,
                  OracleReportedData memory _reportedData,
                  OracleReportContext memory _reportContext
              ) internal view {
                  IOracleReportSanityChecker(_contracts.oracleReportSanityChecker).checkAccountingOracleReport(
                      _reportedData.timeElapsed,
                      _reportContext.preCLBalance,
                      _reportedData.postCLBalance,
                      _reportedData.withdrawalVaultBalance,
                      _reportedData.elRewardsVaultBalance,
                      _reportedData.sharesRequestedToBurn,
                      _reportContext.preCLValidators,
                      _reportedData.clValidators
                  );
              }
              /**
               * @dev Notify observers about the completed token rebase.
               * Emit events and call external receivers.
               */
              function _completeTokenRebase(
                  OracleReportedData memory _reportedData,
                  OracleReportContext memory _reportContext,
                  IPostTokenRebaseReceiver _postTokenRebaseReceiver
              ) internal returns (uint256 postTotalShares, uint256 postTotalPooledEther) {
                  postTotalShares = _getTotalShares();
                  postTotalPooledEther = _getTotalPooledEther();
                  if (_postTokenRebaseReceiver != address(0)) {
                      _postTokenRebaseReceiver.handlePostTokenRebase(
                          _reportedData.reportTimestamp,
                          _reportedData.timeElapsed,
                          _reportContext.preTotalShares,
                          _reportContext.preTotalPooledEther,
                          postTotalShares,
                          postTotalPooledEther,
                          _reportContext.sharesMintedAsFees
                      );
                  }
                  emit TokenRebased(
                      _reportedData.reportTimestamp,
                      _reportedData.timeElapsed,
                      _reportContext.preTotalShares,
                      _reportContext.preTotalPooledEther,
                      postTotalShares,
                      postTotalPooledEther,
                      _reportContext.sharesMintedAsFees
                  );
              }
              /**
               * @dev Load the contracts used for `handleOracleReport` internally.
               */
              function _loadOracleReportContracts() internal view returns (OracleReportContracts memory ret) {
                  (
                      ret.accountingOracle,
                      ret.elRewardsVault,
                      ret.oracleReportSanityChecker,
                      ret.burner,
                      ret.withdrawalQueue,
                      ret.withdrawalVault,
                      ret.postTokenRebaseReceiver
                  ) = getLidoLocator().oracleReportComponentsForLido();
              }
              function _stakingRouter() internal view returns (IStakingRouter) {
                  return IStakingRouter(getLidoLocator().stakingRouter());
              }
              function _withdrawalQueue() internal view returns (IWithdrawalQueue) {
                  return IWithdrawalQueue(getLidoLocator().withdrawalQueue());
              }
              function _treasury() internal view returns (address) {
                  return getLidoLocator().treasury();
              }
              /**
               * @notice Mints shares on behalf of 0xdead address,
               * the shares amount is equal to the contract's balance.     *
               *
               * Allows to get rid of zero checks for `totalShares` and `totalPooledEther`
               * and overcome corner cases.
               *
               * NB: reverts if the current contract's balance is zero.
               *
               * @dev must be invoked before using the token
               */
              function _bootstrapInitialHolder() internal {
                  uint256 balance = address(this).balance;
                  assert(balance != 0);
                  if (_getTotalShares() == 0) {
                      // if protocol is empty bootstrap it with the contract's balance
                      // address(0xdead) is a holder for initial shares
                      _setBufferedEther(balance);
                      // emitting `Submitted` before Transfer events to preserver events order in tx
                      emit Submitted(INITIAL_TOKEN_HOLDER, balance, 0);
                      _mintInitialShares(balance);
                  }
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          /* See contracts/COMPILERS.md */
          pragma solidity 0.4.24;
          import "openzeppelin-solidity/contracts/token/ERC20/IERC20.sol";
          import "@aragon/os/contracts/common/UnstructuredStorage.sol";
          import "@aragon/os/contracts/lib/math/SafeMath.sol";
          import "./utils/Pausable.sol";
          /**
           * @title Interest-bearing ERC20-like token for Lido Liquid Stacking protocol.
           *
           * This contract is abstract. To make the contract deployable override the
           * `_getTotalPooledEther` function. `Lido.sol` contract inherits StETH and defines
           * the `_getTotalPooledEther` function.
           *
           * StETH balances are dynamic and represent the holder's share in the total amount
           * of Ether controlled by the protocol. Account shares aren't normalized, so the
           * contract also stores the sum of all shares to calculate each account's token balance
           * which equals to:
           *
           *   shares[account] * _getTotalPooledEther() / _getTotalShares()
           *
           * For example, assume that we have:
           *
           *   _getTotalPooledEther() -> 10 ETH
           *   sharesOf(user1) -> 100
           *   sharesOf(user2) -> 400
           *
           * Therefore:
           *
           *   balanceOf(user1) -> 2 tokens which corresponds 2 ETH
           *   balanceOf(user2) -> 8 tokens which corresponds 8 ETH
           *
           * Since balances of all token holders change when the amount of total pooled Ether
           * changes, this token cannot fully implement ERC20 standard: it only emits `Transfer`
           * events upon explicit transfer between holders. In contrast, when total amount of
           * pooled Ether increases, no `Transfer` events are generated: doing so would require
           * emitting an event for each token holder and thus running an unbounded loop.
           *
           * The token inherits from `Pausable` and uses `whenNotStopped` modifier for methods
           * which change `shares` or `allowances`. `_stop` and `_resume` functions are overridden
           * in `Lido.sol` and might be called by an account with the `PAUSE_ROLE` assigned by the
           * DAO. This is useful for emergency scenarios, e.g. a protocol bug, where one might want
           * to freeze all token transfers and approvals until the emergency is resolved.
           */
          contract StETH is IERC20, Pausable {
              using SafeMath for uint256;
              using UnstructuredStorage for bytes32;
              address constant internal INITIAL_TOKEN_HOLDER = 0xdead;
              uint256 constant internal INFINITE_ALLOWANCE = ~uint256(0);
              /**
               * @dev StETH balances are dynamic and are calculated based on the accounts' shares
               * and the total amount of Ether controlled by the protocol. Account shares aren't
               * normalized, so the contract also stores the sum of all shares to calculate
               * each account's token balance which equals to:
               *
               *   shares[account] * _getTotalPooledEther() / _getTotalShares()
              */
              mapping (address => uint256) private shares;
              /**
               * @dev Allowances are nominated in tokens, not token shares.
               */
              mapping (address => mapping (address => uint256)) private allowances;
              /**
               * @dev Storage position used for holding the total amount of shares in existence.
               *
               * The Lido protocol is built on top of Aragon and uses the Unstructured Storage pattern
               * for value types:
               *
               * https://blog.openzeppelin.com/upgradeability-using-unstructured-storage
               * https://blog.8bitzen.com/posts/20-02-2020-understanding-how-solidity-upgradeable-unstructured-proxies-work
               *
               * For reference types, conventional storage variables are used since it's non-trivial
               * and error-prone to implement reference-type unstructured storage using Solidity v0.4;
               * see https://github.com/lidofinance/lido-dao/issues/181#issuecomment-736098834
               *
               * keccak256("lido.StETH.totalShares")
               */
              bytes32 internal constant TOTAL_SHARES_POSITION =
                  0xe3b4b636e601189b5f4c6742edf2538ac12bb61ed03e6da26949d69838fa447e;
              /**
                * @notice An executed shares transfer from `sender` to `recipient`.
                *
                * @dev emitted in pair with an ERC20-defined `Transfer` event.
                */
              event TransferShares(
                  address indexed from,
                  address indexed to,
                  uint256 sharesValue
              );
              /**
               * @notice An executed `burnShares` request
               *
               * @dev Reports simultaneously burnt shares amount
               * and corresponding stETH amount.
               * The stETH amount is calculated twice: before and after the burning incurred rebase.
               *
               * @param account holder of the burnt shares
               * @param preRebaseTokenAmount amount of stETH the burnt shares corresponded to before the burn
               * @param postRebaseTokenAmount amount of stETH the burnt shares corresponded to after the burn
               * @param sharesAmount amount of burnt shares
               */
              event SharesBurnt(
                  address indexed account,
                  uint256 preRebaseTokenAmount,
                  uint256 postRebaseTokenAmount,
                  uint256 sharesAmount
              );
              /**
               * @return the name of the token.
               */
              function name() external pure returns (string) {
                  return "Liquid staked Ether 2.0";
              }
              /**
               * @return the symbol of the token, usually a shorter version of the
               * name.
               */
              function symbol() external pure returns (string) {
                  return "stETH";
              }
              /**
               * @return the number of decimals for getting user representation of a token amount.
               */
              function decimals() external pure returns (uint8) {
                  return 18;
              }
              /**
               * @return the amount of tokens in existence.
               *
               * @dev Always equals to `_getTotalPooledEther()` since token amount
               * is pegged to the total amount of Ether controlled by the protocol.
               */
              function totalSupply() external view returns (uint256) {
                  return _getTotalPooledEther();
              }
              /**
               * @return the entire amount of Ether controlled by the protocol.
               *
               * @dev The sum of all ETH balances in the protocol, equals to the total supply of stETH.
               */
              function getTotalPooledEther() external view returns (uint256) {
                  return _getTotalPooledEther();
              }
              /**
               * @return the amount of tokens owned by the `_account`.
               *
               * @dev Balances are dynamic and equal the `_account`'s share in the amount of the
               * total Ether controlled by the protocol. See `sharesOf`.
               */
              function balanceOf(address _account) external view returns (uint256) {
                  return getPooledEthByShares(_sharesOf(_account));
              }
              /**
               * @notice Moves `_amount` tokens from the caller's account to the `_recipient` account.
               *
               * @return a boolean value indicating whether the operation succeeded.
               * Emits a `Transfer` event.
               * Emits a `TransferShares` event.
               *
               * Requirements:
               *
               * - `_recipient` cannot be the zero address.
               * - the caller must have a balance of at least `_amount`.
               * - the contract must not be paused.
               *
               * @dev The `_amount` argument is the amount of tokens, not shares.
               */
              function transfer(address _recipient, uint256 _amount) external returns (bool) {
                  _transfer(msg.sender, _recipient, _amount);
                  return true;
              }
              /**
               * @return the remaining number of tokens that `_spender` is allowed to spend
               * on behalf of `_owner` through `transferFrom`. This is zero by default.
               *
               * @dev This value changes when `approve` or `transferFrom` is called.
               */
              function allowance(address _owner, address _spender) external view returns (uint256) {
                  return allowances[_owner][_spender];
              }
              /**
               * @notice Sets `_amount` as the allowance of `_spender` over the caller's tokens.
               *
               * @return a boolean value indicating whether the operation succeeded.
               * Emits an `Approval` event.
               *
               * Requirements:
               *
               * - `_spender` cannot be the zero address.
               *
               * @dev The `_amount` argument is the amount of tokens, not shares.
               */
              function approve(address _spender, uint256 _amount) external returns (bool) {
                  _approve(msg.sender, _spender, _amount);
                  return true;
              }
              /**
               * @notice Moves `_amount` tokens from `_sender` to `_recipient` using the
               * allowance mechanism. `_amount` is then deducted from the caller's
               * allowance.
               *
               * @return a boolean value indicating whether the operation succeeded.
               *
               * Emits a `Transfer` event.
               * Emits a `TransferShares` event.
               * Emits an `Approval` event indicating the updated allowance.
               *
               * Requirements:
               *
               * - `_sender` and `_recipient` cannot be the zero addresses.
               * - `_sender` must have a balance of at least `_amount`.
               * - the caller must have allowance for `_sender`'s tokens of at least `_amount`.
               * - the contract must not be paused.
               *
               * @dev The `_amount` argument is the amount of tokens, not shares.
               */
              function transferFrom(address _sender, address _recipient, uint256 _amount) external returns (bool) {
                  _spendAllowance(_sender, msg.sender, _amount);
                  _transfer(_sender, _recipient, _amount);
                  return true;
              }
              /**
               * @notice Atomically increases the allowance granted to `_spender` by the caller by `_addedValue`.
               *
               * This is an alternative to `approve` that can be used as a mitigation for
               * problems described in:
               * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/b709eae01d1da91902d06ace340df6b324e6f049/contracts/token/ERC20/IERC20.sol#L57
               * Emits an `Approval` event indicating the updated allowance.
               *
               * Requirements:
               *
               * - `_spender` cannot be the the zero address.
               */
              function increaseAllowance(address _spender, uint256 _addedValue) external returns (bool) {
                  _approve(msg.sender, _spender, allowances[msg.sender][_spender].add(_addedValue));
                  return true;
              }
              /**
               * @notice Atomically decreases the allowance granted to `_spender` by the caller by `_subtractedValue`.
               *
               * This is an alternative to `approve` that can be used as a mitigation for
               * problems described in:
               * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/b709eae01d1da91902d06ace340df6b324e6f049/contracts/token/ERC20/IERC20.sol#L57
               * Emits an `Approval` event indicating the updated allowance.
               *
               * Requirements:
               *
               * - `_spender` cannot be the zero address.
               * - `_spender` must have allowance for the caller of at least `_subtractedValue`.
               */
              function decreaseAllowance(address _spender, uint256 _subtractedValue) external returns (bool) {
                  uint256 currentAllowance = allowances[msg.sender][_spender];
                  require(currentAllowance >= _subtractedValue, "ALLOWANCE_BELOW_ZERO");
                  _approve(msg.sender, _spender, currentAllowance.sub(_subtractedValue));
                  return true;
              }
              /**
               * @return the total amount of shares in existence.
               *
               * @dev The sum of all accounts' shares can be an arbitrary number, therefore
               * it is necessary to store it in order to calculate each account's relative share.
               */
              function getTotalShares() external view returns (uint256) {
                  return _getTotalShares();
              }
              /**
               * @return the amount of shares owned by `_account`.
               */
              function sharesOf(address _account) external view returns (uint256) {
                  return _sharesOf(_account);
              }
              /**
               * @return the amount of shares that corresponds to `_ethAmount` protocol-controlled Ether.
               */
              function getSharesByPooledEth(uint256 _ethAmount) public view returns (uint256) {
                  return _ethAmount
                      .mul(_getTotalShares())
                      .div(_getTotalPooledEther());
              }
              /**
               * @return the amount of Ether that corresponds to `_sharesAmount` token shares.
               */
              function getPooledEthByShares(uint256 _sharesAmount) public view returns (uint256) {
                  return _sharesAmount
                      .mul(_getTotalPooledEther())
                      .div(_getTotalShares());
              }
              /**
               * @notice Moves `_sharesAmount` token shares from the caller's account to the `_recipient` account.
               *
               * @return amount of transferred tokens.
               * Emits a `TransferShares` event.
               * Emits a `Transfer` event.
               *
               * Requirements:
               *
               * - `_recipient` cannot be the zero address.
               * - the caller must have at least `_sharesAmount` shares.
               * - the contract must not be paused.
               *
               * @dev The `_sharesAmount` argument is the amount of shares, not tokens.
               */
              function transferShares(address _recipient, uint256 _sharesAmount) external returns (uint256) {
                  _transferShares(msg.sender, _recipient, _sharesAmount);
                  uint256 tokensAmount = getPooledEthByShares(_sharesAmount);
                  _emitTransferEvents(msg.sender, _recipient, tokensAmount, _sharesAmount);
                  return tokensAmount;
              }
              /**
               * @notice Moves `_sharesAmount` token shares from the `_sender` account to the `_recipient` account.
               *
               * @return amount of transferred tokens.
               * Emits a `TransferShares` event.
               * Emits a `Transfer` event.
               *
               * Requirements:
               *
               * - `_sender` and `_recipient` cannot be the zero addresses.
               * - `_sender` must have at least `_sharesAmount` shares.
               * - the caller must have allowance for `_sender`'s tokens of at least `getPooledEthByShares(_sharesAmount)`.
               * - the contract must not be paused.
               *
               * @dev The `_sharesAmount` argument is the amount of shares, not tokens.
               */
              function transferSharesFrom(
                  address _sender, address _recipient, uint256 _sharesAmount
              ) external returns (uint256) {
                  uint256 tokensAmount = getPooledEthByShares(_sharesAmount);
                  _spendAllowance(_sender, msg.sender, tokensAmount);
                  _transferShares(_sender, _recipient, _sharesAmount);
                  _emitTransferEvents(_sender, _recipient, tokensAmount, _sharesAmount);
                  return tokensAmount;
              }
              /**
               * @return the total amount (in wei) of Ether controlled by the protocol.
               * @dev This is used for calculating tokens from shares and vice versa.
               * @dev This function is required to be implemented in a derived contract.
               */
              function _getTotalPooledEther() internal view returns (uint256);
              /**
               * @notice Moves `_amount` tokens from `_sender` to `_recipient`.
               * Emits a `Transfer` event.
               * Emits a `TransferShares` event.
               */
              function _transfer(address _sender, address _recipient, uint256 _amount) internal {
                  uint256 _sharesToTransfer = getSharesByPooledEth(_amount);
                  _transferShares(_sender, _recipient, _sharesToTransfer);
                  _emitTransferEvents(_sender, _recipient, _amount, _sharesToTransfer);
              }
              /**
               * @notice Sets `_amount` as the allowance of `_spender` over the `_owner` s tokens.
               *
               * Emits an `Approval` event.
               *
               * NB: the method can be invoked even if the protocol paused.
               *
               * Requirements:
               *
               * - `_owner` cannot be the zero address.
               * - `_spender` cannot be the zero address.
               */
              function _approve(address _owner, address _spender, uint256 _amount) internal {
                  require(_owner != address(0), "APPROVE_FROM_ZERO_ADDR");
                  require(_spender != address(0), "APPROVE_TO_ZERO_ADDR");
                  allowances[_owner][_spender] = _amount;
                  emit Approval(_owner, _spender, _amount);
              }
              /**
               * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
               *
               * Does not update the allowance amount in case of infinite allowance.
               * Revert if not enough allowance is available.
               *
               * Might emit an {Approval} event.
               */
              function _spendAllowance(address _owner, address _spender, uint256 _amount) internal {
                  uint256 currentAllowance = allowances[_owner][_spender];
                  if (currentAllowance != INFINITE_ALLOWANCE) {
                      require(currentAllowance >= _amount, "ALLOWANCE_EXCEEDED");
                      _approve(_owner, _spender, currentAllowance - _amount);
                  }
              }
              /**
               * @return the total amount of shares in existence.
               */
              function _getTotalShares() internal view returns (uint256) {
                  return TOTAL_SHARES_POSITION.getStorageUint256();
              }
              /**
               * @return the amount of shares owned by `_account`.
               */
              function _sharesOf(address _account) internal view returns (uint256) {
                  return shares[_account];
              }
              /**
               * @notice Moves `_sharesAmount` shares from `_sender` to `_recipient`.
               *
               * Requirements:
               *
               * - `_sender` cannot be the zero address.
               * - `_recipient` cannot be the zero address or the `stETH` token contract itself
               * - `_sender` must hold at least `_sharesAmount` shares.
               * - the contract must not be paused.
               */
              function _transferShares(address _sender, address _recipient, uint256 _sharesAmount) internal {
                  require(_sender != address(0), "TRANSFER_FROM_ZERO_ADDR");
                  require(_recipient != address(0), "TRANSFER_TO_ZERO_ADDR");
                  require(_recipient != address(this), "TRANSFER_TO_STETH_CONTRACT");
                  _whenNotStopped();
                  uint256 currentSenderShares = shares[_sender];
                  require(_sharesAmount <= currentSenderShares, "BALANCE_EXCEEDED");
                  shares[_sender] = currentSenderShares.sub(_sharesAmount);
                  shares[_recipient] = shares[_recipient].add(_sharesAmount);
              }
              /**
               * @notice Creates `_sharesAmount` shares and assigns them to `_recipient`, increasing the total amount of shares.
               * @dev This doesn't increase the token total supply.
               *
               * NB: The method doesn't check protocol pause relying on the external enforcement.
               *
               * Requirements:
               *
               * - `_recipient` cannot be the zero address.
               * - the contract must not be paused.
               */
              function _mintShares(address _recipient, uint256 _sharesAmount) internal returns (uint256 newTotalShares) {
                  require(_recipient != address(0), "MINT_TO_ZERO_ADDR");
                  newTotalShares = _getTotalShares().add(_sharesAmount);
                  TOTAL_SHARES_POSITION.setStorageUint256(newTotalShares);
                  shares[_recipient] = shares[_recipient].add(_sharesAmount);
                  // Notice: we're not emitting a Transfer event from the zero address here since shares mint
                  // works by taking the amount of tokens corresponding to the minted shares from all other
                  // token holders, proportionally to their share. The total supply of the token doesn't change
                  // as the result. This is equivalent to performing a send from each other token holder's
                  // address to `address`, but we cannot reflect this as it would require sending an unbounded
                  // number of events.
              }
              /**
               * @notice Destroys `_sharesAmount` shares from `_account`'s holdings, decreasing the total amount of shares.
               * @dev This doesn't decrease the token total supply.
               *
               * Requirements:
               *
               * - `_account` cannot be the zero address.
               * - `_account` must hold at least `_sharesAmount` shares.
               * - the contract must not be paused.
               */
              function _burnShares(address _account, uint256 _sharesAmount) internal returns (uint256 newTotalShares) {
                  require(_account != address(0), "BURN_FROM_ZERO_ADDR");
                  uint256 accountShares = shares[_account];
                  require(_sharesAmount <= accountShares, "BALANCE_EXCEEDED");
                  uint256 preRebaseTokenAmount = getPooledEthByShares(_sharesAmount);
                  newTotalShares = _getTotalShares().sub(_sharesAmount);
                  TOTAL_SHARES_POSITION.setStorageUint256(newTotalShares);
                  shares[_account] = accountShares.sub(_sharesAmount);
                  uint256 postRebaseTokenAmount = getPooledEthByShares(_sharesAmount);
                  emit SharesBurnt(_account, preRebaseTokenAmount, postRebaseTokenAmount, _sharesAmount);
                  // Notice: we're not emitting a Transfer event to the zero address here since shares burn
                  // works by redistributing the amount of tokens corresponding to the burned shares between
                  // all other token holders. The total supply of the token doesn't change as the result.
                  // This is equivalent to performing a send from `address` to each other token holder address,
                  // but we cannot reflect this as it would require sending an unbounded number of events.
                  // We're emitting `SharesBurnt` event to provide an explicit rebase log record nonetheless.
              }
              /**
               * @dev Emits {Transfer} and {TransferShares} events
               */
              function _emitTransferEvents(address _from, address _to, uint _tokenAmount, uint256 _sharesAmount) internal {
                  emit Transfer(_from, _to, _tokenAmount);
                  emit TransferShares(_from, _to, _sharesAmount);
              }
              /**
               * @dev Emits {Transfer} and {TransferShares} events where `from` is 0 address. Indicates mint events.
               */
              function _emitTransferAfterMintingShares(address _to, uint256 _sharesAmount) internal {
                  _emitTransferEvents(address(0), _to, getPooledEthByShares(_sharesAmount), _sharesAmount);
              }
              /**
               * @dev Mints shares to INITIAL_TOKEN_HOLDER
               */
              function _mintInitialShares(uint256 _sharesAmount) internal {
                  _mintShares(INITIAL_TOKEN_HOLDER, _sharesAmount);
                  _emitTransferAfterMintingShares(INITIAL_TOKEN_HOLDER, _sharesAmount);
              }
          }
          // SPDX-FileCopyrightText: 2023 OpenZeppelin, Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          /* See contracts/COMPILERS.md */
          pragma solidity 0.4.24;
          import {UnstructuredStorage} from "@aragon/os/contracts/common/UnstructuredStorage.sol";
          import {SignatureUtils} from "../common/lib/SignatureUtils.sol";
          import {IEIP712StETH} from "../common/interfaces/IEIP712StETH.sol";
          import {StETH} from "./StETH.sol";
          /**
           * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
           * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
           *
           * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
           * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
           * need to send a transaction, and thus is not required to hold Ether at all.
           */
          interface IERC2612 {
              /**
               * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
               * given ``owner``'s signed approval.
               * Emits an {Approval} event.
               *
               * Requirements:
               *
               * - `spender` cannot be the zero address.
               * - `deadline` must be a timestamp in the future.
               * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
               * over the EIP712-formatted function arguments.
               * - the signature must use ``owner``'s current nonce (see {nonces}).
               */
              function permit(
                  address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s
              ) external;
              /**
               * @dev Returns the current nonce for `owner`. This value must be
               * included whenever a signature is generated for {permit}.
               *
               * Every successful call to {permit} increases ``owner``'s nonce by one. This
               * prevents a signature from being used multiple times.
               */
              function nonces(address owner) external view returns (uint256);
              /**
               * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
               */
              // solhint-disable-next-line func-name-mixedcase
              function DOMAIN_SEPARATOR() external view returns (bytes32);
          }
          contract StETHPermit is IERC2612, StETH {
              using UnstructuredStorage for bytes32;
              /**
               * @dev Service event for initialization
               */
              event EIP712StETHInitialized(address eip712StETH);
              /**
               * @dev Nonces for ERC-2612 (Permit)
               */
              mapping(address => uint256) internal noncesByAddress;
              /**
               * @dev Storage position used for the EIP712 message utils contract
               *
               * keccak256("lido.StETHPermit.eip712StETH")
               */
              bytes32 internal constant EIP712_STETH_POSITION =
                  0x42b2d95e1ce15ce63bf9a8d9f6312cf44b23415c977ffa3b884333422af8941c;
              /**
               * @dev Typehash constant for ERC-2612 (Permit)
               *
               * keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
               */
              bytes32 internal constant PERMIT_TYPEHASH =
                  0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
              /**
               * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
               * given ``owner``'s signed approval.
               * Emits an {Approval} event.
               *
               * Requirements:
               *
               * - `spender` cannot be the zero address.
               * - `deadline` must be a timestamp in the future.
               * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
               * over the EIP712-formatted function arguments.
               * - the signature must use ``owner``'s current nonce (see {nonces}).
               */
              function permit(
                  address _owner, address _spender, uint256 _value, uint256 _deadline, uint8 _v, bytes32 _r, bytes32 _s
              ) external {
                  require(block.timestamp <= _deadline, "DEADLINE_EXPIRED");
                  bytes32 structHash = keccak256(
                      abi.encode(PERMIT_TYPEHASH, _owner, _spender, _value, _useNonce(_owner), _deadline)
                  );
                  bytes32 hash = IEIP712StETH(getEIP712StETH()).hashTypedDataV4(address(this), structHash);
                  require(SignatureUtils.isValidSignature(_owner, hash, _v, _r, _s), "INVALID_SIGNATURE");
                  _approve(_owner, _spender, _value);
              }
              /**
               * @dev Returns the current nonce for `owner`. This value must be
               * included whenever a signature is generated for {permit}.
               *
               * Every successful call to {permit} increases ``owner``'s nonce by one. This
               * prevents a signature from being used multiple times.
               */
              function nonces(address owner) external view returns (uint256) {
                  return noncesByAddress[owner];
              }
              /**
               * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
               */
              // solhint-disable-next-line func-name-mixedcase
              function DOMAIN_SEPARATOR() external view returns (bytes32) {
                  return IEIP712StETH(getEIP712StETH()).domainSeparatorV4(address(this));
              }
              /**
               * @dev returns the fields and values that describe the domain separator used by this contract for EIP-712
               * signature.
               *
               * NB: compairing to the full-fledged ERC-5267 version:
               * - `salt` and `extensions` are unused
               * - `flags` is hex"0f" or 01111b
               *
               * @dev using shortened returns to reduce a bytecode size
               */
              function eip712Domain() external view returns (
                  string memory name,
                  string memory version,
                  uint256 chainId,
                  address verifyingContract
              ) {
                  return IEIP712StETH(getEIP712StETH()).eip712Domain(address(this));
              }
              /**
               * @dev "Consume a nonce": return the current value and increment.
               */
              function _useNonce(address _owner) internal returns (uint256 current) {
                  current = noncesByAddress[_owner];
                  noncesByAddress[_owner] = current.add(1);
              }
              /**
               * @dev Initialize EIP712 message utils contract for stETH
               */
              function _initializeEIP712StETH(address _eip712StETH) internal {
                  require(_eip712StETH != address(0), "ZERO_EIP712STETH");
                  require(getEIP712StETH() == address(0), "EIP712STETH_ALREADY_SET");
                  EIP712_STETH_POSITION.setStorageAddress(_eip712StETH);
                  emit EIP712StETHInitialized(_eip712StETH);
              }
              /**
               * @dev Get EIP712 message utils contract
               */
              function getEIP712StETH() public view returns (address) {
                  return EIP712_STETH_POSITION.getStorageAddress();
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          pragma solidity 0.4.24;
          import "@aragon/os/contracts/common/UnstructuredStorage.sol";
          contract Pausable {
              using UnstructuredStorage for bytes32;
              event Stopped();
              event Resumed();
              // keccak256("lido.Pausable.activeFlag")
              bytes32 internal constant ACTIVE_FLAG_POSITION =
                  0x644132c4ddd5bb6f0655d5fe2870dcec7870e6be4758890f366b83441f9fdece;
              function _whenNotStopped() internal view {
                  require(ACTIVE_FLAG_POSITION.getStorageBool(), "CONTRACT_IS_STOPPED");
              }
              function _whenStopped() internal view {
                  require(!ACTIVE_FLAG_POSITION.getStorageBool(), "CONTRACT_IS_ACTIVE");
              }
              function isStopped() public view returns (bool) {
                  return !ACTIVE_FLAG_POSITION.getStorageBool();
              }
              function _stop() internal {
                  _whenNotStopped();
                  ACTIVE_FLAG_POSITION.setStorageBool(false);
                  emit Stopped();
              }
              function _resume() internal {
                  _whenStopped();
                  ACTIVE_FLAG_POSITION.setStorageBool(true);
                  emit Resumed();
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          pragma solidity 0.4.24;
          import "@aragon/os/contracts/common/UnstructuredStorage.sol";
          /**
           * @title Adapted code of /contracts/0.8.9/utils/Versioned.sol
           *
           * This contract contains only core part of original Versioned.sol
           * to reduce contract size
           */
          contract Versioned {
              using UnstructuredStorage for bytes32;
              event ContractVersionSet(uint256 version);
              /// @dev Storage slot: uint256 version
              /// Version of the initialized contract storage.
              /// The version stored in CONTRACT_VERSION_POSITION equals to:
              /// - 0 right after the deployment, before an initializer is invoked (and only at that moment);
              /// - N after calling initialize(), where N is the initially deployed contract version;
              /// - N after upgrading contract by calling finalizeUpgrade_vN().
              bytes32 internal constant CONTRACT_VERSION_POSITION =
                  0x4dd0f6662ba1d6b081f08b350f5e9a6a7b15cf586926ba66f753594928fa64a6; // keccak256("lido.Versioned.contractVersion");
              uint256 internal constant PETRIFIED_VERSION_MARK = uint256(-1);
              constructor() public {
                  // lock version in the implementation's storage to prevent initialization
                  CONTRACT_VERSION_POSITION.setStorageUint256(PETRIFIED_VERSION_MARK);
              }
              /// @notice Returns the current contract version.
              function getContractVersion() public view returns (uint256) {
                  return CONTRACT_VERSION_POSITION.getStorageUint256();
              }
              function _checkContractVersion(uint256 version) internal view {
                  require(version == getContractVersion(), "UNEXPECTED_CONTRACT_VERSION");
              }
              function _setContractVersion(uint256 version) internal {
                  CONTRACT_VERSION_POSITION.setStorageUint256(version);
                  emit ContractVersionSet(version);
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          // See contracts/COMPILERS.md
          // solhint-disable-next-line
          pragma solidity >=0.4.24 <0.9.0;
          interface IBurner {
              /**
               * Commit cover/non-cover burning requests and logs cover/non-cover shares amount just burnt.
               *
               * NB: The real burn enactment to be invoked after the call (via internal Lido._burnShares())
               */
              function commitSharesToBurn(uint256 _stETHSharesToBurn) external;
              /**
               * Request burn shares
               */
              function requestBurnShares(address _from, uint256 _sharesAmount) external;
              /**
                * Returns the current amount of shares locked on the contract to be burnt.
                */
              function getSharesRequestedToBurn() external view returns (uint256 coverShares, uint256 nonCoverShares);
              /**
                * Returns the total cover shares ever burnt.
                */
              function getCoverSharesBurnt() external view returns (uint256);
              /**
                * Returns the total non-cover shares ever burnt.
                */
              function getNonCoverSharesBurnt() external view returns (uint256);
          }
          // SPDX-FileCopyrightText: 2023 OpenZeppelin, Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          // See contracts/COMPILERS.md
          // solhint-disable-next-line
          pragma solidity >=0.4.24 <0.9.0;
          /**
           * @dev Helper interface of EIP712 StETH-dedicated helper.
           *
           * Has an access to the CHAIN_ID opcode and relies on immutables internally
           * Both are unavailable for Solidity 0.4.24.
           */
          interface IEIP712StETH {
              /**
               * @dev Returns the domain separator for the current chain.
               */
              function domainSeparatorV4(address _stETH) external view returns (bytes32);
              /**
               * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this
               * function returns the hash of the fully encoded EIP712 message for this domain.
               *
               * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:
               *
               * ```solidity
               * bytes32 digest = hashTypedDataV4(keccak256(abi.encode(
               *     keccak256("Mail(address to,string contents)"),
               *     mailTo,
               *     keccak256(bytes(mailContents))
               * )));
               * address signer = ECDSA.recover(digest, signature);
               * ```
               */
              function hashTypedDataV4(address _stETH, bytes32 _structHash) external view returns (bytes32);
              /**
               * @dev returns the fields and values that describe the domain separator
               * used by stETH for EIP-712 signature.
               */
              function eip712Domain(address _stETH) external view returns (
                  string memory name,
                  string memory version,
                  uint256 chainId,
                  address verifyingContract
              );
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: GPL-3.0
          // See contracts/COMPILERS.md
          // solhint-disable-next-line
          pragma solidity >=0.4.24 <0.9.0;
          interface ILidoLocator {
              function accountingOracle() external view returns(address);
              function depositSecurityModule() external view returns(address);
              function elRewardsVault() external view returns(address);
              function legacyOracle() external view returns(address);
              function lido() external view returns(address);
              function oracleReportSanityChecker() external view returns(address);
              function burner() external view returns(address);
              function stakingRouter() external view returns(address);
              function treasury() external view returns(address);
              function validatorsExitBusOracle() external view returns(address);
              function withdrawalQueue() external view returns(address);
              function withdrawalVault() external view returns(address);
              function postTokenRebaseReceiver() external view returns(address);
              function oracleDaemonConfig() external view returns(address);
              function coreComponents() external view returns(
                  address elRewardsVault,
                  address oracleReportSanityChecker,
                  address stakingRouter,
                  address treasury,
                  address withdrawalQueue,
                  address withdrawalVault
              );
              function oracleReportComponentsForLido() external view returns(
                  address accountingOracle,
                  address elRewardsVault,
                  address oracleReportSanityChecker,
                  address burner,
                  address withdrawalQueue,
                  address withdrawalVault,
                  address postTokenRebaseReceiver
              );
          }
          // SPDX-License-Identifier: MIT
          // Extracted from:
          // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/cryptography/ECDSA.sol#L53
          // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/541e821/contracts/utils/cryptography/ECDSA.sol#L112
          /* See contracts/COMPILERS.md */
          // solhint-disable-next-line
          pragma solidity >=0.4.24 <0.9.0;
          library ECDSA {
              /**
               * @dev Returns the address that signed a hashed message (`hash`).
               * This address can then be used for verification purposes.
               * Receives the `v`, `r` and `s` signature fields separately.
               *
               * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
               * this function rejects them by requiring the `s` value to be in the lower
               * half order, and the `v` value to be either 27 or 28.
               *
               * IMPORTANT: `hash` _must_ be the result of a hash operation for the
               * verification to be secure: it is possible to craft signatures that
               * recover to arbitrary addresses for non-hashed data.
               */
              function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address)
              {
                  // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                  // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                  // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                  // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                  //
                  // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                  // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                  // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                  // these malleable signatures as well.
                  require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, "ECDSA: invalid signature 's' value");
                  // If the signature is valid (and not malleable), return the signer address
                  address signer = ecrecover(hash, v, r, s);
                  require(signer != address(0), "ECDSA: invalid signature");
                  return signer;
              }
              /**
               * @dev Overload of `recover` that receives the `r` and `vs` short-signature fields separately.
               * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
               */
              function recover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address) {
                  bytes32 s;
                  uint8 v;
                  assembly {
                      s := and(vs, 0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff)
                      v := add(shr(255, vs), 27)
                  }
                  return recover(hash, v, r, s);
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: MIT
          // Copied from: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/0457042d93d9dfd760dbaa06a4d2f1216fdbe297/contracts/utils/math/Math.sol
          // See contracts/COMPILERS.md
          // solhint-disable-next-line
          pragma solidity >=0.4.24 <0.9.0;
          library Math256 {
              /// @dev Returns the largest of two numbers.
              function max(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a > b ? a : b;
              }
              /// @dev Returns the smallest of two numbers.
              function min(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a < b ? a : b;
              }
              /// @dev Returns the largest of two numbers.
              function max(int256 a, int256 b) internal pure returns (int256) {
                  return a > b ? a : b;
              }
              /// @dev Returns the smallest of two numbers.
              function min(int256 a, int256 b) internal pure returns (int256) {
                  return a < b ? a : b;
              }
              /// @dev Returns the ceiling of the division of two numbers.
              ///
              /// This differs from standard division with `/` in that it rounds up instead
              /// of rounding down.
              function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
                  // (a + b - 1) / b can overflow on addition, so we distribute.
                  return a == 0 ? 0 : (a - 1) / b + 1;
              }
              /// @dev Returns absolute difference of two numbers.
              function absDiff(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a > b ? a - b : b - a;
              }
          }
          // SPDX-FileCopyrightText: 2023 Lido <[email protected]>
          // SPDX-License-Identifier: MIT
          /* See contracts/COMPILERS.md */
          // solhint-disable-next-line lido/fixed-compiler-version
          pragma solidity >=0.4.24 <0.9.0;
          import {ECDSA} from "./ECDSA.sol";
          library SignatureUtils {
              /**
               * @dev The selector of the ERC1271's `isValidSignature(bytes32 hash, bytes signature)` function,
               * serving at the same time as the magic value that the function should return upon success.
               *
               * See https://eips.ethereum.org/EIPS/eip-1271.
               *
               * bytes4(keccak256("isValidSignature(bytes32,bytes)")
               */
              bytes4 internal constant ERC1271_IS_VALID_SIGNATURE_SELECTOR = 0x1626ba7e;
              /**
               * @dev Checks signature validity.
               *
               * If the signer address doesn't contain any code, assumes that the address is externally owned
               * and the signature is a ECDSA signature generated using its private key. Otherwise, issues a
               * static call to the signer address to check the signature validity using the ERC-1271 standard.
               */
              function isValidSignature(
                  address signer,
                  bytes32 msgHash,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) internal view returns (bool) {
                  if (_hasCode(signer)) {
                      bytes memory sig = abi.encodePacked(r, s, v);
                      // Solidity <0.5 generates a regular CALL instruction even if the function being called
                      // is marked as `view`, and the only way to perform a STATICCALL is to use assembly
                      bytes memory data = abi.encodeWithSelector(ERC1271_IS_VALID_SIGNATURE_SELECTOR, msgHash, sig);
                      bytes32 retval;
                      /// @solidity memory-safe-assembly
                      assembly {
                          // allocate memory for storing the return value
                          let outDataOffset := mload(0x40)
                          mstore(0x40, add(outDataOffset, 32))
                          // issue a static call and load the result if the call succeeded
                          let success := staticcall(gas(), signer, add(data, 32), mload(data), outDataOffset, 32)
                          if and(eq(success, 1), eq(returndatasize(), 32)) {
                              retval := mload(outDataOffset)
                          }
                      }
                      return retval == bytes32(ERC1271_IS_VALID_SIGNATURE_SELECTOR);
                  } else {
                      return ECDSA.recover(msgHash, v, r, s) == signer;
                  }
              }
              function _hasCode(address addr) internal view returns (bool) {
                  uint256 size;
                  /// @solidity memory-safe-assembly
                  assembly { size := extcodesize(addr) }
                  return size > 0;
              }
          }
          pragma solidity ^0.4.24;
          /**
           * @title ERC20 interface
           * @dev see https://github.com/ethereum/EIPs/issues/20
           */
          interface IERC20 {
            function totalSupply() external view returns (uint256);
            function balanceOf(address who) external view returns (uint256);
            function allowance(address owner, address spender)
              external view returns (uint256);
            function transfer(address to, uint256 value) external returns (bool);
            function approve(address spender, uint256 value)
              external returns (bool);
            function transferFrom(address from, address to, uint256 value)
              external returns (bool);
            event Transfer(
              address indexed from,
              address indexed to,
              uint256 value
            );
            event Approval(
              address indexed owner,
              address indexed spender,
              uint256 value
            );
          }