ETH Price: $2,517.40 (-0.92%)
Gas: 0.44 Gwei

Transaction Decoder

Block:
20863159 at Sep-30-2024 11:26:11 AM +UTC
Transaction Fee:
0.00223935875841852 ETH $5.64
Gas Used:
292,086 Gas / 7.66677882 Gwei

Account State Difference:

  Address   Before After State Difference Code
(Titan Builder)
14.590422821827899588 Eth14.590697645545299588 Eth0.0002748237174
0xABeD1aF9...99c6ab5E3
0.005282594233162022 Eth
Nonce: 408
0.003043235474743502 Eth
Nonce: 409
0.00223935875841852

Execution Trace

TransparentUpgradeableProxy.9e2c8a5b( )
  • zStakeCorePool.unstake( _depositId=4, _amount=242823651624809844219 )
    • TransparentUpgradeableProxy.STATICCALL( )
      • zStakePoolFactory.DELEGATECALL( )
      • TransparentUpgradeableProxy.STATICCALL( )
        • zStakePoolFactory.DELEGATECALL( )
          File 1 of 4: TransparentUpgradeableProxy
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
          import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
          import "@openzeppelin/contracts/proxy/transparent/ProxyAdmin.sol";
          // Kept for backwards compatibility with older versions of Hardhat and Truffle plugins.
          contract AdminUpgradeabilityProxy is TransparentUpgradeableProxy {
              constructor(address logic, address admin, bytes memory data) payable TransparentUpgradeableProxy(logic, admin, data) {}
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../Proxy.sol";
          import "./ERC1967Upgrade.sol";
          /**
           * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
           * implementation address that can be changed. This address is stored in storage in the location specified by
           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
           * implementation behind the proxy.
           */
          contract ERC1967Proxy is Proxy, ERC1967Upgrade {
              /**
               * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
               *
               * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
               * function call, and allows initializating the storage of the proxy like a Solidity constructor.
               */
              constructor(address _logic, bytes memory _data) payable {
                  assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                  _upgradeToAndCall(_logic, _data, false);
              }
              /**
               * @dev Returns the current implementation address.
               */
              function _implementation() internal view virtual override returns (address impl) {
                  return ERC1967Upgrade._getImplementation();
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../ERC1967/ERC1967Proxy.sol";
          /**
           * @dev This contract implements a proxy that is upgradeable by an admin.
           *
           * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
           * clashing], which can potentially be used in an attack, this contract uses the
           * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
           * things that go hand in hand:
           *
           * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
           * that call matches one of the admin functions exposed by the proxy itself.
           * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
           * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
           * "admin cannot fallback to proxy target".
           *
           * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
           * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
           * to sudden errors when trying to call a function from the proxy implementation.
           *
           * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
           * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
           */
          contract TransparentUpgradeableProxy is ERC1967Proxy {
              /**
               * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
               * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
               */
              constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
                  assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                  _changeAdmin(admin_);
              }
              /**
               * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
               */
              modifier ifAdmin() {
                  if (msg.sender == _getAdmin()) {
                      _;
                  } else {
                      _fallback();
                  }
              }
              /**
               * @dev Returns the current admin.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
               *
               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
               * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
               */
              function admin() external ifAdmin returns (address admin_) {
                  admin_ = _getAdmin();
              }
              /**
               * @dev Returns the current implementation.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
               *
               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
               * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
               */
              function implementation() external ifAdmin returns (address implementation_) {
                  implementation_ = _implementation();
              }
              /**
               * @dev Changes the admin of the proxy.
               *
               * Emits an {AdminChanged} event.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
               */
              function changeAdmin(address newAdmin) external virtual ifAdmin {
                  _changeAdmin(newAdmin);
              }
              /**
               * @dev Upgrade the implementation of the proxy.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
               */
              function upgradeTo(address newImplementation) external ifAdmin {
                  _upgradeToAndCall(newImplementation, bytes(""), false);
              }
              /**
               * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
               * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
               * proxied contract.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
               */
              function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                  _upgradeToAndCall(newImplementation, data, true);
              }
              /**
               * @dev Returns the current admin.
               */
              function _admin() internal view virtual returns (address) {
                  return _getAdmin();
              }
              /**
               * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
               */
              function _beforeFallback() internal virtual override {
                  require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                  super._beforeFallback();
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "./TransparentUpgradeableProxy.sol";
          import "../../access/Ownable.sol";
          /**
           * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
           * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
           */
          contract ProxyAdmin is Ownable {
              /**
               * @dev Returns the current implementation of `proxy`.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
                  // We need to manually run the static call since the getter cannot be flagged as view
                  // bytes4(keccak256("implementation()")) == 0x5c60da1b
                  (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
                  require(success);
                  return abi.decode(returndata, (address));
              }
              /**
               * @dev Returns the current admin of `proxy`.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
                  // We need to manually run the static call since the getter cannot be flagged as view
                  // bytes4(keccak256("admin()")) == 0xf851a440
                  (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
                  require(success);
                  return abi.decode(returndata, (address));
              }
              /**
               * @dev Changes the admin of `proxy` to `newAdmin`.
               *
               * Requirements:
               *
               * - This contract must be the current admin of `proxy`.
               */
              function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
                  proxy.changeAdmin(newAdmin);
              }
              /**
               * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
                  proxy.upgradeTo(implementation);
              }
              /**
               * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
               * {TransparentUpgradeableProxy-upgradeToAndCall}.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
                  proxy.upgradeToAndCall{value: msg.value}(implementation, data);
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
           * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
           * be specified by overriding the virtual {_implementation} function.
           *
           * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
           * different contract through the {_delegate} function.
           *
           * The success and return data of the delegated call will be returned back to the caller of the proxy.
           */
          abstract contract Proxy {
              /**
               * @dev Delegates the current call to `implementation`.
               *
               * This function does not return to its internall call site, it will return directly to the external caller.
               */
              function _delegate(address implementation) internal virtual {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // Copy msg.data. We take full control of memory in this inline assembly
                      // block because it will not return to Solidity code. We overwrite the
                      // Solidity scratch pad at memory position 0.
                      calldatacopy(0, 0, calldatasize())
                      // Call the implementation.
                      // out and outsize are 0 because we don't know the size yet.
                      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                      // Copy the returned data.
                      returndatacopy(0, 0, returndatasize())
                      switch result
                      // delegatecall returns 0 on error.
                      case 0 { revert(0, returndatasize()) }
                      default { return(0, returndatasize()) }
                  }
              }
              /**
               * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
               * and {_fallback} should delegate.
               */
              function _implementation() internal view virtual returns (address);
              /**
               * @dev Delegates the current call to the address returned by `_implementation()`.
               *
               * This function does not return to its internall call site, it will return directly to the external caller.
               */
              function _fallback() internal virtual {
                  _beforeFallback();
                  _delegate(_implementation());
              }
              /**
               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
               * function in the contract matches the call data.
               */
              fallback () external payable virtual {
                  _fallback();
              }
              /**
               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
               * is empty.
               */
              receive () external payable virtual {
                  _fallback();
              }
              /**
               * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
               * call, or as part of the Solidity `fallback` or `receive` functions.
               *
               * If overriden should call `super._beforeFallback()`.
               */
              function _beforeFallback() internal virtual {
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.2;
          import "../beacon/IBeacon.sol";
          import "../../utils/Address.sol";
          import "../../utils/StorageSlot.sol";
          /**
           * @dev This abstract contract provides getters and event emitting update functions for
           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
           *
           * _Available since v4.1._
           *
           * @custom:oz-upgrades-unsafe-allow delegatecall
           */
          abstract contract ERC1967Upgrade {
              // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
              bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
              /**
               * @dev Storage slot with the address of the current implementation.
               * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
               * validated in the constructor.
               */
              bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
              /**
               * @dev Emitted when the implementation is upgraded.
               */
              event Upgraded(address indexed implementation);
              /**
               * @dev Returns the current implementation address.
               */
              function _getImplementation() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
              }
              /**
               * @dev Stores a new address in the EIP1967 implementation slot.
               */
              function _setImplementation(address newImplementation) private {
                  require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                  StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
              }
              /**
               * @dev Perform implementation upgrade
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeTo(address newImplementation) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
              }
              /**
               * @dev Perform implementation upgrade with additional setup call.
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(newImplementation, data);
                  }
              }
              /**
               * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
                  address oldImplementation = _getImplementation();
                  // Initial upgrade and setup call
                  _setImplementation(newImplementation);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(newImplementation, data);
                  }
                  // Perform rollback test if not already in progress
                  StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                  if (!rollbackTesting.value) {
                      // Trigger rollback using upgradeTo from the new implementation
                      rollbackTesting.value = true;
                      Address.functionDelegateCall(
                          newImplementation,
                          abi.encodeWithSignature(
                              "upgradeTo(address)",
                              oldImplementation
                          )
                      );
                      rollbackTesting.value = false;
                      // Check rollback was effective
                      require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                      // Finally reset to the new implementation and log the upgrade
                      _setImplementation(newImplementation);
                      emit Upgraded(newImplementation);
                  }
              }
              /**
               * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
               * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
               *
               * Emits a {BeaconUpgraded} event.
               */
              function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
                  _setBeacon(newBeacon);
                  emit BeaconUpgraded(newBeacon);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                  }
              }
              /**
               * @dev Storage slot with the admin of the contract.
               * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
               * validated in the constructor.
               */
              bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
              /**
               * @dev Emitted when the admin account has changed.
               */
              event AdminChanged(address previousAdmin, address newAdmin);
              /**
               * @dev Returns the current admin.
               */
              function _getAdmin() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
              }
              /**
               * @dev Stores a new address in the EIP1967 admin slot.
               */
              function _setAdmin(address newAdmin) private {
                  require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                  StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
              }
              /**
               * @dev Changes the admin of the proxy.
               *
               * Emits an {AdminChanged} event.
               */
              function _changeAdmin(address newAdmin) internal {
                  emit AdminChanged(_getAdmin(), newAdmin);
                  _setAdmin(newAdmin);
              }
              /**
               * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
               * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
               */
              bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
              /**
               * @dev Emitted when the beacon is upgraded.
               */
              event BeaconUpgraded(address indexed beacon);
              /**
               * @dev Returns the current beacon.
               */
              function _getBeacon() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
              }
              /**
               * @dev Stores a new beacon in the EIP1967 beacon slot.
               */
              function _setBeacon(address newBeacon) private {
                  require(
                      Address.isContract(newBeacon),
                      "ERC1967: new beacon is not a contract"
                  );
                  require(
                      Address.isContract(IBeacon(newBeacon).implementation()),
                      "ERC1967: beacon implementation is not a contract"
                  );
                  StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This is the interface that {BeaconProxy} expects of its beacon.
           */
          interface IBeacon {
              /**
               * @dev Must return an address that can be used as a delegate call target.
               *
               * {BeaconProxy} will check that this address is a contract.
               */
              function implementation() external view returns (address);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev Collection of functions related to the address type
           */
          library Address {
              /**
               * @dev Returns true if `account` is a contract.
               *
               * [IMPORTANT]
               * ====
               * It is unsafe to assume that an address for which this function returns
               * false is an externally-owned account (EOA) and not a contract.
               *
               * Among others, `isContract` will return false for the following
               * types of addresses:
               *
               *  - an externally-owned account
               *  - a contract in construction
               *  - an address where a contract will be created
               *  - an address where a contract lived, but was destroyed
               * ====
               */
              function isContract(address account) internal view returns (bool) {
                  // This method relies on extcodesize, which returns 0 for contracts in
                  // construction, since the code is only stored at the end of the
                  // constructor execution.
                  uint256 size;
                  // solhint-disable-next-line no-inline-assembly
                  assembly { size := extcodesize(account) }
                  return size > 0;
              }
              /**
               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
               * `recipient`, forwarding all available gas and reverting on errors.
               *
               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
               * of certain opcodes, possibly making contracts go over the 2300 gas limit
               * imposed by `transfer`, making them unable to receive funds via
               * `transfer`. {sendValue} removes this limitation.
               *
               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
               *
               * IMPORTANT: because control is transferred to `recipient`, care must be
               * taken to not create reentrancy vulnerabilities. Consider using
               * {ReentrancyGuard} or the
               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
               */
              function sendValue(address payable recipient, uint256 amount) internal {
                  require(address(this).balance >= amount, "Address: insufficient balance");
                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                  (bool success, ) = recipient.call{ value: amount }("");
                  require(success, "Address: unable to send value, recipient may have reverted");
              }
              /**
               * @dev Performs a Solidity function call using a low level `call`. A
               * plain`call` is an unsafe replacement for a function call: use this
               * function instead.
               *
               * If `target` reverts with a revert reason, it is bubbled up by this
               * function (like regular Solidity function calls).
               *
               * Returns the raw returned data. To convert to the expected return value,
               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
               *
               * Requirements:
               *
               * - `target` must be a contract.
               * - calling `target` with `data` must not revert.
               *
               * _Available since v3.1._
               */
              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                return functionCall(target, data, "Address: low-level call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
               * `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, 0, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but also transferring `value` wei to `target`.
               *
               * Requirements:
               *
               * - the calling contract must have an ETH balance of at least `value`.
               * - the called Solidity function must be `payable`.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
              }
              /**
               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
               * with `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                  require(address(this).balance >= value, "Address: insufficient balance for call");
                  require(isContract(target), "Address: call to non-contract");
                  // solhint-disable-next-line avoid-low-level-calls
                  (bool success, bytes memory returndata) = target.call{ value: value }(data);
                  return _verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                  return functionStaticCall(target, data, "Address: low-level static call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                  require(isContract(target), "Address: static call to non-contract");
                  // solhint-disable-next-line avoid-low-level-calls
                  (bool success, bytes memory returndata) = target.staticcall(data);
                  return _verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but performing a delegate call.
               *
               * _Available since v3.4._
               */
              function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                  return functionDelegateCall(target, data, "Address: low-level delegate call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
               * but performing a delegate call.
               *
               * _Available since v3.4._
               */
              function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                  require(isContract(target), "Address: delegate call to non-contract");
                  // solhint-disable-next-line avoid-low-level-calls
                  (bool success, bytes memory returndata) = target.delegatecall(data);
                  return _verifyCallResult(success, returndata, errorMessage);
              }
              function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                  if (success) {
                      return returndata;
                  } else {
                      // Look for revert reason and bubble it up if present
                      if (returndata.length > 0) {
                          // The easiest way to bubble the revert reason is using memory via assembly
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev Library for reading and writing primitive types to specific storage slots.
           *
           * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
           * This library helps with reading and writing to such slots without the need for inline assembly.
           *
           * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
           *
           * Example usage to set ERC1967 implementation slot:
           * ```
           * contract ERC1967 {
           *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
           *
           *     function _getImplementation() internal view returns (address) {
           *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
           *     }
           *
           *     function _setImplementation(address newImplementation) internal {
           *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
           *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
           *     }
           * }
           * ```
           *
           * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
           */
          library StorageSlot {
              struct AddressSlot {
                  address value;
              }
              struct BooleanSlot {
                  bool value;
              }
              struct Bytes32Slot {
                  bytes32 value;
              }
              struct Uint256Slot {
                  uint256 value;
              }
              /**
               * @dev Returns an `AddressSlot` with member `value` located at `slot`.
               */
              function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
               */
              function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
               */
              function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
               */
              function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/Context.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable is Context {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              constructor () {
                  address msgSender = _msgSender();
                  _owner = msgSender;
                  emit OwnershipTransferred(address(0), msgSender);
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  emit OwnershipTransferred(_owner, address(0));
                  _owner = address(0);
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  emit OwnershipTransferred(_owner, newOwner);
                  _owner = newOwner;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /*
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract Context {
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                  return msg.data;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../ERC1967/ERC1967Upgrade.sol";
          /**
           * @dev Base contract for building openzeppelin-upgrades compatible implementations for the {ERC1967Proxy}. It includes
           * publicly available upgrade functions that are called by the plugin and by the secure upgrade mechanism to verify
           * continuation of the upgradability.
           *
           * The {_authorizeUpgrade} function MUST be overridden to include access restriction to the upgrade mechanism.
           *
           * _Available since v4.1._
           */
          abstract contract UUPSUpgradeable is ERC1967Upgrade {
              function upgradeTo(address newImplementation) external virtual {
                  _authorizeUpgrade(newImplementation);
                  _upgradeToAndCallSecure(newImplementation, bytes(""), false);
              }
              function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual {
                  _authorizeUpgrade(newImplementation);
                  _upgradeToAndCallSecure(newImplementation, data, true);
              }
              function _authorizeUpgrade(address newImplementation) internal virtual;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.2;
          import "@openzeppelin/contracts/proxy/utils/UUPSUpgradeable.sol";
          abstract contract Proxiable is UUPSUpgradeable {
              function _authorizeUpgrade(address newImplementation) internal override {
                  _beforeUpgrade(newImplementation);
              }
              function _beforeUpgrade(address newImplementation) internal virtual;
          }
          contract ChildOfProxiable is Proxiable {
              function _beforeUpgrade(address newImplementation) internal virtual override {}
          }
          

          File 2 of 4: zStakeCorePool
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "./zStakePoolBase.sol";
          /**
           * @title Wild Core Pool - Fork of Illuvium Core Pool
           *
           * @notice Core pools represent permanent pools like WILD or WILD/ETH Pair pool,
           *      core pools allow staking for arbitrary periods of time up to 1 year
           *
           * @dev See WildPoolBase for more details
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          contract zStakeCorePool is zStakePoolBase {
            /// @dev Flag indicating pool type, false means "core pool"
            bool public constant override isFlashPool = false;
            /// @dev Pool tokens value available in the pool;
            ///      pool token examples are WILD (WILD core pool) or WILD/ETH pair (LP core pool)
            /// @dev For LP core pool this value doesnt' count for WILD tokens received as Vault rewards
            ///      while for WILD core pool it does count for such tokens as well
            uint256 public poolTokenReserve;
            /**
             * @dev Creates/deploys an instance of the core pool
             *
             * @param _rewardToken WILD ERC20 Token address
             * @param _factory Pool factory zStakePoolFactory instance/address
             * @param _poolToken token the pool operates on, for example WILD or WILD/ETH pair
             * @param _initBlock initial block used to calculate the rewards
             * @param _weight number representing a weight of the pool, actual weight fraction
             *      is calculated as that number divided by the total pools weight and doesn't exceed one
             */
            function initialize(
              address _rewardToken,
              zStakePoolFactory _factory,
              address _poolToken,
              uint64 _initBlock,
              uint32 _weight
            ) initializer public {
              __zStakePoolBase__init(_rewardToken, _factory, _poolToken, _initBlock, _weight);
            }
            // Call this on the implementation contract (not the proxy)
            function initializeImplementation() public initializer {
              __Ownable_init();
              _pause();
            }
            /**
             * @notice Service function to calculate and pay pending vault and yield rewards to the sender
             *
             * @dev Internally executes similar function `_processRewards` from the parent smart contract
             *      to calculate and pay yield rewards; adds vault rewards processing
             *
             * @dev Can be executed by anyone at any time, but has an effect only when
             *      executed by deposit holder and when at least one block passes from the
             *      previous reward processing
             * @dev Executed internally when "staking as a pool" (`stakeAsPool`)
             * @dev When timing conditions are not met (executed too frequently, or after factory
             *      end block), function doesn't throw and exits silently
             */
            function processRewards() external override {
              require(!paused(), "contract is paused");
              _processRewards(msg.sender, true);
            }
            /**
             * @dev Executed internally by the pool itself (from the parent `zStakePoolBase` smart contract)
             *      as part of yield rewards processing logic (`zStakePoolBase._processRewards` function)
             *
             * @param _staker an address which stakes (the yield reward)
             * @param _amount amount to be staked (yield reward amount)
             */
            function stakeAsPool(address _staker, uint256 _amount) external {
              require(!paused(), "contract is paused");
              require(factory.poolExists(msg.sender), "access denied");
              _sync();
              User storage user = users[_staker];
              if (user.tokenAmount > 0) {
                _processRewards(_staker, false);
              }
              uint256 depositWeight = _amount * YEAR_STAKE_WEIGHT_MULTIPLIER;
              Deposit memory newDeposit = Deposit({
                tokenAmount: _amount,
                lockedFrom: uint64(now256()),
                lockedUntil: uint64(now256() + rewardLockPeriod),
                weight: depositWeight,
                isYield: true
              });
              user.tokenAmount += _amount;
              user.totalWeight += depositWeight;
              user.deposits.push(newDeposit);
              usersLockingWeight += depositWeight;
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              // update `poolTokenReserve` only if this is a LP Core Pool (stakeAsPool can be executed only for LP pool)
              poolTokenReserve += _amount;
            }
            /**
             * @inheritdoc zStakePoolBase
             *
             * @dev Additionally to the parent smart contract, updates vault rewards of the holder,
             *      and updates (increases) pool token reserve (pool tokens value available in the pool)
             */
            function _stake(
              address _staker,
              uint256 _amount,
              uint64 _lockedUntil,
              bool _isYield
            ) internal override {
              super._stake(_staker, _amount, _lockedUntil, _isYield);
              poolTokenReserve += _amount;
            }
            /**
             * @inheritdoc zStakePoolBase
             *
             * @dev Additionally to the parent smart contract, updates vault rewards of the holder,
             *      and updates (decreases) pool token reserve (pool tokens value available in the pool)
             */
            function _unstake(
              address _staker,
              uint256 _depositId,
              uint256 _amount
            ) internal override {
              User storage user = users[_staker];
              Deposit memory stakeDeposit = user.deposits[_depositId];
              require(
                stakeDeposit.lockedFrom == 0 || now256() > stakeDeposit.lockedUntil,
                "deposit not yet unlocked"
              );
              poolTokenReserve -= _amount;
              super._unstake(_staker, _depositId, _amount);
            }
            /**
             * @inheritdoc zStakePoolBase
             *
             * @dev Additionally to the parent smart contract, processes vault rewards of the holder,
             *      and for reward pool pool updates (increases) pool token reserve (pool tokens value available in the pool)
             */
            function _processRewards(address _staker, bool _withUpdate)
              internal
              override
              returns (uint256 pendingYield)
            {
              pendingYield = super._processRewards(_staker, _withUpdate);
              // update `poolTokenReserve` only if this is the reward Pool
              if (poolToken == rewardToken) {
                poolTokenReserve += pendingYield;
              }
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "./interfaces/IPool.sol";
          import "./interfaces/ICorePool.sol";
          import "./ReentrancyGuardUpgradeable.sol";
          import "./zStakePoolFactory.sol";
          import "./utils/SafeERC20.sol";
          import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
          /**
           * @title Pool Base - Fork of Illuvium Pool Base
           *
           * @notice An abstract contract containing common logic for a staking pool
           *
           * @dev Deployment and initialization.
           *      Any pool deployed must be bound to the deployed pool factory (zStakePoolFactory)
           *      Additionally, 3 token instance addresses must be defined on deployment:
           *          - Reward token address
           *          - pool token address, it can be the reward token address, LP pair address, and others
           *
           * @dev Pool weight defines the fraction of the yield current pool receives among the other pools,
           *      pool factory is responsible for the weight synchronization between the pools.
           * @dev The weight is logically 10% for reward token pool and 90% for LP pool.
           *      Since Solidity doesn't support fractions the weight is defined by the division of
           *      pool weight by total pools weight (sum of all registered pools within the factory)
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          abstract contract zStakePoolBase is
            IPool,
            ReentrancyGuardUpgradeable,
            OwnableUpgradeable,
            PausableUpgradeable
          {
            /// @dev Data structure representing token holder using a pool
            struct User {
              // @dev Total staked amount
              uint256 tokenAmount;
              // @dev Total weight
              uint256 totalWeight;
              // @dev Auxiliary variable for yield calculation
              uint256 subYieldRewards;
              // @dev An array of holder's deposits
              Deposit[] deposits;
            }
            function isFlashPool() external view virtual override returns (bool) {
              return false;
            }
            /// @dev The reward token
            address public override rewardToken;
            /// @dev Token holder storage, maps token holder address to their data record
            mapping(address => User) public users;
            /// @dev Link to the pool factory zStakePoolFactory instance
            zStakePoolFactory public factory;
            /// @dev Link to the pool token instance, for example WILD or WILD/ETH pair
            address public override poolToken;
            /// @dev Pool weight
            uint32 public override weight;
            /// @dev Block number of the last yield distribution event
            uint64 public override lastYieldDistribution;
            /// @dev Used to calculate yield rewards
            /// @dev This value is different from "reward per token" used in locked pool
            /// @dev Note: stakes are different in duration and "weight" reflects that
            uint256 public override yieldRewardsPerWeight;
            /// @dev Used to calculate yield rewards, keeps track of the tokens weight locked in staking
            uint256 public override usersLockingWeight;
            /// @dev The duration of time to lock rewards
            uint256 public rewardLockPeriod;
            /**
             * @dev Stake weight is proportional to deposit amount and time locked, precisely
             *      "deposit amount wei multiplied by (fraction of the year locked plus one)"
             * @dev To avoid significant precision loss due to multiplication by "fraction of the year" [0, 1],
             *      weight is stored multiplied by 1e6 constant, as an integer
             * @dev Corner case 1: if time locked is zero, weight is deposit amount multiplied by 1e6
             * @dev Corner case 2: if time locked is one year, fraction of the year locked is one, and
             *      weight is a deposit amount multiplied by 2 * 1e6
             */
            uint256 internal constant WEIGHT_MULTIPLIER = 1e6;
            /**
             * @dev When we know beforehand that staking is done for a year, and fraction of the year locked is one,
             *      we use simplified calculation and use the following constant instead previos one
             */
            uint256 internal constant YEAR_STAKE_WEIGHT_MULTIPLIER = 2 * WEIGHT_MULTIPLIER;
            /**
             * @dev Rewards per weight are stored multiplied by 1e12, as integers.
             */
            uint256 internal constant REWARD_PER_WEIGHT_MULTIPLIER = 1e12;
            /**
             * @dev Fired in _stake() and stake()
             *
             * @param _by an address which performed an operation, usually token holder
             * @param _from token holder address, the tokens will be returned to that address
             * @param amount amount of tokens staked
             */
            event Staked(address indexed _by, address indexed _from, uint256 amount);
            /**
             * @dev Fired in _updateStakeLock() and updateStakeLock()
             *
             * @param _by an address which performed an operation
             * @param depositId updated deposit ID
             * @param lockedFrom deposit locked from value
             * @param lockedUntil updated deposit locked until value
             */
            event StakeLockUpdated(
              address indexed _by,
              uint256 depositId,
              uint64 lockedFrom,
              uint64 lockedUntil
            );
            /**
             * @dev Fired in _unstake() and unstake()
             *
             * @param _by an address which performed an operation, usually token holder
             * @param _to an address which received the unstaked tokens, usually token holder
             * @param amount amount of tokens unstaked
             */
            event Unstaked(address indexed _by, address indexed _to, uint256 amount);
            /**
             * @dev Fired in _sync(), sync() and dependent functions (stake, unstake, etc.)
             *
             * @param _by an address which performed an operation
             * @param yieldRewardsPerWeight updated yield rewards per weight value
             * @param lastYieldDistribution usually, current block number
             */
            event Synchronized(
              address indexed _by,
              uint256 yieldRewardsPerWeight,
              uint64 lastYieldDistribution
            );
            /**
             * @dev Fired in _processRewards(), processRewards() and dependent functions (stake, unstake, etc.)
             *
             * @param _by an address which performed an operation
             * @param _to an address which claimed the yield reward
             * @param amount amount of yield paid
             */
            event YieldClaimed(address indexed _by, address indexed _to, uint256 amount);
            /**
             * @dev Fired in setWeight()
             *
             * @param _by an address which performed an operation, always a factory
             * @param _fromVal old pool weight value
             * @param _toVal new pool weight value
             */
            event PoolWeightUpdated(address indexed _by, uint32 _fromVal, uint32 _toVal);
            /**
             * @dev Overridden in sub-contracts to construct the pool
             *
             * @param _rewardToken Reward ERC20 Token address
             * @param _factory Pool factory zStakePoolFactory instance/address
             * @param _poolToken token the pool operates on, for example WILD or WILD/ETH pair
             * @param _initBlock initial block used to calculate the rewards
             *      note: _initBlock can be set to the future effectively meaning _sync() calls will do nothing
             * @param _weight number representing a weight of the pool, actual weight fraction
             *      is calculated as that number divided by the total pools weight and doesn't exceed one
             */
            function __zStakePoolBase__init(
              address _rewardToken,
              zStakePoolFactory _factory,
              address _poolToken,
              uint64 _initBlock,
              uint32 _weight
            ) public initializer {
              __Ownable_init();
              // verify the inputs are set
              require(address(_factory) != address(0), "factory address not set");
              require(_poolToken != address(0), "pool token address not set");
              require(_initBlock > 0, "init block not set");
              require(_weight > 0, "pool weight not set");
              // save the inputs into internal state variables
              factory = _factory;
              poolToken = _poolToken;
              weight = _weight;
              rewardToken = _rewardToken;
              // init the dependent internal state variables
              lastYieldDistribution = _initBlock;
              rewardLockPeriod = 365 days;
            }
            /**
             * @notice Calculates current yield rewards value available for address specified
             *
             * @param _staker an address to calculate yield rewards value for
             * @return calculated yield reward value for the given address
             */
            function pendingYieldRewards(address _staker) external view override returns (uint256) {
              // `newYieldRewardsPerWeight` will store stored or recalculated value for `yieldRewardsPerWeight`
              uint256 newYieldRewardsPerWeight;
              // if smart contract state was not updated recently, `yieldRewardsPerWeight` value
              // is outdated and we need to recalculate it in order to calculate pending rewards correctly
              if (blockNumber() > lastYieldDistribution && usersLockingWeight != 0) {
                uint256 multiplier = blockNumber() - lastYieldDistribution;
                uint256 rewards = (multiplier * weight * factory.getRewardTokensPerBlock()) /
                  factory.totalWeight();
                // recalculated value for `yieldRewardsPerWeight`
                newYieldRewardsPerWeight =
                  rewardToWeight(rewards, usersLockingWeight) +
                  yieldRewardsPerWeight;
              } else {
                // if smart contract state is up to date, we don't recalculate
                newYieldRewardsPerWeight = yieldRewardsPerWeight;
              }
              // based on the rewards per weight value, calculate pending rewards;
              User memory user = users[_staker];
              uint256 pending = weightToReward(user.totalWeight, newYieldRewardsPerWeight) -
                user.subYieldRewards;
              return pending;
            }
            /**
             * @notice Returns total staked token balance for the given address
             *
             * @param _user an address to query balance for
             * @return total staked token balance
             */
            function balanceOf(address _user) external view override returns (uint256) {
              // read specified user token amount and return
              return users[_user].tokenAmount;
            }
            /**
             * @notice Returns information on the given deposit for the given address
             *
             * @dev See getDepositsLength
             *
             * @param _user an address to query deposit for
             * @param _depositId zero-indexed deposit ID for the address specified
             * @return deposit info as Deposit structure
             */
            function getDeposit(address _user, uint256 _depositId)
              external
              view
              override
              returns (Deposit memory)
            {
              // read deposit at specified index and return
              return users[_user].deposits[_depositId];
            }
            /**
             * @notice Returns number of deposits for the given address. Allows iteration over deposits.
             *
             * @dev See getDeposit
             *
             * @param _user an address to query deposit length for
             * @return number of deposits for the given address
             */
            function getDepositsLength(address _user) external view override returns (uint256) {
              // read deposits array length and return
              return users[_user].deposits.length;
            }
            /**
             * @notice Stakes specified amount of tokens for the specified amount of time,
             *      and pays pending yield rewards if any
             *
             * @dev Requires amount to stake to be greater than zero
             *
             * @param _amount amount of tokens to stake
             * @param _lockUntil stake period as unix timestamp; zero means no locking
             */
            function stake(uint256 _amount, uint64 _lockUntil) external override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _stake(msg.sender, _amount, _lockUntil, false);
            }
            /**
             * @notice Unstakes specified amount of tokens, and pays pending yield rewards if any
             *
             * @dev Requires amount to unstake to be greater than zero
             *
             * @param _depositId deposit ID to unstake from, zero-indexed
             * @param _amount amount of tokens to unstake
             */
            function unstake(uint256 _depositId, uint256 _amount) external override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _unstake(msg.sender, _depositId, _amount);
            }
            /**
             * @notice Extends locking period for a given deposit
             *
             * @dev Requires new lockedUntil value to be:
             *      higher than the current one, and
             *      in the future, but
             *      no more than 1 year in the future
             *
             * @param depositId updated deposit ID
             * @param lockedUntil updated deposit locked until value
             */
            function updateStakeLock(uint256 depositId, uint64 lockedUntil) external {
              require(!paused(), "contract is paused");
              // Sync and give user rewards
              _sync();
              _processRewards(msg.sender, false);
              // delegate call to an internal function
              _updateStakeLock(msg.sender, depositId, lockedUntil);
              // Update subyieldrewards so that the user is not owed anything
              User storage user = users[msg.sender];
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
            }
            /**
             * @notice Service function to synchronize pool state with current time
             *
             * @dev Can be executed by anyone at any time, but has an effect only when
             *      at least one block passes between synchronizations
             * @dev Executed internally when staking, unstaking, processing rewards in order
             *      for calculations to be correct and to reflect state progress of the contract
             * @dev When timing conditions are not met (executed too frequently, or after factory
             *      end block), function doesn't throw and exits silently
             */
            function sync() external override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _sync();
            }
            /**
             * @notice Service function to calculate and pay pending yield rewards to the sender
             *
             * @dev Can be executed by anyone at any time, but has an effect only when
             *      executed by deposit holder and when at least one block passes from the
             *      previous reward processing
             * @dev Executed internally when staking and unstaking, executes sync() under the hood
             *      before making further calculations and payouts
             * @dev When timing conditions are not met (executed too frequently, or after factory
             *      end block), function doesn't throw and exits silently
             *
             */
            function processRewards() external virtual override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _processRewards(msg.sender, true);
            }
            /**
             * @dev Executed by the factory to modify pool weight; the factory is expected
             *      to keep track of the total pools weight when updating
             *
             * @dev Set weight to zero to disable the pool
             *
             * @param _weight new weight to set for the pool
             */
            function setWeight(uint32 _weight) external override {
              require(!paused(), "contract is paused");
              // verify function is executed by the factory
              require(msg.sender == address(factory), "access denied");
              // emit an event logging old and new weight values
              emit PoolWeightUpdated(msg.sender, weight, _weight);
              // set the new weight value
              weight = _weight;
            }
            /**
             * @dev Similar to public pendingYieldRewards, but performs calculations based on
             *      current smart contract state only, not taking into account any additional
             *      time/blocks which might have passed
             *
             * @param _staker an address to calculate yield rewards value for
             * @return pending calculated yield reward value for the given address
             */
            function _pendingYieldRewards(address _staker) internal view returns (uint256 pending) {
              // read user data structure into memory
              User memory user = users[_staker];
              // and perform the calculation using the values read
              return weightToReward(user.totalWeight, yieldRewardsPerWeight) - user.subYieldRewards;
            }
            /**
             * @dev Used internally, mostly by children implementations, see stake()
             *
             * @param _staker an address which stakes tokens and which will receive them back
             * @param _amount amount of tokens to stake
             * @param _lockUntil stake period as unix timestamp; zero means no locking
             * @param _isYield a flag indicating if that stake is created to store yield reward
             *      from the previously unstaked stake
             */
            function _stake(
              address _staker,
              uint256 _amount,
              uint64 _lockUntil,
              bool _isYield
            ) internal virtual {
              // validate the inputs
              require(_amount > 0, "zero amount");
              require(
                _lockUntil == 0 || (_lockUntil > now256() && _lockUntil - now256() <= 365 days),
                "invalid lock interval"
              );
              // update smart contract state
              _sync();
              // get a link to user data struct, we will write to it later
              User storage user = users[_staker];
              // process current pending rewards if any
              if (user.tokenAmount > 0) {
                _processRewards(_staker, false);
              }
              // in most of the cases added amount `addedAmount` is simply `_amount`
              // however for deflationary tokens this can be different
              // read the current balance
              uint256 previousBalance = IERC20(poolToken).balanceOf(address(this));
              // transfer `_amount`; note: some tokens may get burnt here
              transferPoolTokenFrom(address(msg.sender), address(this), _amount);
              // read new balance, usually this is just the difference `previousBalance - _amount`
              uint256 newBalance = IERC20(poolToken).balanceOf(address(this));
              // calculate real amount taking into account deflation
              uint256 addedAmount = newBalance - previousBalance;
              // set the `lockFrom` and `lockUntil` taking into account that
              // zero value for `_lockUntil` means "no locking" and leads to zero values
              // for both `lockFrom` and `lockUntil`
              uint64 lockFrom = _lockUntil > 0 ? uint64(now256()) : 0;
              uint64 lockUntil = _lockUntil;
              // stake weight formula rewards for locking
              uint256 stakeWeight = (((lockUntil - lockFrom) * WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * addedAmount;
              // makes sure stakeWeight is valid
              assert(stakeWeight > 0);
              // create and save the deposit (append it to deposits array)
              Deposit memory deposit = Deposit({
                tokenAmount: addedAmount,
                weight: stakeWeight,
                lockedFrom: lockFrom,
                lockedUntil: lockUntil,
                isYield: _isYield
              });
              // deposit ID is an index of the deposit in `deposits` array
              user.deposits.push(deposit);
              // update user record
              user.tokenAmount += addedAmount;
              user.totalWeight += stakeWeight;
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              // update global variable
              usersLockingWeight += stakeWeight;
              // emit an event
              emit Staked(msg.sender, _staker, _amount);
            }
            /**
             * @dev Allows for the rewardLockPeriod to be modified.
             */
            function changeRewardLockPeriod(uint256 _rewardLockPeriod) external onlyOwner {
              require(rewardLockPeriod != _rewardLockPeriod, "same rewardLockPeriod");
              require(_rewardLockPeriod <= 365 days, "too long lock period");
              rewardLockPeriod = _rewardLockPeriod;
            }
            /**
             * @dev Used internally, mostly by children implementations, see unstake()
             *
             * @param _staker an address which unstakes tokens (which previously staked them)
             * @param _depositId deposit ID to unstake from, zero-indexed
             * @param _amount amount of tokens to unstake
             */
            function _unstake(
              address _staker,
              uint256 _depositId,
              uint256 _amount
            ) internal virtual {
              // verify an amount is set
              require(_amount > 0, "zero amount");
              // get a link to user data struct, we will write to it later
              User storage user = users[_staker];
              // get a link to the corresponding deposit, we may write to it later
              Deposit storage stakeDeposit = user.deposits[_depositId];
              // deposit structure may get deleted, so we save isYield flag to be able to use it
              bool isYield = stakeDeposit.isYield;
              // verify available balance
              // if staker address ot deposit doesn't exist this check will fail as well
              require(stakeDeposit.tokenAmount >= _amount, "amount exceeds stake");
              // update smart contract state
              _sync();
              // and process current pending rewards if any
              _processRewards(_staker, false);
              // recalculate deposit weight
              uint256 previousWeight = stakeDeposit.weight;
              uint256 newWeight = (((stakeDeposit.lockedUntil - stakeDeposit.lockedFrom) *
                WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * (stakeDeposit.tokenAmount - _amount);
              // update the deposit, or delete it if its depleted
              if (stakeDeposit.tokenAmount - _amount == 0) {
                delete user.deposits[_depositId];
              } else {
                stakeDeposit.tokenAmount -= _amount;
                stakeDeposit.weight = newWeight;
              }
              // update user record
              user.tokenAmount -= _amount;
              user.totalWeight = user.totalWeight - previousWeight + newWeight;
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              // update global variable
              usersLockingWeight = usersLockingWeight - previousWeight + newWeight;
              // if the deposit was created by the pool itself as a yield reward
              if (isYield) {
                // @TODO: Replace this
                // Make it so it transfers tokens from escrow rewards pool to staker
                // mint the yield via the factory
                factory.transferRewardYield(msg.sender, _amount);
              } else {
                // otherwise just return tokens back to holder
                transferPoolToken(msg.sender, _amount);
              }
              // emit an event
              emit Unstaked(msg.sender, _staker, _amount);
            }
            /**
             * @dev Used internally, mostly by children implementations, see sync()
             *
             * @dev Updates smart contract state (`yieldRewardsPerWeight`, `lastYieldDistribution`),
             */
            function _sync() internal virtual {
              if (blockNumber() <= lastYieldDistribution) {
                return;
              }
              // if locking weight is zero - update only `lastYieldDistribution` and exit
              if (usersLockingWeight == 0) {
                lastYieldDistribution = uint64(blockNumber());
                return;
              }
              // to calculate the reward we need to know how many blocks passed, and reward per block
              uint256 currentBlock = blockNumber();
              uint256 blocksPassed = currentBlock - lastYieldDistribution;
              uint256 rewardPerBlock = factory.getRewardTokensPerBlock();
              // calculate the reward
              uint256 rewardAmount = (blocksPassed * rewardPerBlock * weight) / factory.totalWeight();
              // update rewards per weight and `lastYieldDistribution`
              yieldRewardsPerWeight += rewardToWeight(rewardAmount, usersLockingWeight);
              lastYieldDistribution = uint64(currentBlock);
              // emit an event
              emit Synchronized(msg.sender, yieldRewardsPerWeight, lastYieldDistribution);
            }
            /**
             * @dev Used internally, mostly by children implementations, see processRewards()
             *
             * @param _staker an address which receives the reward (which has staked some tokens earlier)
             * @param _withUpdate flag allowing to disable synchronization (see sync()) if set to false
             * @return pendingYield the rewards calculated and optionally re-staked
             */
            function _processRewards(address _staker, bool _withUpdate)
              internal
              virtual
              returns (uint256 pendingYield)
            {
              // update smart contract state if required
              if (_withUpdate) {
                _sync();
              }
              // calculate pending yield rewards, this value will be returned
              pendingYield = _pendingYieldRewards(_staker);
              // if pending yield is zero - just return silently
              if (pendingYield == 0) return 0;
              // get link to a user data structure, we will write into it later
              User storage user = users[_staker];
              if (poolToken == rewardToken) {
                // calculate pending yield weight,
                // 2e6 is the bonus weight when staking for 1 year
                uint256 depositWeight = pendingYield * YEAR_STAKE_WEIGHT_MULTIPLIER;
                // if the pool is the Reward Token Pool - create new Reward Token deposit
                // and save it - push it into deposits array
                Deposit memory newDeposit = Deposit({
                  tokenAmount: pendingYield,
                  lockedFrom: uint64(now256()),
                  lockedUntil: uint64(now256() + rewardLockPeriod), // staking yield for 1 year
                  weight: depositWeight,
                  isYield: true
                });
                user.deposits.push(newDeposit);
                // update user record
                user.tokenAmount += pendingYield;
                user.totalWeight += depositWeight;
                // update global variable
                usersLockingWeight += depositWeight;
              } else {
                // for other pools - stake as pool
                // This will stake the rewards into the reward token pool
                address rewardPool = factory.getPoolAddress(rewardToken);
                ICorePool(rewardPool).stakeAsPool(_staker, pendingYield);
              }
              // update users's record for `subYieldRewards` if requested
              if (_withUpdate) {
                user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              }
              // emit an event
              emit YieldClaimed(msg.sender, _staker, pendingYield);
            }
            /**
             * @dev See updateStakeLock()
             *
             * @param _staker an address to update stake lock
             * @param _depositId updated deposit ID
             * @param _lockedUntil updated deposit locked until value
             */
            function _updateStakeLock(
              address _staker,
              uint256 _depositId,
              uint64 _lockedUntil
            ) internal {
              // validate the input time
              require(_lockedUntil > now256(), "lock should be in the future");
              // get a link to user data struct, we will write to it later
              User storage user = users[_staker];
              // get a link to the corresponding deposit, we may write to it later
              Deposit storage stakeDeposit = user.deposits[_depositId];
              // validate the input against deposit structure
              require(_lockedUntil > stakeDeposit.lockedUntil, "invalid new lock");
              // verify locked from and locked until values
              if (stakeDeposit.lockedFrom == 0) {
                // Was never locked
                require(_lockedUntil - now256() <= 365 days, "max lock period is 365 days");
                stakeDeposit.lockedFrom = uint64(now256());
              } else {
                // Was locked (but for less than 365 days)
                require(_lockedUntil - stakeDeposit.lockedFrom <= 365 days, "max lock period is 365 days");
              }
              // update locked until value, calculate new weight
              stakeDeposit.lockedUntil = _lockedUntil;
              uint256 newWeight = (((stakeDeposit.lockedUntil - stakeDeposit.lockedFrom) *
                WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * stakeDeposit.tokenAmount;
              // save previous weight
              uint256 previousWeight = stakeDeposit.weight;
              // update weight
              stakeDeposit.weight = newWeight;
              // update user total weight and global locking weight
              user.totalWeight = user.totalWeight - previousWeight + newWeight;
              usersLockingWeight = usersLockingWeight - previousWeight + newWeight;
              // emit an event
              emit StakeLockUpdated(_staker, _depositId, stakeDeposit.lockedFrom, _lockedUntil);
            }
            /**
             * @dev Converts stake weight (not to be mixed with the pool weight) to
             *      token reward value, applying the 10^12 division on weight
             *
             * @param _weight stake weight
             * @param rewardPerWeight reward per weight
             * @return reward value normalized to 10^12
             */
            function weightToReward(uint256 _weight, uint256 rewardPerWeight) public pure returns (uint256) {
              // apply the formula and return
              return (_weight * rewardPerWeight) / REWARD_PER_WEIGHT_MULTIPLIER;
            }
            /**
             * @dev Converts reward value to stake weight (not to be mixed with the pool weight),
             *      applying the 10^12 multiplication on the reward
             *      - OR -
             * @dev Converts reward value to reward/weight if stake weight is supplied as second
             *      function parameter instead of reward/weight
             *
             * @param reward yield reward
             * @param rewardPerWeight reward/weight (or stake weight)
             * @return stake weight (or reward/weight)
             */
            function rewardToWeight(uint256 reward, uint256 rewardPerWeight) public pure returns (uint256) {
              // apply the reverse formula and return
              return (reward * REWARD_PER_WEIGHT_MULTIPLIER) / rewardPerWeight;
            }
            /**
             * @dev Testing time-dependent functionality is difficult and the best way of
             *      doing it is to override block number in helper test smart contracts
             *
             * @return `block.number` in mainnet, custom values in testnets (if overridden)
             */
            function blockNumber() public view virtual returns (uint256) {
              // return current block number
              return block.number;
            }
            /**
             * @dev Testing time-dependent functionality is difficult and the best way of
             *      doing it is to override time in helper test smart contracts
             *
             * @return `block.timestamp` in mainnet, custom values in testnets (if overridden)
             */
            function now256() public view virtual returns (uint256) {
              // return current block timestamp
              return block.timestamp;
            }
            /**
             * @dev Sets the pause status of the contract.
             */
            function setPauseStatus(bool toPause) public onlyOwner {
              if (toPause) {
                require(!paused(), "Pausable: paused");
                _pause();
              } else {
                require(paused(), "Pausable: not paused");
                _unpause();
              }
            }
            /**
             * @dev Executes SafeERC20.safeTransfer on a pool token
             *
             * @dev Reentrancy safety enforced via `ReentrancyGuard.nonReentrant`
             */
            function transferPoolToken(address _to, uint256 _value) internal nonReentrant {
              // just delegate call to the target
              SafeERC20.safeTransfer(IERC20(poolToken), _to, _value);
            }
            /**
             * @dev Executes SafeERC20.safeTransferFrom on a pool token
             *
             * @dev Reentrancy safety enforced via `ReentrancyGuard.nonReentrant`
             */
            function transferPoolTokenFrom(
              address _from,
              address _to,
              uint256 _value
            ) internal nonReentrant {
              // just delegate call to the target
              SafeERC20.safeTransferFrom(IERC20(poolToken), _from, _to, _value);
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity 0.8.9;
          /**
           * @title Staking Pool - Fork of Illuvium
           *
           * @notice An abstraction representing a pool, see zStakePoolBase for details
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          interface IPool {
            /**
             * @dev Deposit is a key data structure used in staking,
             *      it represents a unit of stake with its amount, weight and term (time interval)
             */
            struct Deposit {
              // @dev token amount staked
              uint256 tokenAmount;
              // @dev stake weight
              uint256 weight;
              // @dev locking period - from
              uint64 lockedFrom;
              // @dev locking period - until
              uint64 lockedUntil;
              // @dev indicates if the stake was created as a yield reward
              bool isYield;
            }
            function rewardToken() external view returns (address);
            function poolToken() external view returns (address);
            function isFlashPool() external view returns (bool);
            function weight() external view returns (uint32);
            function lastYieldDistribution() external view returns (uint64);
            function yieldRewardsPerWeight() external view returns (uint256);
            function usersLockingWeight() external view returns (uint256);
            function pendingYieldRewards(address _user) external view returns (uint256);
            function balanceOf(address _user) external view returns (uint256);
            function getDeposit(address _user, uint256 _depositId) external view returns (Deposit memory);
            function getDepositsLength(address _user) external view returns (uint256);
            function stake(uint256 _amount, uint64 _lockedUntil) external;
            function unstake(uint256 _depositId, uint256 _amount) external;
            function sync() external;
            function processRewards() external;
            function setWeight(uint32 _weight) external;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity 0.8.9;
          import "./IPool.sol";
          interface ICorePool is IPool {
            function poolTokenReserve() external view returns (uint256);
            function stakeAsPool(address _staker, uint256 _amount) external;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
          /**
           * @dev Contract module that helps prevent reentrant calls to a function.
           *
           * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
           * available, which can be applied to functions to make sure there are no nested
           * (reentrant) calls to them.
           *
           * Note that because there is a single `nonReentrant` guard, functions marked as
           * `nonReentrant` may not call one another. This can be worked around by making
           * those functions `private`, and then adding `external` `nonReentrant` entry
           * points to them.
           *
           * TIP: If you would like to learn more about reentrancy and alternative ways
           * to protect against it, check out our blog post
           * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
           */
          abstract contract ReentrancyGuardUpgradeable is Initializable {
              // Booleans are more expensive than uint256 or any type that takes up a full
              // word because each write operation emits an extra SLOAD to first read the
              // slot's contents, replace the bits taken up by the boolean, and then write
              // back. This is the compiler's defense against contract upgrades and
              // pointer aliasing, and it cannot be disabled.
              // The values being non-zero value makes deployment a bit more expensive,
              // but in exchange the refund on every call to nonReentrant will be lower in
              // amount. Since refunds are capped to a percentage of the total
              // transaction's gas, it is best to keep them low in cases like this one, to
              // increase the likelihood of the full refund coming into effect.
              uint256 private constant _NOT_ENTERED = 1;
              uint256 private constant _ENTERED = 2;
              uint256 private _status;
              function __ReentrancyGuard_init() internal initializer {
                  __ReentrancyGuard_init_unchained();
              }
              function __ReentrancyGuard_init_unchained() internal initializer {
                  _status = _NOT_ENTERED;
              }
              /**
               * @dev Prevents a contract from calling itself, directly or indirectly.
               * Calling a `nonReentrant` function from another `nonReentrant`
               * function is not supported. It is possible to prevent this from happening
               * by making the `nonReentrant` function external, and make it call a
               * `private` function that does the actual work.
               */
              modifier nonReentrant() {
                  // On the first call to nonReentrant, _notEntered will be true
                  require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                  // Any calls to nonReentrant after this point will fail
                  _status = _ENTERED;
                  _;
                  // By storing the original value once again, a refund is triggered (see
                  // https://eips.ethereum.org/EIPS/eip-2200)
                  _status = _NOT_ENTERED;
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "./interfaces/IPool.sol";
          import "./zStakeCorePool.sol";
          import "./utils/Ownable.sol";
          import "./interfaces/IERC20.sol";
          import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
          import {PausableUpgradeable} from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
          /**
           * @title Pool Factory - Fork of Illuvium Pool Factory
           *
           * @notice Pool Factory manages Yield farming pools, provides a single
           *      public interface to access the pools, provides an interface for the pools
           *      to mint yield rewards, access pool-related info, update weights, etc.
           *
           * @notice The factory is authorized (via its owner) to register new pools, change weights
           *      of the existing pools, removing the pools (by changing their weights to zero)
           *
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          contract zStakePoolFactory is OwnableUpgradeable, PausableUpgradeable {
            /// @dev The reward token
            address public rewardToken;
            /// @dev The vault that cointains reward tokens which are to be given as staking rewards.
            address public rewardVault;
            /// @dev Auxiliary data structure used only in getPoolData() view function
            struct PoolData {
              // @dev pool token address (like WILD)
              address poolToken;
              // @dev pool address (like deployed core pool instance)
              address poolAddress;
              // @dev pool weight (200 for WILD pools, 800 for WILD/ETH pools - set during deployment)
              uint32 weight;
              // @dev flash pool flag
              bool isFlashPool;
            }
            /**
             * @dev WILD/block determines yield farming reward base
             *      used by the yield pools controlled by the factory
             */
            uint256 internal rewardTokensPerBlock;
            /**
             * @dev The yield is distributed proportionally to pool weights;
             *      total weight is here to help in determining the proportion
             */
            uint32 public totalWeight;
            /// @dev Maps pool token address (like WILD) -> pool address (like core pool instance)
            mapping(address => address) public pools;
            /// @dev Keeps track of registered pool addresses, maps pool address -> exists flag
            mapping(address => bool) public poolExists;
            /**
             * @dev Fired in createPool() and registerPool()
             *
             * @param _by an address which executed an action
             * @param poolToken pool token address (like WILD)
             * @param poolAddress deployed pool instance address
             * @param weight pool weight
             * @param isFlashPool flag indicating if pool is a flash pool
             */
            event PoolRegistered(
              address indexed _by,
              address indexed poolToken,
              address indexed poolAddress,
              uint64 weight,
              bool isFlashPool
            );
            /**
             * @dev Fired in changePoolWeight()
             *
             * @param _by an address which executed an action
             * @param poolAddress deployed pool instance address
             * @param weight new pool weight
             */
            event WeightUpdated(address indexed _by, address indexed poolAddress, uint32 weight);
            /**
             * @dev Fired in updateWILDPerBlock()
             *
             * @param _by an address which executed an action
             * @param newIlvPerBlock new WILD/block value
             */
            event WildRatioUpdated(address indexed _by, uint256 newIlvPerBlock);
            /**
             * @dev Creates/deploys a factory instance
             *
             * @param _rewardToken WILD ERC20 token address
             * @param _rewardsVault The vault which contains WILD tokens that are staking rewards
             * @param _rewardTokensPerBlock initial WILD/block value for rewards
             */
            function initialize(
              address _rewardToken,
              address _rewardsVault,
              uint192 _rewardTokensPerBlock
            ) public initializer {
              __Ownable_init();
              // verify the inputs are set
              require(_rewardTokensPerBlock > 0, "WILD/block not set");
              // save the inputs into internal state variables
              rewardToken = _rewardToken;
              rewardVault = _rewardsVault;
              rewardTokensPerBlock = _rewardTokensPerBlock;
            }
            // Call this on the implementation contract (not the proxy)
            function initializeImplementation() public initializer {
              __Ownable_init();
              _pause();
            }
            /**
             * @notice Given a pool token retrieves corresponding pool address
             *
             * @dev A shortcut for `pools` mapping
             *
             * @param poolToken pool token address (like WILD) to query pool address for
             * @return pool address for the token specified
             */
            function getPoolAddress(address poolToken) external view returns (address) {
              // read the mapping and return
              return pools[poolToken];
            }
            /**
             * @notice Reads pool information for the pool defined by its pool token address,
             *      designed to simplify integration with the front ends
             *
             * @param _poolToken pool token address to query pool information for
             * @return pool information packed in a PoolData struct
             */
            function getPoolData(address _poolToken) public view returns (PoolData memory) {
              // get the pool address from the mapping
              address poolAddr = pools[_poolToken];
              // throw if there is no pool registered for the token specified
              require(poolAddr != address(0), "pool not found");
              // read pool information from the pool smart contract
              // via the pool interface (IPool)
              address poolToken = IPool(poolAddr).poolToken();
              bool isFlashPool = IPool(poolAddr).isFlashPool();
              uint32 weight = IPool(poolAddr).weight();
              // create the in-memory structure and return it
              return
                PoolData({
                  poolToken: poolToken,
                  poolAddress: poolAddr,
                  weight: weight,
                  isFlashPool: isFlashPool
                });
            }
            /**
             * @dev Registers an already deployed pool instance within the factory
             *
             * @dev Can be executed by the pool factory owner only
             *
             * @param poolAddr address of the already deployed pool instance
             */
            function registerPool(address poolAddr) public onlyOwner {
              require(!paused(), "contract is paused");
              // read pool information from the pool smart contract
              // via the pool interface (IPool)
              address poolToken = IPool(poolAddr).poolToken();
              bool isFlashPool = IPool(poolAddr).isFlashPool();
              uint32 weight = IPool(poolAddr).weight();
              // ensure that the pool is not already registered within the factory
              require(pools[poolToken] == address(0), "this pool is already registered");
              // create pool structure, register it within the factory
              pools[poolToken] = poolAddr;
              poolExists[poolAddr] = true;
              // update total pool weight of the factory
              totalWeight += weight;
              // emit an event
              emit PoolRegistered(msg.sender, poolToken, poolAddr, weight, isFlashPool);
            }
            /**
             * @dev Transfers reward tokens from the rewards vault. Executed by Reward Token Pool only
             *
             * @dev Requires factory to have allowance on rewardVault
             *
             * @param _to an address to mint tokens to
             * @param _amount amount of reward tokens to transfer
             */
            function transferRewardYield(address _to, uint256 _amount) external {
              require(!paused(), "contract is paused");
              // verify that sender is a pool registered withing the factory
              require(poolExists[msg.sender], "access denied");
              // transfer WILD tokens as required
              IERC20(rewardToken).transferFrom(rewardVault, _to, _amount);
            }
            /**
             * @dev Changes the weight of the pool;
             *      executed by the pool itself or by the factory owner
             *
             * @param poolAddr address of the pool to change weight for
             * @param weight new weight value to set to
             */
            function changePoolWeight(address poolAddr, uint32 weight) external {
              require(!paused(), "contract is paused");
              // verify function is executed either by factory owner or by the pool itself
              require(msg.sender == owner() || poolExists[msg.sender]);
              // recalculate total weight
              totalWeight = totalWeight + weight - IPool(poolAddr).weight();
              // set the new pool weight
              IPool(poolAddr).setWeight(weight);
              // emit an event
              emit WeightUpdated(msg.sender, poolAddr, weight);
            }
            /**
             * @dev Changes the amount of wild given per block
             *
             * @param perBlock Amount of wild given per block
             */
            function changeRewardTokensPerBlock(uint256 perBlock) external {
              require(!paused(), "contract is paused");
              require(rewardTokensPerBlock != perBlock, "No change");
              rewardTokensPerBlock = perBlock;
            }
            /**
             * @dev Testing time-dependent functionality is difficult and the best way of
             *      doing it is to override block number in helper test smart contracts
             *
             * @return `block.number` in mainnet, custom values in testnets (if overridden)
             */
            function blockNumber() public view virtual returns (uint256) {
              // return current block number
              return block.number;
            }
            /**
             * @dev Returns amount of tokens to be given per block, may be upgraded in the future
             *
             * @return Amount of reward tokens to reward per block
             */
            function getRewardTokensPerBlock() public view returns (uint256) {
              return rewardTokensPerBlock;
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "../interfaces/IERC20.sol";
          import "./AddressUpgradeable.sol";
          /**
           * @title SafeERC20
           * @dev Wrappers around ERC20 operations that throw on failure (when the token
           * contract returns false). Tokens that return no value (and instead revert or
           * throw on failure) are also supported, non-reverting calls are assumed to be
           * successful.
           * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
           * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
           */
          library SafeERC20 {
            using AddressUpgradeable for address;
            function safeTransfer(
              IERC20 token,
              address to,
              uint256 value
            ) internal {
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.transfer.selector, to, value)
              );
            }
            function safeTransferFrom(
              IERC20 token,
              address from,
              address to,
              uint256 value
            ) internal {
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
              );
            }
            /**
             * @dev Deprecated. This function has issues similar to the ones found in
             * {IERC20-approve}, and its usage is discouraged.
             *
             * Whenever possible, use {safeIncreaseAllowance} and
             * {safeDecreaseAllowance} instead.
             */
            function safeApprove(
              IERC20 token,
              address spender,
              uint256 value
            ) internal {
              // safeApprove should only be called when setting an initial allowance,
              // or when resetting it to zero. To increase and decrease it, use
              // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
              // solhint-disable-next-line max-line-length
              require(
                (value == 0) || (token.allowance(address(this), spender) == 0),
                "SafeERC20: approve from non-zero to non-zero allowance"
              );
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.approve.selector, spender, value)
              );
            }
            function safeIncreaseAllowance(
              IERC20 token,
              address spender,
              uint256 value
            ) internal {
              uint256 newAllowance = token.allowance(address(this), spender) + value;
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
              );
            }
            function safeDecreaseAllowance(
              IERC20 token,
              address spender,
              uint256 value
            ) internal {
              uint256 newAllowance = token.allowance(address(this), spender) - value;
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
              );
            }
            /**
             * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
             * on the return value: the return value is optional (but if data is returned, it must not be false).
             * @param token The token targeted by the call.
             * @param data The call data (encoded using abi.encode or one of its variants).
             */
            function _callOptionalReturn(IERC20 token, bytes memory data) private {
              // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
              // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
              // the target address contains contract code and also asserts for success in the low-level call.
              bytes memory returndata = address(token).functionCall(
                data,
                "SafeERC20: low-level call failed"
              );
              if (returndata.length > 0) {
                // Return data is optional
                // solhint-disable-next-line max-line-length
                require(
                  abi.decode(returndata, (bool)),
                  "SafeERC20: ERC20 operation did not succeed"
                );
              }
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/ContextUpgradeable.sol";
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module which allows children to implement an emergency stop
           * mechanism that can be triggered by an authorized account.
           *
           * This module is used through inheritance. It will make available the
           * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
           * the functions of your contract. Note that they will not be pausable by
           * simply including this module, only once the modifiers are put in place.
           */
          abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
              /**
               * @dev Emitted when the pause is triggered by `account`.
               */
              event Paused(address account);
              /**
               * @dev Emitted when the pause is lifted by `account`.
               */
              event Unpaused(address account);
              bool private _paused;
              /**
               * @dev Initializes the contract in unpaused state.
               */
              function __Pausable_init() internal initializer {
                  __Context_init_unchained();
                  __Pausable_init_unchained();
              }
              function __Pausable_init_unchained() internal initializer {
                  _paused = false;
              }
              /**
               * @dev Returns true if the contract is paused, and false otherwise.
               */
              function paused() public view virtual returns (bool) {
                  return _paused;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is not paused.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              modifier whenNotPaused() {
                  require(!paused(), "Pausable: paused");
                  _;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is paused.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              modifier whenPaused() {
                  require(paused(), "Pausable: not paused");
                  _;
              }
              /**
               * @dev Triggers stopped state.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              function _pause() internal virtual whenNotPaused {
                  _paused = true;
                  emit Paused(_msgSender());
              }
              /**
               * @dev Returns to normal state.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              function _unpause() internal virtual whenPaused {
                  _paused = false;
                  emit Unpaused(_msgSender());
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
           * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
           * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
           * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
           *
           * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
           * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
           *
           * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
           * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
           */
          abstract contract Initializable {
              /**
               * @dev Indicates that the contract has been initialized.
               */
              bool private _initialized;
              /**
               * @dev Indicates that the contract is in the process of being initialized.
               */
              bool private _initializing;
              /**
               * @dev Modifier to protect an initializer function from being invoked twice.
               */
              modifier initializer() {
                  require(_initializing || !_initialized, "Initializable: contract is already initialized");
                  bool isTopLevelCall = !_initializing;
                  if (isTopLevelCall) {
                      _initializing = true;
                      _initialized = true;
                  }
                  _;
                  if (isTopLevelCall) {
                      _initializing = false;
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable {
            address private _owner;
            event OwnershipTransferred(
              address indexed previousOwner,
              address indexed newOwner
            );
            /**
             * @dev Initializes the contract setting the deployer as the initial owner.
             */
            constructor() {
              address msgSender = msg.sender;
              _owner = msgSender;
              emit OwnershipTransferred(address(0), msgSender);
            }
            /**
             * @dev Returns the address of the current owner.
             */
            function owner() public view virtual returns (address) {
              return _owner;
            }
            /**
             * @dev Throws if called by any account other than the owner.
             */
            modifier onlyOwner() {
              require(owner() == msg.sender, "Ownable: caller is not the owner");
              _;
            }
            /**
             * @dev Leaves the contract without owner. It will not be possible to call
             * `onlyOwner` functions anymore. Can only be called by the current owner.
             *
             * NOTE: Renouncing ownership will leave the contract without an owner,
             * thereby removing any functionality that is only available to the owner.
             */
            function renounceOwnership() public virtual onlyOwner {
              emit OwnershipTransferred(_owner, address(0));
              _owner = address(0);
            }
            /**
             * @dev Transfers ownership of the contract to a new account (`newOwner`).
             * Can only be called by the current owner.
             */
            function transferOwnership(address newOwner) public virtual onlyOwner {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              emit OwnershipTransferred(_owner, newOwner);
              _owner = newOwner;
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity 0.8.9;
          /**
           * @dev Interface of the ERC20 standard as defined in the EIP.
           */
          interface IERC20 {
            /**
             * @dev Returns the amount of tokens in existence.
             */
            function totalSupply() external view returns (uint256);
            /**
             * @dev Returns the amount of tokens owned by `account`.
             */
            function balanceOf(address account) external view returns (uint256);
            /**
             * @dev Moves `amount` tokens from the caller's account to `recipient`.
             *
             * Returns a boolean value indicating whether the operation succeeded.
             *
             * Emits a {Transfer} event.
             */
            function transfer(address recipient, uint256 amount) external returns (bool);
            /**
             * @dev Returns the remaining number of tokens that `spender` will be
             * allowed to spend on behalf of `owner` through {transferFrom}. This is
             * zero by default.
             *
             * This value changes when {approve} or {transferFrom} are called.
             */
            function allowance(address owner, address spender)
              external
              view
              returns (uint256);
            /**
             * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
             *
             * Returns a boolean value indicating whether the operation succeeded.
             *
             * IMPORTANT: Beware that changing an allowance with this method brings the risk
             * that someone may use both the old and the new allowance by unfortunate
             * transaction ordering. One possible solution to mitigate this race
             * condition is to first reduce the spender's allowance to 0 and set the
             * desired value afterwards:
             * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
             *
             * Emits an {Approval} event.
             */
            function approve(address spender, uint256 amount) external returns (bool);
            /**
             * @dev Moves `amount` tokens from `sender` to `recipient` using the
             * allowance mechanism. `amount` is then deducted from the caller's
             * allowance.
             *
             * Returns a boolean value indicating whether the operation succeeded.
             *
             * Emits a {Transfer} event.
             */
            function transferFrom(
              address sender,
              address recipient,
              uint256 amount
            ) external returns (bool);
            /**
             * @dev Emitted when `value` tokens are moved from one account (`from`) to
             * another (`to`).
             *
             * Note that `value` may be zero.
             */
            event Transfer(address indexed from, address indexed to, uint256 value);
            /**
             * @dev Emitted when the allowance of a `spender` for an `owner` is set by
             * a call to {approve}. `value` is the new allowance.
             */
            event Approval(address indexed owner, address indexed spender, uint256 value);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/ContextUpgradeable.sol";
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              function __Ownable_init() internal initializer {
                  __Context_init_unchained();
                  __Ownable_init_unchained();
              }
              function __Ownable_init_unchained() internal initializer {
                  _setOwner(_msgSender());
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  _setOwner(address(0));
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  _setOwner(newOwner);
              }
              function _setOwner(address newOwner) private {
                  address oldOwner = _owner;
                  _owner = newOwner;
                  emit OwnershipTransferred(oldOwner, newOwner);
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract ContextUpgradeable is Initializable {
              function __Context_init() internal initializer {
                  __Context_init_unchained();
              }
              function __Context_init_unchained() internal initializer {
              }
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  return msg.data;
              }
              uint256[50] private __gap;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.0 (utils/Address.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Collection of functions related to the address type
           */
          library AddressUpgradeable {
              /**
               * @dev Returns true if `account` is a contract.
               *
               * [IMPORTANT]
               * ====
               * It is unsafe to assume that an address for which this function returns
               * false is an externally-owned account (EOA) and not a contract.
               *
               * Among others, `isContract` will return false for the following
               * types of addresses:
               *
               *  - an externally-owned account
               *  - a contract in construction
               *  - an address where a contract will be created
               *  - an address where a contract lived, but was destroyed
               * ====
               */
              function isContract(address account) internal view returns (bool) {
                  // This method relies on extcodesize, which returns 0 for contracts in
                  // construction, since the code is only stored at the end of the
                  // constructor execution.
                  uint256 size;
                  assembly {
                      size := extcodesize(account)
                  }
                  return size > 0;
              }
              /**
               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
               * `recipient`, forwarding all available gas and reverting on errors.
               *
               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
               * of certain opcodes, possibly making contracts go over the 2300 gas limit
               * imposed by `transfer`, making them unable to receive funds via
               * `transfer`. {sendValue} removes this limitation.
               *
               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
               *
               * IMPORTANT: because control is transferred to `recipient`, care must be
               * taken to not create reentrancy vulnerabilities. Consider using
               * {ReentrancyGuard} or the
               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
               */
              function sendValue(address payable recipient, uint256 amount) internal {
                  require(address(this).balance >= amount, "Address: insufficient balance");
                  (bool success, ) = recipient.call{value: amount}("");
                  require(success, "Address: unable to send value, recipient may have reverted");
              }
              /**
               * @dev Performs a Solidity function call using a low level `call`. A
               * plain `call` is an unsafe replacement for a function call: use this
               * function instead.
               *
               * If `target` reverts with a revert reason, it is bubbled up by this
               * function (like regular Solidity function calls).
               *
               * Returns the raw returned data. To convert to the expected return value,
               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
               *
               * Requirements:
               *
               * - `target` must be a contract.
               * - calling `target` with `data` must not revert.
               *
               * _Available since v3.1._
               */
              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                  return functionCall(target, data, "Address: low-level call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
               * `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCall(
                  address target,
                  bytes memory data,
                  string memory errorMessage
              ) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, 0, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but also transferring `value` wei to `target`.
               *
               * Requirements:
               *
               * - the calling contract must have an ETH balance of at least `value`.
               * - the called Solidity function must be `payable`.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(
                  address target,
                  bytes memory data,
                  uint256 value
              ) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
              }
              /**
               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
               * with `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(
                  address target,
                  bytes memory data,
                  uint256 value,
                  string memory errorMessage
              ) internal returns (bytes memory) {
                  require(address(this).balance >= value, "Address: insufficient balance for call");
                  require(isContract(target), "Address: call to non-contract");
                  (bool success, bytes memory returndata) = target.call{value: value}(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                  return functionStaticCall(target, data, "Address: low-level static call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(
                  address target,
                  bytes memory data,
                  string memory errorMessage
              ) internal view returns (bytes memory) {
                  require(isContract(target), "Address: static call to non-contract");
                  (bool success, bytes memory returndata) = target.staticcall(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
               * revert reason using the provided one.
               *
               * _Available since v4.3._
               */
              function verifyCallResult(
                  bool success,
                  bytes memory returndata,
                  string memory errorMessage
              ) internal pure returns (bytes memory) {
                  if (success) {
                      return returndata;
                  } else {
                      // Look for revert reason and bubble it up if present
                      if (returndata.length > 0) {
                          // The easiest way to bubble the revert reason is using memory via assembly
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }

          File 3 of 4: TransparentUpgradeableProxy
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
          import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
          import "@openzeppelin/contracts/proxy/transparent/ProxyAdmin.sol";
          // Kept for backwards compatibility with older versions of Hardhat and Truffle plugins.
          contract AdminUpgradeabilityProxy is TransparentUpgradeableProxy {
              constructor(address logic, address admin, bytes memory data) payable TransparentUpgradeableProxy(logic, admin, data) {}
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../Proxy.sol";
          import "./ERC1967Upgrade.sol";
          /**
           * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
           * implementation address that can be changed. This address is stored in storage in the location specified by
           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
           * implementation behind the proxy.
           */
          contract ERC1967Proxy is Proxy, ERC1967Upgrade {
              /**
               * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
               *
               * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
               * function call, and allows initializating the storage of the proxy like a Solidity constructor.
               */
              constructor(address _logic, bytes memory _data) payable {
                  assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                  _upgradeToAndCall(_logic, _data, false);
              }
              /**
               * @dev Returns the current implementation address.
               */
              function _implementation() internal view virtual override returns (address impl) {
                  return ERC1967Upgrade._getImplementation();
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../ERC1967/ERC1967Proxy.sol";
          /**
           * @dev This contract implements a proxy that is upgradeable by an admin.
           *
           * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
           * clashing], which can potentially be used in an attack, this contract uses the
           * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
           * things that go hand in hand:
           *
           * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
           * that call matches one of the admin functions exposed by the proxy itself.
           * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
           * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
           * "admin cannot fallback to proxy target".
           *
           * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
           * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
           * to sudden errors when trying to call a function from the proxy implementation.
           *
           * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
           * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
           */
          contract TransparentUpgradeableProxy is ERC1967Proxy {
              /**
               * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
               * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
               */
              constructor(address _logic, address admin_, bytes memory _data) payable ERC1967Proxy(_logic, _data) {
                  assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
                  _changeAdmin(admin_);
              }
              /**
               * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
               */
              modifier ifAdmin() {
                  if (msg.sender == _getAdmin()) {
                      _;
                  } else {
                      _fallback();
                  }
              }
              /**
               * @dev Returns the current admin.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
               *
               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
               * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
               */
              function admin() external ifAdmin returns (address admin_) {
                  admin_ = _getAdmin();
              }
              /**
               * @dev Returns the current implementation.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
               *
               * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
               * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
               * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
               */
              function implementation() external ifAdmin returns (address implementation_) {
                  implementation_ = _implementation();
              }
              /**
               * @dev Changes the admin of the proxy.
               *
               * Emits an {AdminChanged} event.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
               */
              function changeAdmin(address newAdmin) external virtual ifAdmin {
                  _changeAdmin(newAdmin);
              }
              /**
               * @dev Upgrade the implementation of the proxy.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
               */
              function upgradeTo(address newImplementation) external ifAdmin {
                  _upgradeToAndCall(newImplementation, bytes(""), false);
              }
              /**
               * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
               * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
               * proxied contract.
               *
               * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
               */
              function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
                  _upgradeToAndCall(newImplementation, data, true);
              }
              /**
               * @dev Returns the current admin.
               */
              function _admin() internal view virtual returns (address) {
                  return _getAdmin();
              }
              /**
               * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
               */
              function _beforeFallback() internal virtual override {
                  require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
                  super._beforeFallback();
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "./TransparentUpgradeableProxy.sol";
          import "../../access/Ownable.sol";
          /**
           * @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
           * explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
           */
          contract ProxyAdmin is Ownable {
              /**
               * @dev Returns the current implementation of `proxy`.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function getProxyImplementation(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
                  // We need to manually run the static call since the getter cannot be flagged as view
                  // bytes4(keccak256("implementation()")) == 0x5c60da1b
                  (bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
                  require(success);
                  return abi.decode(returndata, (address));
              }
              /**
               * @dev Returns the current admin of `proxy`.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function getProxyAdmin(TransparentUpgradeableProxy proxy) public view virtual returns (address) {
                  // We need to manually run the static call since the getter cannot be flagged as view
                  // bytes4(keccak256("admin()")) == 0xf851a440
                  (bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
                  require(success);
                  return abi.decode(returndata, (address));
              }
              /**
               * @dev Changes the admin of `proxy` to `newAdmin`.
               *
               * Requirements:
               *
               * - This contract must be the current admin of `proxy`.
               */
              function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
                  proxy.changeAdmin(newAdmin);
              }
              /**
               * @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function upgrade(TransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
                  proxy.upgradeTo(implementation);
              }
              /**
               * @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
               * {TransparentUpgradeableProxy-upgradeToAndCall}.
               *
               * Requirements:
               *
               * - This contract must be the admin of `proxy`.
               */
              function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable virtual onlyOwner {
                  proxy.upgradeToAndCall{value: msg.value}(implementation, data);
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
           * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
           * be specified by overriding the virtual {_implementation} function.
           *
           * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
           * different contract through the {_delegate} function.
           *
           * The success and return data of the delegated call will be returned back to the caller of the proxy.
           */
          abstract contract Proxy {
              /**
               * @dev Delegates the current call to `implementation`.
               *
               * This function does not return to its internall call site, it will return directly to the external caller.
               */
              function _delegate(address implementation) internal virtual {
                  // solhint-disable-next-line no-inline-assembly
                  assembly {
                      // Copy msg.data. We take full control of memory in this inline assembly
                      // block because it will not return to Solidity code. We overwrite the
                      // Solidity scratch pad at memory position 0.
                      calldatacopy(0, 0, calldatasize())
                      // Call the implementation.
                      // out and outsize are 0 because we don't know the size yet.
                      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                      // Copy the returned data.
                      returndatacopy(0, 0, returndatasize())
                      switch result
                      // delegatecall returns 0 on error.
                      case 0 { revert(0, returndatasize()) }
                      default { return(0, returndatasize()) }
                  }
              }
              /**
               * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
               * and {_fallback} should delegate.
               */
              function _implementation() internal view virtual returns (address);
              /**
               * @dev Delegates the current call to the address returned by `_implementation()`.
               *
               * This function does not return to its internall call site, it will return directly to the external caller.
               */
              function _fallback() internal virtual {
                  _beforeFallback();
                  _delegate(_implementation());
              }
              /**
               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
               * function in the contract matches the call data.
               */
              fallback () external payable virtual {
                  _fallback();
              }
              /**
               * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
               * is empty.
               */
              receive () external payable virtual {
                  _fallback();
              }
              /**
               * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
               * call, or as part of the Solidity `fallback` or `receive` functions.
               *
               * If overriden should call `super._beforeFallback()`.
               */
              function _beforeFallback() internal virtual {
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.2;
          import "../beacon/IBeacon.sol";
          import "../../utils/Address.sol";
          import "../../utils/StorageSlot.sol";
          /**
           * @dev This abstract contract provides getters and event emitting update functions for
           * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
           *
           * _Available since v4.1._
           *
           * @custom:oz-upgrades-unsafe-allow delegatecall
           */
          abstract contract ERC1967Upgrade {
              // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
              bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
              /**
               * @dev Storage slot with the address of the current implementation.
               * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
               * validated in the constructor.
               */
              bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
              /**
               * @dev Emitted when the implementation is upgraded.
               */
              event Upgraded(address indexed implementation);
              /**
               * @dev Returns the current implementation address.
               */
              function _getImplementation() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
              }
              /**
               * @dev Stores a new address in the EIP1967 implementation slot.
               */
              function _setImplementation(address newImplementation) private {
                  require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                  StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
              }
              /**
               * @dev Perform implementation upgrade
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeTo(address newImplementation) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
              }
              /**
               * @dev Perform implementation upgrade with additional setup call.
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
                  _setImplementation(newImplementation);
                  emit Upgraded(newImplementation);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(newImplementation, data);
                  }
              }
              /**
               * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
               *
               * Emits an {Upgraded} event.
               */
              function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
                  address oldImplementation = _getImplementation();
                  // Initial upgrade and setup call
                  _setImplementation(newImplementation);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(newImplementation, data);
                  }
                  // Perform rollback test if not already in progress
                  StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                  if (!rollbackTesting.value) {
                      // Trigger rollback using upgradeTo from the new implementation
                      rollbackTesting.value = true;
                      Address.functionDelegateCall(
                          newImplementation,
                          abi.encodeWithSignature(
                              "upgradeTo(address)",
                              oldImplementation
                          )
                      );
                      rollbackTesting.value = false;
                      // Check rollback was effective
                      require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                      // Finally reset to the new implementation and log the upgrade
                      _setImplementation(newImplementation);
                      emit Upgraded(newImplementation);
                  }
              }
              /**
               * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
               * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
               *
               * Emits a {BeaconUpgraded} event.
               */
              function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
                  _setBeacon(newBeacon);
                  emit BeaconUpgraded(newBeacon);
                  if (data.length > 0 || forceCall) {
                      Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                  }
              }
              /**
               * @dev Storage slot with the admin of the contract.
               * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
               * validated in the constructor.
               */
              bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
              /**
               * @dev Emitted when the admin account has changed.
               */
              event AdminChanged(address previousAdmin, address newAdmin);
              /**
               * @dev Returns the current admin.
               */
              function _getAdmin() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
              }
              /**
               * @dev Stores a new address in the EIP1967 admin slot.
               */
              function _setAdmin(address newAdmin) private {
                  require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                  StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
              }
              /**
               * @dev Changes the admin of the proxy.
               *
               * Emits an {AdminChanged} event.
               */
              function _changeAdmin(address newAdmin) internal {
                  emit AdminChanged(_getAdmin(), newAdmin);
                  _setAdmin(newAdmin);
              }
              /**
               * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
               * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
               */
              bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
              /**
               * @dev Emitted when the beacon is upgraded.
               */
              event BeaconUpgraded(address indexed beacon);
              /**
               * @dev Returns the current beacon.
               */
              function _getBeacon() internal view returns (address) {
                  return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
              }
              /**
               * @dev Stores a new beacon in the EIP1967 beacon slot.
               */
              function _setBeacon(address newBeacon) private {
                  require(
                      Address.isContract(newBeacon),
                      "ERC1967: new beacon is not a contract"
                  );
                  require(
                      Address.isContract(IBeacon(newBeacon).implementation()),
                      "ERC1967: beacon implementation is not a contract"
                  );
                  StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This is the interface that {BeaconProxy} expects of its beacon.
           */
          interface IBeacon {
              /**
               * @dev Must return an address that can be used as a delegate call target.
               *
               * {BeaconProxy} will check that this address is a contract.
               */
              function implementation() external view returns (address);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev Collection of functions related to the address type
           */
          library Address {
              /**
               * @dev Returns true if `account` is a contract.
               *
               * [IMPORTANT]
               * ====
               * It is unsafe to assume that an address for which this function returns
               * false is an externally-owned account (EOA) and not a contract.
               *
               * Among others, `isContract` will return false for the following
               * types of addresses:
               *
               *  - an externally-owned account
               *  - a contract in construction
               *  - an address where a contract will be created
               *  - an address where a contract lived, but was destroyed
               * ====
               */
              function isContract(address account) internal view returns (bool) {
                  // This method relies on extcodesize, which returns 0 for contracts in
                  // construction, since the code is only stored at the end of the
                  // constructor execution.
                  uint256 size;
                  // solhint-disable-next-line no-inline-assembly
                  assembly { size := extcodesize(account) }
                  return size > 0;
              }
              /**
               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
               * `recipient`, forwarding all available gas and reverting on errors.
               *
               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
               * of certain opcodes, possibly making contracts go over the 2300 gas limit
               * imposed by `transfer`, making them unable to receive funds via
               * `transfer`. {sendValue} removes this limitation.
               *
               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
               *
               * IMPORTANT: because control is transferred to `recipient`, care must be
               * taken to not create reentrancy vulnerabilities. Consider using
               * {ReentrancyGuard} or the
               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
               */
              function sendValue(address payable recipient, uint256 amount) internal {
                  require(address(this).balance >= amount, "Address: insufficient balance");
                  // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                  (bool success, ) = recipient.call{ value: amount }("");
                  require(success, "Address: unable to send value, recipient may have reverted");
              }
              /**
               * @dev Performs a Solidity function call using a low level `call`. A
               * plain`call` is an unsafe replacement for a function call: use this
               * function instead.
               *
               * If `target` reverts with a revert reason, it is bubbled up by this
               * function (like regular Solidity function calls).
               *
               * Returns the raw returned data. To convert to the expected return value,
               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
               *
               * Requirements:
               *
               * - `target` must be a contract.
               * - calling `target` with `data` must not revert.
               *
               * _Available since v3.1._
               */
              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                return functionCall(target, data, "Address: low-level call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
               * `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, 0, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but also transferring `value` wei to `target`.
               *
               * Requirements:
               *
               * - the calling contract must have an ETH balance of at least `value`.
               * - the called Solidity function must be `payable`.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
              }
              /**
               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
               * with `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                  require(address(this).balance >= value, "Address: insufficient balance for call");
                  require(isContract(target), "Address: call to non-contract");
                  // solhint-disable-next-line avoid-low-level-calls
                  (bool success, bytes memory returndata) = target.call{ value: value }(data);
                  return _verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                  return functionStaticCall(target, data, "Address: low-level static call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                  require(isContract(target), "Address: static call to non-contract");
                  // solhint-disable-next-line avoid-low-level-calls
                  (bool success, bytes memory returndata) = target.staticcall(data);
                  return _verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but performing a delegate call.
               *
               * _Available since v3.4._
               */
              function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                  return functionDelegateCall(target, data, "Address: low-level delegate call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
               * but performing a delegate call.
               *
               * _Available since v3.4._
               */
              function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                  require(isContract(target), "Address: delegate call to non-contract");
                  // solhint-disable-next-line avoid-low-level-calls
                  (bool success, bytes memory returndata) = target.delegatecall(data);
                  return _verifyCallResult(success, returndata, errorMessage);
              }
              function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                  if (success) {
                      return returndata;
                  } else {
                      // Look for revert reason and bubble it up if present
                      if (returndata.length > 0) {
                          // The easiest way to bubble the revert reason is using memory via assembly
                          // solhint-disable-next-line no-inline-assembly
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev Library for reading and writing primitive types to specific storage slots.
           *
           * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
           * This library helps with reading and writing to such slots without the need for inline assembly.
           *
           * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
           *
           * Example usage to set ERC1967 implementation slot:
           * ```
           * contract ERC1967 {
           *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
           *
           *     function _getImplementation() internal view returns (address) {
           *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
           *     }
           *
           *     function _setImplementation(address newImplementation) internal {
           *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
           *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
           *     }
           * }
           * ```
           *
           * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
           */
          library StorageSlot {
              struct AddressSlot {
                  address value;
              }
              struct BooleanSlot {
                  bool value;
              }
              struct Bytes32Slot {
                  bytes32 value;
              }
              struct Uint256Slot {
                  uint256 value;
              }
              /**
               * @dev Returns an `AddressSlot` with member `value` located at `slot`.
               */
              function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
               */
              function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
               */
              function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
              /**
               * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
               */
              function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                  assembly {
                      r.slot := slot
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/Context.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable is Context {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              constructor () {
                  address msgSender = _msgSender();
                  _owner = msgSender;
                  emit OwnershipTransferred(address(0), msgSender);
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  emit OwnershipTransferred(_owner, address(0));
                  _owner = address(0);
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  emit OwnershipTransferred(_owner, newOwner);
                  _owner = newOwner;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /*
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract Context {
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                  return msg.data;
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../ERC1967/ERC1967Upgrade.sol";
          /**
           * @dev Base contract for building openzeppelin-upgrades compatible implementations for the {ERC1967Proxy}. It includes
           * publicly available upgrade functions that are called by the plugin and by the secure upgrade mechanism to verify
           * continuation of the upgradability.
           *
           * The {_authorizeUpgrade} function MUST be overridden to include access restriction to the upgrade mechanism.
           *
           * _Available since v4.1._
           */
          abstract contract UUPSUpgradeable is ERC1967Upgrade {
              function upgradeTo(address newImplementation) external virtual {
                  _authorizeUpgrade(newImplementation);
                  _upgradeToAndCallSecure(newImplementation, bytes(""), false);
              }
              function upgradeToAndCall(address newImplementation, bytes memory data) external payable virtual {
                  _authorizeUpgrade(newImplementation);
                  _upgradeToAndCallSecure(newImplementation, data, true);
              }
              function _authorizeUpgrade(address newImplementation) internal virtual;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.2;
          import "@openzeppelin/contracts/proxy/utils/UUPSUpgradeable.sol";
          abstract contract Proxiable is UUPSUpgradeable {
              function _authorizeUpgrade(address newImplementation) internal override {
                  _beforeUpgrade(newImplementation);
              }
              function _beforeUpgrade(address newImplementation) internal virtual;
          }
          contract ChildOfProxiable is Proxiable {
              function _beforeUpgrade(address newImplementation) internal virtual override {}
          }
          

          File 4 of 4: zStakePoolFactory
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "./interfaces/IPool.sol";
          import "./zStakeCorePool.sol";
          import "./utils/Ownable.sol";
          import "./interfaces/IERC20.sol";
          import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
          import {PausableUpgradeable} from "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
          /**
           * @title Pool Factory - Fork of Illuvium Pool Factory
           *
           * @notice Pool Factory manages Yield farming pools, provides a single
           *      public interface to access the pools, provides an interface for the pools
           *      to mint yield rewards, access pool-related info, update weights, etc.
           *
           * @notice The factory is authorized (via its owner) to register new pools, change weights
           *      of the existing pools, removing the pools (by changing their weights to zero)
           *
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          contract zStakePoolFactory is OwnableUpgradeable, PausableUpgradeable {
            /// @dev The reward token
            address public rewardToken;
            /// @dev The vault that cointains reward tokens which are to be given as staking rewards.
            address public rewardVault;
            /// @dev Auxiliary data structure used only in getPoolData() view function
            struct PoolData {
              // @dev pool token address (like WILD)
              address poolToken;
              // @dev pool address (like deployed core pool instance)
              address poolAddress;
              // @dev pool weight (200 for WILD pools, 800 for WILD/ETH pools - set during deployment)
              uint32 weight;
              // @dev flash pool flag
              bool isFlashPool;
            }
            /**
             * @dev WILD/block determines yield farming reward base
             *      used by the yield pools controlled by the factory
             */
            uint256 internal rewardTokensPerBlock;
            /**
             * @dev The yield is distributed proportionally to pool weights;
             *      total weight is here to help in determining the proportion
             */
            uint32 public totalWeight;
            /// @dev Maps pool token address (like WILD) -> pool address (like core pool instance)
            mapping(address => address) public pools;
            /// @dev Keeps track of registered pool addresses, maps pool address -> exists flag
            mapping(address => bool) public poolExists;
            /**
             * @dev Fired in createPool() and registerPool()
             *
             * @param _by an address which executed an action
             * @param poolToken pool token address (like WILD)
             * @param poolAddress deployed pool instance address
             * @param weight pool weight
             * @param isFlashPool flag indicating if pool is a flash pool
             */
            event PoolRegistered(
              address indexed _by,
              address indexed poolToken,
              address indexed poolAddress,
              uint64 weight,
              bool isFlashPool
            );
            /**
             * @dev Fired in changePoolWeight()
             *
             * @param _by an address which executed an action
             * @param poolAddress deployed pool instance address
             * @param weight new pool weight
             */
            event WeightUpdated(address indexed _by, address indexed poolAddress, uint32 weight);
            /**
             * @dev Fired in updateWILDPerBlock()
             *
             * @param _by an address which executed an action
             * @param newIlvPerBlock new WILD/block value
             */
            event WildRatioUpdated(address indexed _by, uint256 newIlvPerBlock);
            /**
             * @dev Creates/deploys a factory instance
             *
             * @param _rewardToken WILD ERC20 token address
             * @param _rewardsVault The vault which contains WILD tokens that are staking rewards
             * @param _rewardTokensPerBlock initial WILD/block value for rewards
             */
            function initialize(
              address _rewardToken,
              address _rewardsVault,
              uint192 _rewardTokensPerBlock
            ) public initializer {
              __Ownable_init();
              // verify the inputs are set
              require(_rewardTokensPerBlock > 0, "WILD/block not set");
              // save the inputs into internal state variables
              rewardToken = _rewardToken;
              rewardVault = _rewardsVault;
              rewardTokensPerBlock = _rewardTokensPerBlock;
            }
            // Call this on the implementation contract (not the proxy)
            function initializeImplementation() public initializer {
              __Ownable_init();
              _pause();
            }
            /**
             * @notice Given a pool token retrieves corresponding pool address
             *
             * @dev A shortcut for `pools` mapping
             *
             * @param poolToken pool token address (like WILD) to query pool address for
             * @return pool address for the token specified
             */
            function getPoolAddress(address poolToken) external view returns (address) {
              // read the mapping and return
              return pools[poolToken];
            }
            /**
             * @notice Reads pool information for the pool defined by its pool token address,
             *      designed to simplify integration with the front ends
             *
             * @param _poolToken pool token address to query pool information for
             * @return pool information packed in a PoolData struct
             */
            function getPoolData(address _poolToken) public view returns (PoolData memory) {
              // get the pool address from the mapping
              address poolAddr = pools[_poolToken];
              // throw if there is no pool registered for the token specified
              require(poolAddr != address(0), "pool not found");
              // read pool information from the pool smart contract
              // via the pool interface (IPool)
              address poolToken = IPool(poolAddr).poolToken();
              bool isFlashPool = IPool(poolAddr).isFlashPool();
              uint32 weight = IPool(poolAddr).weight();
              // create the in-memory structure and return it
              return
                PoolData({
                  poolToken: poolToken,
                  poolAddress: poolAddr,
                  weight: weight,
                  isFlashPool: isFlashPool
                });
            }
            /**
             * @dev Registers an already deployed pool instance within the factory
             *
             * @dev Can be executed by the pool factory owner only
             *
             * @param poolAddr address of the already deployed pool instance
             */
            function registerPool(address poolAddr) public onlyOwner {
              require(!paused(), "contract is paused");
              // read pool information from the pool smart contract
              // via the pool interface (IPool)
              address poolToken = IPool(poolAddr).poolToken();
              bool isFlashPool = IPool(poolAddr).isFlashPool();
              uint32 weight = IPool(poolAddr).weight();
              // ensure that the pool is not already registered within the factory
              require(pools[poolToken] == address(0), "this pool is already registered");
              // create pool structure, register it within the factory
              pools[poolToken] = poolAddr;
              poolExists[poolAddr] = true;
              // update total pool weight of the factory
              totalWeight += weight;
              // emit an event
              emit PoolRegistered(msg.sender, poolToken, poolAddr, weight, isFlashPool);
            }
            /**
             * @dev Transfers reward tokens from the rewards vault. Executed by Reward Token Pool only
             *
             * @dev Requires factory to have allowance on rewardVault
             *
             * @param _to an address to mint tokens to
             * @param _amount amount of reward tokens to transfer
             */
            function transferRewardYield(address _to, uint256 _amount) external {
              require(!paused(), "contract is paused");
              // verify that sender is a pool registered withing the factory
              require(poolExists[msg.sender], "access denied");
              // transfer WILD tokens as required
              IERC20(rewardToken).transferFrom(rewardVault, _to, _amount);
            }
            /**
             * @dev Changes the weight of the pool;
             *      executed by the pool itself or by the factory owner
             *
             * @param poolAddr address of the pool to change weight for
             * @param weight new weight value to set to
             */
            function changePoolWeight(address poolAddr, uint32 weight) external {
              require(!paused(), "contract is paused");
              // verify function is executed either by factory owner or by the pool itself
              require(msg.sender == owner() || poolExists[msg.sender]);
              // recalculate total weight
              totalWeight = totalWeight + weight - IPool(poolAddr).weight();
              // set the new pool weight
              IPool(poolAddr).setWeight(weight);
              // emit an event
              emit WeightUpdated(msg.sender, poolAddr, weight);
            }
            /**
             * @dev Changes the amount of wild given per block
             *
             * @param perBlock Amount of wild given per block
             */
            function changeRewardTokensPerBlock(uint256 perBlock) external onlyOwner {
              require(!paused(), "contract is paused");
              require(rewardTokensPerBlock != perBlock, "No change");
              rewardTokensPerBlock = perBlock;
            }
            /**
             * @dev Testing time-dependent functionality is difficult and the best way of
             *      doing it is to override block number in helper test smart contracts
             *
             * @return `block.number` in mainnet, custom values in testnets (if overridden)
             */
            function blockNumber() public view virtual returns (uint256) {
              // return current block number
              return block.number;
            }
            /**
             * @dev Returns amount of tokens to be given per block, may be upgraded in the future
             *
             * @return Amount of reward tokens to reward per block
             */
            function getRewardTokensPerBlock() public view returns (uint256) {
              return rewardTokensPerBlock;
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity 0.8.9;
          /**
           * @title Staking Pool - Fork of Illuvium
           *
           * @notice An abstraction representing a pool, see zStakePoolBase for details
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          interface IPool {
            /**
             * @dev Deposit is a key data structure used in staking,
             *      it represents a unit of stake with its amount, weight and term (time interval)
             */
            struct Deposit {
              // @dev token amount staked
              uint256 tokenAmount;
              // @dev stake weight
              uint256 weight;
              // @dev locking period - from
              uint64 lockedFrom;
              // @dev locking period - until
              uint64 lockedUntil;
              // @dev indicates if the stake was created as a yield reward
              bool isYield;
            }
            function rewardToken() external view returns (address);
            function poolToken() external view returns (address);
            function isFlashPool() external view returns (bool);
            function weight() external view returns (uint32);
            function lastYieldDistribution() external view returns (uint64);
            function yieldRewardsPerWeight() external view returns (uint256);
            function usersLockingWeight() external view returns (uint256);
            function pendingYieldRewards(address _user) external view returns (uint256);
            function balanceOf(address _user) external view returns (uint256);
            function getDeposit(address _user, uint256 _depositId) external view returns (Deposit memory);
            function getDepositsLength(address _user) external view returns (uint256);
            function stake(uint256 _amount, uint64 _lockedUntil) external;
            function unstake(uint256 _depositId, uint256 _amount) external;
            function sync() external;
            function processRewards() external;
            function setWeight(uint32 _weight) external;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "./zStakePoolBase.sol";
          /**
           * @title Wild Core Pool - Fork of Illuvium Core Pool
           *
           * @notice Core pools represent permanent pools like WILD or WILD/ETH Pair pool,
           *      core pools allow staking for arbitrary periods of time up to 1 year
           *
           * @dev See WildPoolBase for more details
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          contract zStakeCorePool is zStakePoolBase {
            /// @dev Flag indicating pool type, false means "core pool"
            bool public constant override isFlashPool = false;
            /// @dev Pool tokens value available in the pool;
            ///      pool token examples are WILD (WILD core pool) or WILD/ETH pair (LP core pool)
            /// @dev For LP core pool this value doesnt' count for WILD tokens received as Vault rewards
            ///      while for WILD core pool it does count for such tokens as well
            uint256 public poolTokenReserve;
            /**
             * @dev Creates/deploys an instance of the core pool
             *
             * @param _rewardToken WILD ERC20 Token address
             * @param _factory Pool factory zStakePoolFactory instance/address
             * @param _poolToken token the pool operates on, for example WILD or WILD/ETH pair
             * @param _initBlock initial block used to calculate the rewards
             * @param _weight number representing a weight of the pool, actual weight fraction
             *      is calculated as that number divided by the total pools weight and doesn't exceed one
             */
            function initialize(
              address _rewardToken,
              zStakePoolFactory _factory,
              address _poolToken,
              uint64 _initBlock,
              uint32 _weight
            ) initializer public {
              __zStakePoolBase__init(_rewardToken, _factory, _poolToken, _initBlock, _weight);
            }
            // Call this on the implementation contract (not the proxy)
            function initializeImplementation() public initializer {
              __Ownable_init();
              _pause();
            }
            /**
             * @notice Service function to calculate and pay pending vault and yield rewards to the sender
             *
             * @dev Internally executes similar function `_processRewards` from the parent smart contract
             *      to calculate and pay yield rewards; adds vault rewards processing
             *
             * @dev Can be executed by anyone at any time, but has an effect only when
             *      executed by deposit holder and when at least one block passes from the
             *      previous reward processing
             * @dev Executed internally when "staking as a pool" (`stakeAsPool`)
             * @dev When timing conditions are not met (executed too frequently, or after factory
             *      end block), function doesn't throw and exits silently
             */
            function processRewards() external override {
              require(!paused(), "contract is paused");
              _processRewards(msg.sender, true);
            }
            /**
             * @dev Executed internally by the pool itself (from the parent `zStakePoolBase` smart contract)
             *      as part of yield rewards processing logic (`zStakePoolBase._processRewards` function)
             *
             * @param _staker an address which stakes (the yield reward)
             * @param _amount amount to be staked (yield reward amount)
             */
            function stakeAsPool(address _staker, uint256 _amount) external {
              require(!paused(), "contract is paused");
              require(factory.poolExists(msg.sender), "access denied");
              _sync();
              User storage user = users[_staker];
              if (user.tokenAmount > 0) {
                _processRewards(_staker, false);
              }
              uint256 depositWeight = _amount * YEAR_STAKE_WEIGHT_MULTIPLIER;
              Deposit memory newDeposit = Deposit({
                tokenAmount: _amount,
                lockedFrom: uint64(now256()),
                lockedUntil: uint64(now256() + rewardLockPeriod),
                weight: depositWeight,
                isYield: true
              });
              user.tokenAmount += _amount;
              user.totalWeight += depositWeight;
              user.deposits.push(newDeposit);
              usersLockingWeight += depositWeight;
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              // update `poolTokenReserve` only if this is a LP Core Pool (stakeAsPool can be executed only for LP pool)
              poolTokenReserve += _amount;
            }
            /**
             * @inheritdoc zStakePoolBase
             *
             * @dev Additionally to the parent smart contract, updates vault rewards of the holder,
             *      and updates (increases) pool token reserve (pool tokens value available in the pool)
             */
            function _stake(
              address _staker,
              uint256 _amount,
              uint64 _lockedUntil,
              bool _isYield
            ) internal override {
              super._stake(_staker, _amount, _lockedUntil, _isYield);
              poolTokenReserve += _amount;
            }
            /**
             * @inheritdoc zStakePoolBase
             *
             * @dev Additionally to the parent smart contract, updates vault rewards of the holder,
             *      and updates (decreases) pool token reserve (pool tokens value available in the pool)
             */
            function _unstake(
              address _staker,
              uint256 _depositId,
              uint256 _amount
            ) internal override {
              User storage user = users[_staker];
              Deposit memory stakeDeposit = user.deposits[_depositId];
              require(
                stakeDeposit.lockedFrom == 0 || now256() > stakeDeposit.lockedUntil,
                "deposit not yet unlocked"
              );
              poolTokenReserve -= _amount;
              super._unstake(_staker, _depositId, _amount);
            }
            /**
             * @inheritdoc zStakePoolBase
             *
             * @dev Additionally to the parent smart contract, processes vault rewards of the holder,
             *      and for reward pool pool updates (increases) pool token reserve (pool tokens value available in the pool)
             */
            function _processRewards(address _staker, bool _withUpdate)
              internal
              override
              returns (uint256 pendingYield)
            {
              pendingYield = super._processRewards(_staker, _withUpdate);
              // update `poolTokenReserve` only if this is the reward Pool
              if (poolToken == rewardToken) {
                poolTokenReserve += pendingYield;
              }
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract Ownable {
            address private _owner;
            event OwnershipTransferred(
              address indexed previousOwner,
              address indexed newOwner
            );
            /**
             * @dev Initializes the contract setting the deployer as the initial owner.
             */
            constructor() {
              address msgSender = msg.sender;
              _owner = msgSender;
              emit OwnershipTransferred(address(0), msgSender);
            }
            /**
             * @dev Returns the address of the current owner.
             */
            function owner() public view virtual returns (address) {
              return _owner;
            }
            /**
             * @dev Throws if called by any account other than the owner.
             */
            modifier onlyOwner() {
              require(owner() == msg.sender, "Ownable: caller is not the owner");
              _;
            }
            /**
             * @dev Leaves the contract without owner. It will not be possible to call
             * `onlyOwner` functions anymore. Can only be called by the current owner.
             *
             * NOTE: Renouncing ownership will leave the contract without an owner,
             * thereby removing any functionality that is only available to the owner.
             */
            function renounceOwnership() public virtual onlyOwner {
              emit OwnershipTransferred(_owner, address(0));
              _owner = address(0);
            }
            /**
             * @dev Transfers ownership of the contract to a new account (`newOwner`).
             * Can only be called by the current owner.
             */
            function transferOwnership(address newOwner) public virtual onlyOwner {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              emit OwnershipTransferred(_owner, newOwner);
              _owner = newOwner;
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity 0.8.9;
          /**
           * @dev Interface of the ERC20 standard as defined in the EIP.
           */
          interface IERC20 {
            /**
             * @dev Returns the amount of tokens in existence.
             */
            function totalSupply() external view returns (uint256);
            /**
             * @dev Returns the amount of tokens owned by `account`.
             */
            function balanceOf(address account) external view returns (uint256);
            /**
             * @dev Moves `amount` tokens from the caller's account to `recipient`.
             *
             * Returns a boolean value indicating whether the operation succeeded.
             *
             * Emits a {Transfer} event.
             */
            function transfer(address recipient, uint256 amount) external returns (bool);
            /**
             * @dev Returns the remaining number of tokens that `spender` will be
             * allowed to spend on behalf of `owner` through {transferFrom}. This is
             * zero by default.
             *
             * This value changes when {approve} or {transferFrom} are called.
             */
            function allowance(address owner, address spender)
              external
              view
              returns (uint256);
            /**
             * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
             *
             * Returns a boolean value indicating whether the operation succeeded.
             *
             * IMPORTANT: Beware that changing an allowance with this method brings the risk
             * that someone may use both the old and the new allowance by unfortunate
             * transaction ordering. One possible solution to mitigate this race
             * condition is to first reduce the spender's allowance to 0 and set the
             * desired value afterwards:
             * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
             *
             * Emits an {Approval} event.
             */
            function approve(address spender, uint256 amount) external returns (bool);
            /**
             * @dev Moves `amount` tokens from `sender` to `recipient` using the
             * allowance mechanism. `amount` is then deducted from the caller's
             * allowance.
             *
             * Returns a boolean value indicating whether the operation succeeded.
             *
             * Emits a {Transfer} event.
             */
            function transferFrom(
              address sender,
              address recipient,
              uint256 amount
            ) external returns (bool);
            /**
             * @dev Emitted when `value` tokens are moved from one account (`from`) to
             * another (`to`).
             *
             * Note that `value` may be zero.
             */
            event Transfer(address indexed from, address indexed to, uint256 value);
            /**
             * @dev Emitted when the allowance of a `spender` for an `owner` is set by
             * a call to {approve}. `value` is the new allowance.
             */
            event Approval(address indexed owner, address indexed spender, uint256 value);
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/ContextUpgradeable.sol";
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module which provides a basic access control mechanism, where
           * there is an account (an owner) that can be granted exclusive access to
           * specific functions.
           *
           * By default, the owner account will be the one that deploys the contract. This
           * can later be changed with {transferOwnership}.
           *
           * This module is used through inheritance. It will make available the modifier
           * `onlyOwner`, which can be applied to your functions to restrict their use to
           * the owner.
           */
          abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
              address private _owner;
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
              /**
               * @dev Initializes the contract setting the deployer as the initial owner.
               */
              function __Ownable_init() internal initializer {
                  __Context_init_unchained();
                  __Ownable_init_unchained();
              }
              function __Ownable_init_unchained() internal initializer {
                  _setOwner(_msgSender());
              }
              /**
               * @dev Returns the address of the current owner.
               */
              function owner() public view virtual returns (address) {
                  return _owner;
              }
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(owner() == _msgSender(), "Ownable: caller is not the owner");
                  _;
              }
              /**
               * @dev Leaves the contract without owner. It will not be possible to call
               * `onlyOwner` functions anymore. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby removing any functionality that is only available to the owner.
               */
              function renounceOwnership() public virtual onlyOwner {
                  _setOwner(address(0));
              }
              /**
               * @dev Transfers ownership of the contract to a new account (`newOwner`).
               * Can only be called by the current owner.
               */
              function transferOwnership(address newOwner) public virtual onlyOwner {
                  require(newOwner != address(0), "Ownable: new owner is the zero address");
                  _setOwner(newOwner);
              }
              function _setOwner(address newOwner) private {
                  address oldOwner = _owner;
                  _owner = newOwner;
                  emit OwnershipTransferred(oldOwner, newOwner);
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../utils/ContextUpgradeable.sol";
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Contract module which allows children to implement an emergency stop
           * mechanism that can be triggered by an authorized account.
           *
           * This module is used through inheritance. It will make available the
           * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
           * the functions of your contract. Note that they will not be pausable by
           * simply including this module, only once the modifiers are put in place.
           */
          abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
              /**
               * @dev Emitted when the pause is triggered by `account`.
               */
              event Paused(address account);
              /**
               * @dev Emitted when the pause is lifted by `account`.
               */
              event Unpaused(address account);
              bool private _paused;
              /**
               * @dev Initializes the contract in unpaused state.
               */
              function __Pausable_init() internal initializer {
                  __Context_init_unchained();
                  __Pausable_init_unchained();
              }
              function __Pausable_init_unchained() internal initializer {
                  _paused = false;
              }
              /**
               * @dev Returns true if the contract is paused, and false otherwise.
               */
              function paused() public view virtual returns (bool) {
                  return _paused;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is not paused.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              modifier whenNotPaused() {
                  require(!paused(), "Pausable: paused");
                  _;
              }
              /**
               * @dev Modifier to make a function callable only when the contract is paused.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              modifier whenPaused() {
                  require(paused(), "Pausable: not paused");
                  _;
              }
              /**
               * @dev Triggers stopped state.
               *
               * Requirements:
               *
               * - The contract must not be paused.
               */
              function _pause() internal virtual whenNotPaused {
                  _paused = true;
                  emit Paused(_msgSender());
              }
              /**
               * @dev Returns to normal state.
               *
               * Requirements:
               *
               * - The contract must be paused.
               */
              function _unpause() internal virtual whenPaused {
                  _paused = false;
                  emit Unpaused(_msgSender());
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "./interfaces/IPool.sol";
          import "./interfaces/ICorePool.sol";
          import "./ReentrancyGuardUpgradeable.sol";
          import "./zStakePoolFactory.sol";
          import "./utils/SafeERC20.sol";
          import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
          /**
           * @title Pool Base - Fork of Illuvium Pool Base
           *
           * @notice An abstract contract containing common logic for a staking pool
           *
           * @dev Deployment and initialization.
           *      Any pool deployed must be bound to the deployed pool factory (zStakePoolFactory)
           *      Additionally, 3 token instance addresses must be defined on deployment:
           *          - Reward token address
           *          - pool token address, it can be the reward token address, LP pair address, and others
           *
           * @dev Pool weight defines the fraction of the yield current pool receives among the other pools,
           *      pool factory is responsible for the weight synchronization between the pools.
           * @dev The weight is logically 10% for reward token pool and 90% for LP pool.
           *      Since Solidity doesn't support fractions the weight is defined by the division of
           *      pool weight by total pools weight (sum of all registered pools within the factory)
           *
           * @author Pedro Bergamini, reviewed by Basil Gorin, modified by Zer0
           */
          abstract contract zStakePoolBase is
            IPool,
            ReentrancyGuardUpgradeable,
            OwnableUpgradeable,
            PausableUpgradeable
          {
            /// @dev Data structure representing token holder using a pool
            struct User {
              // @dev Total staked amount
              uint256 tokenAmount;
              // @dev Total weight
              uint256 totalWeight;
              // @dev Auxiliary variable for yield calculation
              uint256 subYieldRewards;
              // @dev An array of holder's deposits
              Deposit[] deposits;
            }
            function isFlashPool() external view virtual override returns (bool) {
              return false;
            }
            /// @dev The reward token
            address public override rewardToken;
            /// @dev Token holder storage, maps token holder address to their data record
            mapping(address => User) public users;
            /// @dev Link to the pool factory zStakePoolFactory instance
            zStakePoolFactory public factory;
            /// @dev Link to the pool token instance, for example WILD or WILD/ETH pair
            address public override poolToken;
            /// @dev Pool weight
            uint32 public override weight;
            /// @dev Block number of the last yield distribution event
            uint64 public override lastYieldDistribution;
            /// @dev Used to calculate yield rewards
            /// @dev This value is different from "reward per token" used in locked pool
            /// @dev Note: stakes are different in duration and "weight" reflects that
            uint256 public override yieldRewardsPerWeight;
            /// @dev Used to calculate yield rewards, keeps track of the tokens weight locked in staking
            uint256 public override usersLockingWeight;
            /// @dev The duration of time to lock rewards
            uint256 public rewardLockPeriod;
            /**
             * @dev Stake weight is proportional to deposit amount and time locked, precisely
             *      "deposit amount wei multiplied by (fraction of the year locked plus one)"
             * @dev To avoid significant precision loss due to multiplication by "fraction of the year" [0, 1],
             *      weight is stored multiplied by 1e6 constant, as an integer
             * @dev Corner case 1: if time locked is zero, weight is deposit amount multiplied by 1e6
             * @dev Corner case 2: if time locked is one year, fraction of the year locked is one, and
             *      weight is a deposit amount multiplied by 2 * 1e6
             */
            uint256 internal constant WEIGHT_MULTIPLIER = 1e6;
            /**
             * @dev When we know beforehand that staking is done for a year, and fraction of the year locked is one,
             *      we use simplified calculation and use the following constant instead previos one
             */
            uint256 internal constant YEAR_STAKE_WEIGHT_MULTIPLIER = 2 * WEIGHT_MULTIPLIER;
            /**
             * @dev Rewards per weight are stored multiplied by 1e12, as integers.
             */
            uint256 internal constant REWARD_PER_WEIGHT_MULTIPLIER = 1e12;
            /**
             * @dev Fired in _stake() and stake()
             *
             * @param _by an address which performed an operation, usually token holder
             * @param _from token holder address, the tokens will be returned to that address
             * @param amount amount of tokens staked
             */
            event Staked(address indexed _by, address indexed _from, uint256 amount);
            /**
             * @dev Fired in _updateStakeLock() and updateStakeLock()
             *
             * @param _by an address which performed an operation
             * @param depositId updated deposit ID
             * @param lockedFrom deposit locked from value
             * @param lockedUntil updated deposit locked until value
             */
            event StakeLockUpdated(
              address indexed _by,
              uint256 depositId,
              uint64 lockedFrom,
              uint64 lockedUntil
            );
            /**
             * @dev Fired in _unstake() and unstake()
             *
             * @param _by an address which performed an operation, usually token holder
             * @param _to an address which received the unstaked tokens, usually token holder
             * @param amount amount of tokens unstaked
             */
            event Unstaked(address indexed _by, address indexed _to, uint256 amount);
            /**
             * @dev Fired in _sync(), sync() and dependent functions (stake, unstake, etc.)
             *
             * @param _by an address which performed an operation
             * @param yieldRewardsPerWeight updated yield rewards per weight value
             * @param lastYieldDistribution usually, current block number
             */
            event Synchronized(
              address indexed _by,
              uint256 yieldRewardsPerWeight,
              uint64 lastYieldDistribution
            );
            /**
             * @dev Fired in _processRewards(), processRewards() and dependent functions (stake, unstake, etc.)
             *
             * @param _by an address which performed an operation
             * @param _to an address which claimed the yield reward
             * @param amount amount of yield paid
             */
            event YieldClaimed(address indexed _by, address indexed _to, uint256 amount);
            /**
             * @dev Fired in setWeight()
             *
             * @param _by an address which performed an operation, always a factory
             * @param _fromVal old pool weight value
             * @param _toVal new pool weight value
             */
            event PoolWeightUpdated(address indexed _by, uint32 _fromVal, uint32 _toVal);
            /**
             * @dev Overridden in sub-contracts to construct the pool
             *
             * @param _rewardToken Reward ERC20 Token address
             * @param _factory Pool factory zStakePoolFactory instance/address
             * @param _poolToken token the pool operates on, for example WILD or WILD/ETH pair
             * @param _initBlock initial block used to calculate the rewards
             *      note: _initBlock can be set to the future effectively meaning _sync() calls will do nothing
             * @param _weight number representing a weight of the pool, actual weight fraction
             *      is calculated as that number divided by the total pools weight and doesn't exceed one
             */
            function __zStakePoolBase__init(
              address _rewardToken,
              zStakePoolFactory _factory,
              address _poolToken,
              uint64 _initBlock,
              uint32 _weight
            ) public initializer {
              __Ownable_init();
              // verify the inputs are set
              require(address(_factory) != address(0), "factory address not set");
              require(_poolToken != address(0), "pool token address not set");
              require(_initBlock > 0, "init block not set");
              require(_weight > 0, "pool weight not set");
              // save the inputs into internal state variables
              factory = _factory;
              poolToken = _poolToken;
              weight = _weight;
              rewardToken = _rewardToken;
              // init the dependent internal state variables
              lastYieldDistribution = _initBlock;
              rewardLockPeriod = 365 days;
            }
            /**
             * @notice Calculates current yield rewards value available for address specified
             *
             * @param _staker an address to calculate yield rewards value for
             * @return calculated yield reward value for the given address
             */
            function pendingYieldRewards(address _staker) external view override returns (uint256) {
              // `newYieldRewardsPerWeight` will store stored or recalculated value for `yieldRewardsPerWeight`
              uint256 newYieldRewardsPerWeight;
              // if smart contract state was not updated recently, `yieldRewardsPerWeight` value
              // is outdated and we need to recalculate it in order to calculate pending rewards correctly
              if (blockNumber() > lastYieldDistribution && usersLockingWeight != 0) {
                uint256 multiplier = blockNumber() - lastYieldDistribution;
                uint256 rewards = (multiplier * weight * factory.getRewardTokensPerBlock()) /
                  factory.totalWeight();
                // recalculated value for `yieldRewardsPerWeight`
                newYieldRewardsPerWeight =
                  rewardToWeight(rewards, usersLockingWeight) +
                  yieldRewardsPerWeight;
              } else {
                // if smart contract state is up to date, we don't recalculate
                newYieldRewardsPerWeight = yieldRewardsPerWeight;
              }
              // based on the rewards per weight value, calculate pending rewards;
              User memory user = users[_staker];
              uint256 pending = weightToReward(user.totalWeight, newYieldRewardsPerWeight) -
                user.subYieldRewards;
              return pending;
            }
            /**
             * @notice Returns total staked token balance for the given address
             *
             * @param _user an address to query balance for
             * @return total staked token balance
             */
            function balanceOf(address _user) external view override returns (uint256) {
              // read specified user token amount and return
              return users[_user].tokenAmount;
            }
            /**
             * @notice Returns information on the given deposit for the given address
             *
             * @dev See getDepositsLength
             *
             * @param _user an address to query deposit for
             * @param _depositId zero-indexed deposit ID for the address specified
             * @return deposit info as Deposit structure
             */
            function getDeposit(address _user, uint256 _depositId)
              external
              view
              override
              returns (Deposit memory)
            {
              // read deposit at specified index and return
              return users[_user].deposits[_depositId];
            }
            /**
             * @notice Returns number of deposits for the given address. Allows iteration over deposits.
             *
             * @dev See getDeposit
             *
             * @param _user an address to query deposit length for
             * @return number of deposits for the given address
             */
            function getDepositsLength(address _user) external view override returns (uint256) {
              // read deposits array length and return
              return users[_user].deposits.length;
            }
            /**
             * @notice Stakes specified amount of tokens for the specified amount of time,
             *      and pays pending yield rewards if any
             *
             * @dev Requires amount to stake to be greater than zero
             *
             * @param _amount amount of tokens to stake
             * @param _lockUntil stake period as unix timestamp; zero means no locking
             */
            function stake(uint256 _amount, uint64 _lockUntil) external override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _stake(msg.sender, _amount, _lockUntil, false);
            }
            /**
             * @notice Unstakes specified amount of tokens, and pays pending yield rewards if any
             *
             * @dev Requires amount to unstake to be greater than zero
             *
             * @param _depositId deposit ID to unstake from, zero-indexed
             * @param _amount amount of tokens to unstake
             */
            function unstake(uint256 _depositId, uint256 _amount) external override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _unstake(msg.sender, _depositId, _amount);
            }
            /**
             * @notice Extends locking period for a given deposit
             *
             * @dev Requires new lockedUntil value to be:
             *      higher than the current one, and
             *      in the future, but
             *      no more than 1 year in the future
             *
             * @param depositId updated deposit ID
             * @param lockedUntil updated deposit locked until value
             */
            function updateStakeLock(uint256 depositId, uint64 lockedUntil) external {
              require(!paused(), "contract is paused");
              // Sync and give user rewards
              _sync();
              _processRewards(msg.sender, false);
              // delegate call to an internal function
              _updateStakeLock(msg.sender, depositId, lockedUntil);
              // Update subyieldrewards so that the user is not owed anything
              User storage user = users[msg.sender];
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
            }
            /**
             * @notice Service function to synchronize pool state with current time
             *
             * @dev Can be executed by anyone at any time, but has an effect only when
             *      at least one block passes between synchronizations
             * @dev Executed internally when staking, unstaking, processing rewards in order
             *      for calculations to be correct and to reflect state progress of the contract
             * @dev When timing conditions are not met (executed too frequently, or after factory
             *      end block), function doesn't throw and exits silently
             */
            function sync() external override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _sync();
            }
            /**
             * @notice Service function to calculate and pay pending yield rewards to the sender
             *
             * @dev Can be executed by anyone at any time, but has an effect only when
             *      executed by deposit holder and when at least one block passes from the
             *      previous reward processing
             * @dev Executed internally when staking and unstaking, executes sync() under the hood
             *      before making further calculations and payouts
             * @dev When timing conditions are not met (executed too frequently, or after factory
             *      end block), function doesn't throw and exits silently
             *
             */
            function processRewards() external virtual override {
              require(!paused(), "contract is paused");
              // delegate call to an internal function
              _processRewards(msg.sender, true);
            }
            /**
             * @dev Executed by the factory to modify pool weight; the factory is expected
             *      to keep track of the total pools weight when updating
             *
             * @dev Set weight to zero to disable the pool
             *
             * @param _weight new weight to set for the pool
             */
            function setWeight(uint32 _weight) external override {
              require(!paused(), "contract is paused");
              // verify function is executed by the factory
              require(msg.sender == address(factory), "access denied");
              // emit an event logging old and new weight values
              emit PoolWeightUpdated(msg.sender, weight, _weight);
              // set the new weight value
              weight = _weight;
            }
            /**
             * @dev Similar to public pendingYieldRewards, but performs calculations based on
             *      current smart contract state only, not taking into account any additional
             *      time/blocks which might have passed
             *
             * @param _staker an address to calculate yield rewards value for
             * @return pending calculated yield reward value for the given address
             */
            function _pendingYieldRewards(address _staker) internal view returns (uint256 pending) {
              // read user data structure into memory
              User memory user = users[_staker];
              // and perform the calculation using the values read
              return weightToReward(user.totalWeight, yieldRewardsPerWeight) - user.subYieldRewards;
            }
            /**
             * @dev Used internally, mostly by children implementations, see stake()
             *
             * @param _staker an address which stakes tokens and which will receive them back
             * @param _amount amount of tokens to stake
             * @param _lockUntil stake period as unix timestamp; zero means no locking
             * @param _isYield a flag indicating if that stake is created to store yield reward
             *      from the previously unstaked stake
             */
            function _stake(
              address _staker,
              uint256 _amount,
              uint64 _lockUntil,
              bool _isYield
            ) internal virtual {
              // validate the inputs
              require(_amount > 0, "zero amount");
              require(
                _lockUntil == 0 || (_lockUntil > now256() && _lockUntil - now256() <= 365 days),
                "invalid lock interval"
              );
              // update smart contract state
              _sync();
              // get a link to user data struct, we will write to it later
              User storage user = users[_staker];
              // process current pending rewards if any
              if (user.tokenAmount > 0) {
                _processRewards(_staker, false);
              }
              // in most of the cases added amount `addedAmount` is simply `_amount`
              // however for deflationary tokens this can be different
              // read the current balance
              uint256 previousBalance = IERC20(poolToken).balanceOf(address(this));
              // transfer `_amount`; note: some tokens may get burnt here
              transferPoolTokenFrom(address(msg.sender), address(this), _amount);
              // read new balance, usually this is just the difference `previousBalance - _amount`
              uint256 newBalance = IERC20(poolToken).balanceOf(address(this));
              // calculate real amount taking into account deflation
              uint256 addedAmount = newBalance - previousBalance;
              // set the `lockFrom` and `lockUntil` taking into account that
              // zero value for `_lockUntil` means "no locking" and leads to zero values
              // for both `lockFrom` and `lockUntil`
              uint64 lockFrom = _lockUntil > 0 ? uint64(now256()) : 0;
              uint64 lockUntil = _lockUntil;
              // stake weight formula rewards for locking
              uint256 stakeWeight = (((lockUntil - lockFrom) * WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * addedAmount;
              // makes sure stakeWeight is valid
              assert(stakeWeight > 0);
              // create and save the deposit (append it to deposits array)
              Deposit memory deposit = Deposit({
                tokenAmount: addedAmount,
                weight: stakeWeight,
                lockedFrom: lockFrom,
                lockedUntil: lockUntil,
                isYield: _isYield
              });
              // deposit ID is an index of the deposit in `deposits` array
              user.deposits.push(deposit);
              // update user record
              user.tokenAmount += addedAmount;
              user.totalWeight += stakeWeight;
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              // update global variable
              usersLockingWeight += stakeWeight;
              // emit an event
              emit Staked(msg.sender, _staker, _amount);
            }
            /**
             * @dev Allows for the rewardLockPeriod to be modified.
             */
            function changeRewardLockPeriod(uint256 _rewardLockPeriod) external onlyOwner {
              require(rewardLockPeriod != _rewardLockPeriod, "same rewardLockPeriod");
              require(_rewardLockPeriod <= 365 days, "too long lock period");
              rewardLockPeriod = _rewardLockPeriod;
            }
            /**
             * @dev Used internally, mostly by children implementations, see unstake()
             *
             * @param _staker an address which unstakes tokens (which previously staked them)
             * @param _depositId deposit ID to unstake from, zero-indexed
             * @param _amount amount of tokens to unstake
             */
            function _unstake(
              address _staker,
              uint256 _depositId,
              uint256 _amount
            ) internal virtual {
              // verify an amount is set
              require(_amount > 0, "zero amount");
              // get a link to user data struct, we will write to it later
              User storage user = users[_staker];
              // get a link to the corresponding deposit, we may write to it later
              Deposit storage stakeDeposit = user.deposits[_depositId];
              // deposit structure may get deleted, so we save isYield flag to be able to use it
              bool isYield = stakeDeposit.isYield;
              // verify available balance
              // if staker address ot deposit doesn't exist this check will fail as well
              require(stakeDeposit.tokenAmount >= _amount, "amount exceeds stake");
              // update smart contract state
              _sync();
              // and process current pending rewards if any
              _processRewards(_staker, false);
              // recalculate deposit weight
              uint256 previousWeight = stakeDeposit.weight;
              uint256 newWeight = (((stakeDeposit.lockedUntil - stakeDeposit.lockedFrom) *
                WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * (stakeDeposit.tokenAmount - _amount);
              // update the deposit, or delete it if its depleted
              if (stakeDeposit.tokenAmount - _amount == 0) {
                delete user.deposits[_depositId];
              } else {
                stakeDeposit.tokenAmount -= _amount;
                stakeDeposit.weight = newWeight;
              }
              // update user record
              user.tokenAmount -= _amount;
              user.totalWeight = user.totalWeight - previousWeight + newWeight;
              user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              // update global variable
              usersLockingWeight = usersLockingWeight - previousWeight + newWeight;
              // if the deposit was created by the pool itself as a yield reward
              if (isYield) {
                // @TODO: Replace this
                // Make it so it transfers tokens from escrow rewards pool to staker
                // mint the yield via the factory
                factory.transferRewardYield(msg.sender, _amount);
              } else {
                // otherwise just return tokens back to holder
                transferPoolToken(msg.sender, _amount);
              }
              // emit an event
              emit Unstaked(msg.sender, _staker, _amount);
            }
            /**
             * @dev Used internally, mostly by children implementations, see sync()
             *
             * @dev Updates smart contract state (`yieldRewardsPerWeight`, `lastYieldDistribution`),
             */
            function _sync() internal virtual {
              if (blockNumber() <= lastYieldDistribution) {
                return;
              }
              // if locking weight is zero - update only `lastYieldDistribution` and exit
              if (usersLockingWeight == 0) {
                lastYieldDistribution = uint64(blockNumber());
                return;
              }
              // to calculate the reward we need to know how many blocks passed, and reward per block
              uint256 currentBlock = blockNumber();
              uint256 blocksPassed = currentBlock - lastYieldDistribution;
              uint256 rewardPerBlock = factory.getRewardTokensPerBlock();
              // calculate the reward
              uint256 rewardAmount = (blocksPassed * rewardPerBlock * weight) / factory.totalWeight();
              // update rewards per weight and `lastYieldDistribution`
              yieldRewardsPerWeight += rewardToWeight(rewardAmount, usersLockingWeight);
              lastYieldDistribution = uint64(currentBlock);
              // emit an event
              emit Synchronized(msg.sender, yieldRewardsPerWeight, lastYieldDistribution);
            }
            /**
             * @dev Used internally, mostly by children implementations, see processRewards()
             *
             * @param _staker an address which receives the reward (which has staked some tokens earlier)
             * @param _withUpdate flag allowing to disable synchronization (see sync()) if set to false
             * @return pendingYield the rewards calculated and optionally re-staked
             */
            function _processRewards(address _staker, bool _withUpdate)
              internal
              virtual
              returns (uint256 pendingYield)
            {
              // update smart contract state if required
              if (_withUpdate) {
                _sync();
              }
              // calculate pending yield rewards, this value will be returned
              pendingYield = _pendingYieldRewards(_staker);
              // if pending yield is zero - just return silently
              if (pendingYield == 0) return 0;
              // get link to a user data structure, we will write into it later
              User storage user = users[_staker];
              if (poolToken == rewardToken) {
                // calculate pending yield weight,
                // 2e6 is the bonus weight when staking for 1 year
                uint256 depositWeight = pendingYield * YEAR_STAKE_WEIGHT_MULTIPLIER;
                // if the pool is the Reward Token Pool - create new Reward Token deposit
                // and save it - push it into deposits array
                Deposit memory newDeposit = Deposit({
                  tokenAmount: pendingYield,
                  lockedFrom: uint64(now256()),
                  lockedUntil: uint64(now256() + rewardLockPeriod), // staking yield for 1 year
                  weight: depositWeight,
                  isYield: true
                });
                user.deposits.push(newDeposit);
                // update user record
                user.tokenAmount += pendingYield;
                user.totalWeight += depositWeight;
                // update global variable
                usersLockingWeight += depositWeight;
              } else {
                // for other pools - stake as pool
                // This will stake the rewards into the reward token pool
                address rewardPool = factory.getPoolAddress(rewardToken);
                ICorePool(rewardPool).stakeAsPool(_staker, pendingYield);
              }
              // update users's record for `subYieldRewards` if requested
              if (_withUpdate) {
                user.subYieldRewards = weightToReward(user.totalWeight, yieldRewardsPerWeight);
              }
              // emit an event
              emit YieldClaimed(msg.sender, _staker, pendingYield);
            }
            /**
             * @dev See updateStakeLock()
             *
             * @param _staker an address to update stake lock
             * @param _depositId updated deposit ID
             * @param _lockedUntil updated deposit locked until value
             */
            function _updateStakeLock(
              address _staker,
              uint256 _depositId,
              uint64 _lockedUntil
            ) internal {
              // validate the input time
              require(_lockedUntil > now256(), "lock should be in the future");
              // get a link to user data struct, we will write to it later
              User storage user = users[_staker];
              // get a link to the corresponding deposit, we may write to it later
              Deposit storage stakeDeposit = user.deposits[_depositId];
              // validate the input against deposit structure
              require(_lockedUntil > stakeDeposit.lockedUntil, "invalid new lock");
              // verify locked from and locked until values
              if (stakeDeposit.lockedFrom == 0) {
                // Was never locked
                require(_lockedUntil - now256() <= 365 days, "max lock period is 365 days");
                stakeDeposit.lockedFrom = uint64(now256());
              } else {
                // Was locked (but for less than 365 days)
                require(_lockedUntil - stakeDeposit.lockedFrom <= 365 days, "max lock period is 365 days");
              }
              // update locked until value, calculate new weight
              stakeDeposit.lockedUntil = _lockedUntil;
              uint256 newWeight = (((stakeDeposit.lockedUntil - stakeDeposit.lockedFrom) *
                WEIGHT_MULTIPLIER) /
                365 days +
                WEIGHT_MULTIPLIER) * stakeDeposit.tokenAmount;
              // save previous weight
              uint256 previousWeight = stakeDeposit.weight;
              // update weight
              stakeDeposit.weight = newWeight;
              // update user total weight and global locking weight
              user.totalWeight = user.totalWeight - previousWeight + newWeight;
              usersLockingWeight = usersLockingWeight - previousWeight + newWeight;
              // emit an event
              emit StakeLockUpdated(_staker, _depositId, stakeDeposit.lockedFrom, _lockedUntil);
            }
            /**
             * @dev Converts stake weight (not to be mixed with the pool weight) to
             *      token reward value, applying the 10^12 division on weight
             *
             * @param _weight stake weight
             * @param rewardPerWeight reward per weight
             * @return reward value normalized to 10^12
             */
            function weightToReward(uint256 _weight, uint256 rewardPerWeight) public pure returns (uint256) {
              // apply the formula and return
              return (_weight * rewardPerWeight) / REWARD_PER_WEIGHT_MULTIPLIER;
            }
            /**
             * @dev Converts reward value to stake weight (not to be mixed with the pool weight),
             *      applying the 10^12 multiplication on the reward
             *      - OR -
             * @dev Converts reward value to reward/weight if stake weight is supplied as second
             *      function parameter instead of reward/weight
             *
             * @param reward yield reward
             * @param rewardPerWeight reward/weight (or stake weight)
             * @return stake weight (or reward/weight)
             */
            function rewardToWeight(uint256 reward, uint256 rewardPerWeight) public pure returns (uint256) {
              // apply the reverse formula and return
              return (reward * REWARD_PER_WEIGHT_MULTIPLIER) / rewardPerWeight;
            }
            /**
             * @dev Testing time-dependent functionality is difficult and the best way of
             *      doing it is to override block number in helper test smart contracts
             *
             * @return `block.number` in mainnet, custom values in testnets (if overridden)
             */
            function blockNumber() public view virtual returns (uint256) {
              // return current block number
              return block.number;
            }
            /**
             * @dev Testing time-dependent functionality is difficult and the best way of
             *      doing it is to override time in helper test smart contracts
             *
             * @return `block.timestamp` in mainnet, custom values in testnets (if overridden)
             */
            function now256() public view virtual returns (uint256) {
              // return current block timestamp
              return block.timestamp;
            }
            /**
             * @dev Sets the pause status of the contract.
             */
            function setPauseStatus(bool toPause) public onlyOwner {
              if (toPause) {
                require(!paused(), "Pausable: paused");
                _pause();
              } else {
                require(paused(), "Pausable: not paused");
                _unpause();
              }
            }
            /**
             * @dev Executes SafeERC20.safeTransfer on a pool token
             *
             * @dev Reentrancy safety enforced via `ReentrancyGuard.nonReentrant`
             */
            function transferPoolToken(address _to, uint256 _value) internal nonReentrant {
              // just delegate call to the target
              SafeERC20.safeTransfer(IERC20(poolToken), _to, _value);
            }
            /**
             * @dev Executes SafeERC20.safeTransferFrom on a pool token
             *
             * @dev Reentrancy safety enforced via `ReentrancyGuard.nonReentrant`
             */
            function transferPoolTokenFrom(
              address _from,
              address _to,
              uint256 _value
            ) internal nonReentrant {
              // just delegate call to the target
              SafeERC20.safeTransferFrom(IERC20(poolToken), _from, _to, _value);
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity 0.8.9;
          import "./IPool.sol";
          interface ICorePool is IPool {
            function poolTokenReserve() external view returns (uint256);
            function stakeAsPool(address _staker, uint256 _amount) external;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
          /**
           * @dev Contract module that helps prevent reentrant calls to a function.
           *
           * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
           * available, which can be applied to functions to make sure there are no nested
           * (reentrant) calls to them.
           *
           * Note that because there is a single `nonReentrant` guard, functions marked as
           * `nonReentrant` may not call one another. This can be worked around by making
           * those functions `private`, and then adding `external` `nonReentrant` entry
           * points to them.
           *
           * TIP: If you would like to learn more about reentrancy and alternative ways
           * to protect against it, check out our blog post
           * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
           */
          abstract contract ReentrancyGuardUpgradeable is Initializable {
              // Booleans are more expensive than uint256 or any type that takes up a full
              // word because each write operation emits an extra SLOAD to first read the
              // slot's contents, replace the bits taken up by the boolean, and then write
              // back. This is the compiler's defense against contract upgrades and
              // pointer aliasing, and it cannot be disabled.
              // The values being non-zero value makes deployment a bit more expensive,
              // but in exchange the refund on every call to nonReentrant will be lower in
              // amount. Since refunds are capped to a percentage of the total
              // transaction's gas, it is best to keep them low in cases like this one, to
              // increase the likelihood of the full refund coming into effect.
              uint256 private constant _NOT_ENTERED = 1;
              uint256 private constant _ENTERED = 2;
              uint256 private _status;
              function __ReentrancyGuard_init() internal initializer {
                  __ReentrancyGuard_init_unchained();
              }
              function __ReentrancyGuard_init_unchained() internal initializer {
                  _status = _NOT_ENTERED;
              }
              /**
               * @dev Prevents a contract from calling itself, directly or indirectly.
               * Calling a `nonReentrant` function from another `nonReentrant`
               * function is not supported. It is possible to prevent this from happening
               * by making the `nonReentrant` function external, and make it call a
               * `private` function that does the actual work.
               */
              modifier nonReentrant() {
                  // On the first call to nonReentrant, _notEntered will be true
                  require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                  // Any calls to nonReentrant after this point will fail
                  _status = _ENTERED;
                  _;
                  // By storing the original value once again, a refund is triggered (see
                  // https://eips.ethereum.org/EIPS/eip-2200)
                  _status = _NOT_ENTERED;
              }
              uint256[49] private __gap;
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.9;
          import "../interfaces/IERC20.sol";
          import "./AddressUpgradeable.sol";
          /**
           * @title SafeERC20
           * @dev Wrappers around ERC20 operations that throw on failure (when the token
           * contract returns false). Tokens that return no value (and instead revert or
           * throw on failure) are also supported, non-reverting calls are assumed to be
           * successful.
           * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
           * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
           */
          library SafeERC20 {
            using AddressUpgradeable for address;
            function safeTransfer(
              IERC20 token,
              address to,
              uint256 value
            ) internal {
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.transfer.selector, to, value)
              );
            }
            function safeTransferFrom(
              IERC20 token,
              address from,
              address to,
              uint256 value
            ) internal {
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
              );
            }
            /**
             * @dev Deprecated. This function has issues similar to the ones found in
             * {IERC20-approve}, and its usage is discouraged.
             *
             * Whenever possible, use {safeIncreaseAllowance} and
             * {safeDecreaseAllowance} instead.
             */
            function safeApprove(
              IERC20 token,
              address spender,
              uint256 value
            ) internal {
              // safeApprove should only be called when setting an initial allowance,
              // or when resetting it to zero. To increase and decrease it, use
              // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
              // solhint-disable-next-line max-line-length
              require(
                (value == 0) || (token.allowance(address(this), spender) == 0),
                "SafeERC20: approve from non-zero to non-zero allowance"
              );
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.approve.selector, spender, value)
              );
            }
            function safeIncreaseAllowance(
              IERC20 token,
              address spender,
              uint256 value
            ) internal {
              uint256 newAllowance = token.allowance(address(this), spender) + value;
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
              );
            }
            function safeDecreaseAllowance(
              IERC20 token,
              address spender,
              uint256 value
            ) internal {
              uint256 newAllowance = token.allowance(address(this), spender) - value;
              _callOptionalReturn(
                token,
                abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
              );
            }
            /**
             * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
             * on the return value: the return value is optional (but if data is returned, it must not be false).
             * @param token The token targeted by the call.
             * @param data The call data (encoded using abi.encode or one of its variants).
             */
            function _callOptionalReturn(IERC20 token, bytes memory data) private {
              // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
              // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
              // the target address contains contract code and also asserts for success in the low-level call.
              bytes memory returndata = address(token).functionCall(
                data,
                "SafeERC20: low-level call failed"
              );
              if (returndata.length > 0) {
                // Return data is optional
                // solhint-disable-next-line max-line-length
                require(
                  abi.decode(returndata, (bool)),
                  "SafeERC20: ERC20 operation did not succeed"
                );
              }
            }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          /**
           * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
           * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
           * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
           * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
           *
           * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
           * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
           *
           * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
           * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
           */
          abstract contract Initializable {
              /**
               * @dev Indicates that the contract has been initialized.
               */
              bool private _initialized;
              /**
               * @dev Indicates that the contract is in the process of being initialized.
               */
              bool private _initializing;
              /**
               * @dev Modifier to protect an initializer function from being invoked twice.
               */
              modifier initializer() {
                  require(_initializing || !_initialized, "Initializable: contract is already initialized");
                  bool isTopLevelCall = !_initializing;
                  if (isTopLevelCall) {
                      _initializing = true;
                      _initialized = true;
                  }
                  _;
                  if (isTopLevelCall) {
                      _initializing = false;
                  }
              }
          }
          // SPDX-License-Identifier: MIT
          pragma solidity ^0.8.0;
          import "../proxy/utils/Initializable.sol";
          /**
           * @dev Provides information about the current execution context, including the
           * sender of the transaction and its data. While these are generally available
           * via msg.sender and msg.data, they should not be accessed in such a direct
           * manner, since when dealing with meta-transactions the account sending and
           * paying for execution may not be the actual sender (as far as an application
           * is concerned).
           *
           * This contract is only required for intermediate, library-like contracts.
           */
          abstract contract ContextUpgradeable is Initializable {
              function __Context_init() internal initializer {
                  __Context_init_unchained();
              }
              function __Context_init_unchained() internal initializer {
              }
              function _msgSender() internal view virtual returns (address) {
                  return msg.sender;
              }
              function _msgData() internal view virtual returns (bytes calldata) {
                  return msg.data;
              }
              uint256[50] private __gap;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.0 (utils/Address.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Collection of functions related to the address type
           */
          library AddressUpgradeable {
              /**
               * @dev Returns true if `account` is a contract.
               *
               * [IMPORTANT]
               * ====
               * It is unsafe to assume that an address for which this function returns
               * false is an externally-owned account (EOA) and not a contract.
               *
               * Among others, `isContract` will return false for the following
               * types of addresses:
               *
               *  - an externally-owned account
               *  - a contract in construction
               *  - an address where a contract will be created
               *  - an address where a contract lived, but was destroyed
               * ====
               */
              function isContract(address account) internal view returns (bool) {
                  // This method relies on extcodesize, which returns 0 for contracts in
                  // construction, since the code is only stored at the end of the
                  // constructor execution.
                  uint256 size;
                  assembly {
                      size := extcodesize(account)
                  }
                  return size > 0;
              }
              /**
               * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
               * `recipient`, forwarding all available gas and reverting on errors.
               *
               * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
               * of certain opcodes, possibly making contracts go over the 2300 gas limit
               * imposed by `transfer`, making them unable to receive funds via
               * `transfer`. {sendValue} removes this limitation.
               *
               * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
               *
               * IMPORTANT: because control is transferred to `recipient`, care must be
               * taken to not create reentrancy vulnerabilities. Consider using
               * {ReentrancyGuard} or the
               * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
               */
              function sendValue(address payable recipient, uint256 amount) internal {
                  require(address(this).balance >= amount, "Address: insufficient balance");
                  (bool success, ) = recipient.call{value: amount}("");
                  require(success, "Address: unable to send value, recipient may have reverted");
              }
              /**
               * @dev Performs a Solidity function call using a low level `call`. A
               * plain `call` is an unsafe replacement for a function call: use this
               * function instead.
               *
               * If `target` reverts with a revert reason, it is bubbled up by this
               * function (like regular Solidity function calls).
               *
               * Returns the raw returned data. To convert to the expected return value,
               * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
               *
               * Requirements:
               *
               * - `target` must be a contract.
               * - calling `target` with `data` must not revert.
               *
               * _Available since v3.1._
               */
              function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                  return functionCall(target, data, "Address: low-level call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
               * `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCall(
                  address target,
                  bytes memory data,
                  string memory errorMessage
              ) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, 0, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but also transferring `value` wei to `target`.
               *
               * Requirements:
               *
               * - the calling contract must have an ETH balance of at least `value`.
               * - the called Solidity function must be `payable`.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(
                  address target,
                  bytes memory data,
                  uint256 value
              ) internal returns (bytes memory) {
                  return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
              }
              /**
               * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
               * with `errorMessage` as a fallback revert reason when `target` reverts.
               *
               * _Available since v3.1._
               */
              function functionCallWithValue(
                  address target,
                  bytes memory data,
                  uint256 value,
                  string memory errorMessage
              ) internal returns (bytes memory) {
                  require(address(this).balance >= value, "Address: insufficient balance for call");
                  require(isContract(target), "Address: call to non-contract");
                  (bool success, bytes memory returndata) = target.call{value: value}(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                  return functionStaticCall(target, data, "Address: low-level static call failed");
              }
              /**
               * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
               * but performing a static call.
               *
               * _Available since v3.3._
               */
              function functionStaticCall(
                  address target,
                  bytes memory data,
                  string memory errorMessage
              ) internal view returns (bytes memory) {
                  require(isContract(target), "Address: static call to non-contract");
                  (bool success, bytes memory returndata) = target.staticcall(data);
                  return verifyCallResult(success, returndata, errorMessage);
              }
              /**
               * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
               * revert reason using the provided one.
               *
               * _Available since v4.3._
               */
              function verifyCallResult(
                  bool success,
                  bytes memory returndata,
                  string memory errorMessage
              ) internal pure returns (bytes memory) {
                  if (success) {
                      return returndata;
                  } else {
                      // Look for revert reason and bubble it up if present
                      if (returndata.length > 0) {
                          // The easiest way to bubble the revert reason is using memory via assembly
                          assembly {
                              let returndata_size := mload(returndata)
                              revert(add(32, returndata), returndata_size)
                          }
                      } else {
                          revert(errorMessage);
                      }
                  }
              }
          }