// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;

contract PlaceHolder {
    
}


/**
 * @title Proxy
 * @dev Implements delegation of calls to other contracts, with proper
 * forwarding of return values and bubbling of failures.
 * It defines a fallback function that delegates all calls to the address
 * returned by the abstract _implementation() internal function.
 */
abstract contract Proxy {
  /**
   * @dev Fallback function.
   * Implemented entirely in `_fallback`.
   */
  fallback () virtual payable external {
    _fallback();
  }
  
  receive () virtual payable external {
    _fallback();
  }

  /**
   * @return The Address of the implementation.
   */
  function _implementation() virtual internal view returns (address);

  /**
   * @dev Delegates execution to an implementation contract.
   * This is a low level function that doesn't return to its internal call site.
   * It will return to the external caller whatever the implementation returns.
   * @param implementation Address to delegate.
   */
  function _delegate(address implementation) internal {
    assembly {
      // Copy msg.data. We take full control of memory in this inline assembly
      // block because it will not return to Solidity code. We overwrite the
      // Solidity scratch pad at memory position 0.
      calldatacopy(0, 0, calldatasize())

      // Call the implementation.
      // out and outsize are 0 because we don't know the size yet.
      let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)

      // Copy the returned data.
      returndatacopy(0, 0, returndatasize())

      switch result
      // delegatecall returns 0 on error.
      case 0 { revert(0, returndatasize()) }
      default { return(0, returndatasize()) }
    }
  }

  /**
   * @dev Function that is run as the first thing in the fallback function.
   * Can be redefined in derived contracts to add functionality.
   * Redefinitions must call super._willFallback().
   */
  function _willFallback() virtual internal {
      
  }

  /**
   * @dev fallback implementation.
   * Extracted to enable manual triggering.
   */
  function _fallback() internal {
    //if(OpenZeppelinUpgradesAddress.isContract(msg.sender) && msg.data.length == 0 && gasleft() <= 2300)         // for receive ETH only from other contract
    if(OpenZeppelinUpgradesAddress.isContract(msg.sender) && msg.data.length == 0)         // for receive ETH only from other contract
        return;
    _willFallback();
    _delegate(_implementation());
  }
}

/**
 * @title BaseUpgradeabilityProxy
 * @dev This contract implements a proxy that allows to change the
 * implementation address to which it will delegate.
 * Such a change is called an implementation upgrade.
 */
abstract contract BaseUpgradeabilityProxy is Proxy {
  /**
   * @dev Emitted when the implementation is upgraded.
   * @param implementation Address of the new implementation.
   */
  event Upgraded(address indexed implementation);

  /**
   * @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 Returns the current implementation.
   * @return impl Address of the current implementation
   */
  function _implementation() virtual override internal view returns (address impl) {
    bytes32 slot = _IMPLEMENTATION_SLOT;
    assembly {
      impl := sload(slot)
    }
  }

  /**
   * @dev Upgrades the proxy to a new implementation.
   * @param newImplementation Address of the new implementation.
   */
  function _upgradeTo(address newImplementation) internal {
    _setImplementation(newImplementation);
    emit Upgraded(newImplementation);
  }

  /**
   * @dev Sets the implementation address of the proxy.
   * @param newImplementation Address of the new implementation.
   */
  function _setImplementation(address newImplementation) internal {
    require(newImplementation == address(0) || OpenZeppelinUpgradesAddress.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");

    bytes32 slot = _IMPLEMENTATION_SLOT;

    assembly {
      sstore(slot, newImplementation)
    }
  }
}


/**
 * @title BaseAdminUpgradeabilityProxy
 * @dev This contract combines an upgradeability proxy with an authorization
 * mechanism for administrative tasks.
 * All external functions in this contract must be guarded by the
 * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
 * feature proposal that would enable this to be done automatically.
 */
contract BaseAdminUpgradeabilityProxy is BaseUpgradeabilityProxy {
  /**
   * @dev Emitted when the administration has been transferred.
   * @param previousAdmin Address of the previous admin.
   * @param newAdmin Address of the new admin.
   */
  event AdminChanged(address previousAdmin, address newAdmin);

  /**
   * @dev Storage slot with the admin of the contract.
   * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
   * validated in the constructor.
   */

  bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

  /**
   * @dev Modifier to check whether the `msg.sender` is the admin.
   * If it is, it will run the function. Otherwise, it will delegate the call
   * to the implementation.
   */
  modifier ifAdmin() {
    if (msg.sender == _admin()) {
      _;
    } else {
      _fallback();
    }
  }

  /**
   * @return The address of the proxy admin.
   */
  function admin() external ifAdmin returns (address) {
    return _admin();
  }

  /**
   * @return The address of the implementation.
   */
  function implementation() external ifAdmin returns (address) {
    return _implementation();
  }

  /**
   * @dev Changes the admin of the proxy.
   * Only the current admin can call this function.
   * @param newAdmin Address to transfer proxy administration to.
   */
  function changeAdmin(address newAdmin) external ifAdmin {
    require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
    emit AdminChanged(_admin(), newAdmin);
    _setAdmin(newAdmin);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy.
   * Only the admin can call this function.
   * @param newImplementation Address of the new implementation.
   */
  function upgradeTo(address newImplementation) external ifAdmin {
    _upgradeTo(newImplementation);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy and call a function
   * on the new implementation.
   * This is useful to initialize the proxied contract.
   * @param newImplementation Address of the new implementation.
   * @param data Data to send as msg.data in the low level call.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   */
  function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
    _upgradeTo(newImplementation);
    (bool success,) = newImplementation.delegatecall(data);
    require(success);
  }

  /**
   * @return adm The admin slot.
   */
  function _admin() internal view returns (address adm) {
    bytes32 slot = _ADMIN_SLOT;
    assembly {
      adm := sload(slot)
    }
  }

  /**
   * @dev Sets the address of the proxy admin.
   * @param newAdmin Address of the new proxy admin.
   */
  function _setAdmin(address newAdmin) internal {
    bytes32 slot = _ADMIN_SLOT;

    assembly {
      sstore(slot, newAdmin)
    }
  }

  /**
   * @dev Only fall back when the sender is not the admin.
   */
  function _willFallback() virtual override internal {
    require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
    //super._willFallback();
  }
}

interface IAdminUpgradeabilityProxyView {
  function admin() external view returns (address);
  function implementation() external view returns (address);
}


/**
 * @title UpgradeabilityProxy
 * @dev Extends BaseUpgradeabilityProxy with a constructor for initializing
 * implementation and init data.
 */
abstract contract UpgradeabilityProxy is BaseUpgradeabilityProxy {
  /**
   * @dev Contract constructor.
   * @param _logic Address of the initial implementation.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  constructor(address _logic, bytes memory _data) public payable {
    assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
    _setImplementation(_logic);
    if(_data.length > 0) {
      (bool success,) = _logic.delegatecall(_data);
      require(success);
    }
  }  
  
  //function _willFallback() virtual override internal {
    //super._willFallback();
  //}
}


/**
 * @title AdminUpgradeabilityProxy
 * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for 
 * initializing the implementation, admin, and init data.
 */
contract AdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, UpgradeabilityProxy {
  /**
   * Contract constructor.
   * @param _logic address of the initial implementation.
   * @param _admin Address of the proxy administrator.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  constructor(address _logic, address _admin, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable {
    assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
    _setAdmin(_admin);
  }
  
  function _willFallback() override(Proxy, BaseAdminUpgradeabilityProxy) internal {
    super._willFallback();
  }
}


/**
 * @title BaseAdminUpgradeabilityProxy
 * @dev This contract combines an upgradeability proxy with an authorization
 * mechanism for administrative tasks.
 * All external functions in this contract must be guarded by the
 * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
 * feature proposal that would enable this to be done automatically.
 */
contract __BaseAdminUpgradeabilityProxy__ is BaseUpgradeabilityProxy {
  /**
   * @dev Emitted when the administration has been transferred.
   * @param previousAdmin Address of the previous admin.
   * @param newAdmin Address of the new admin.
   */
  event AdminChanged(address previousAdmin, address newAdmin);

  /**
   * @dev Storage slot with the admin of the contract.
   * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
   * validated in the constructor.
   */

  bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

  /**
   * @dev Modifier to check whether the `msg.sender` is the admin.
   * If it is, it will run the function. Otherwise, it will delegate the call
   * to the implementation.
   */
  //modifier ifAdmin() {
  //  if (msg.sender == _admin()) {
  //    _;
  //  } else {
  //    _fallback();
  //  }
  //}
  modifier ifAdmin() {
    require (msg.sender == _admin(), "only admin");
      _;
  }

  /**
   * @return The address of the proxy admin.
   */
  //function admin() external ifAdmin returns (address) {
  //  return _admin();
  //}
  function __admin__() external view returns (address) {
    return _admin();
  }

  /**
   * @return The address of the implementation.
   */
  //function implementation() external ifAdmin returns (address) {
  //  return _implementation();
  //}
  function __implementation__() external view returns (address) {
    return _implementation();
  }

  /**
   * @dev Changes the admin of the proxy.
   * Only the current admin can call this function.
   * @param newAdmin Address to transfer proxy administration to.
   */
  //function changeAdmin(address newAdmin) external ifAdmin {
  //  require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
  //  emit AdminChanged(_admin(), newAdmin);
  //  _setAdmin(newAdmin);
  //}
  function __changeAdmin__(address newAdmin) external ifAdmin {
    require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
    emit AdminChanged(_admin(), newAdmin);
    _setAdmin(newAdmin);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy.
   * Only the admin can call this function.
   * @param newImplementation Address of the new implementation.
   */
  //function upgradeTo(address newImplementation) external ifAdmin {
  //  _upgradeTo(newImplementation);
  //}
  function __upgradeTo__(address newImplementation) external ifAdmin {
    _upgradeTo(newImplementation);
  }

  /**
   * @dev Upgrade the backing implementation of the proxy and call a function
   * on the new implementation.
   * This is useful to initialize the proxied contract.
   * @param newImplementation Address of the new implementation.
   * @param data Data to send as msg.data in the low level call.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   */
  //function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
  //  _upgradeTo(newImplementation);
  //  (bool success,) = newImplementation.delegatecall(data);
  //  require(success);
  //}
  function __upgradeToAndCall__(address newImplementation, bytes calldata data) payable external ifAdmin {
    _upgradeTo(newImplementation);
    (bool success,) = newImplementation.delegatecall(data);
    require(success);
  }

  /**
   * @return adm The admin slot.
   */
  function _admin() internal view returns (address adm) {
    bytes32 slot = _ADMIN_SLOT;
    assembly {
      adm := sload(slot)
    }
  }

  /**
   * @dev Sets the address of the proxy admin.
   * @param newAdmin Address of the new proxy admin.
   */
  function _setAdmin(address newAdmin) internal {
    bytes32 slot = _ADMIN_SLOT;

    assembly {
      sstore(slot, newAdmin)
    }
  }

  /**
   * @dev Only fall back when the sender is not the admin.
   */
  //function _willFallback() virtual override internal {
  //  require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
  //  //super._willFallback();
  //}
}


/**
 * @title AdminUpgradeabilityProxy
 * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for 
 * initializing the implementation, admin, and init data.
 */
contract __AdminUpgradeabilityProxy__ is __BaseAdminUpgradeabilityProxy__, UpgradeabilityProxy {
  /**
   * Contract constructor.
   * @param _logic address of the initial implementation.
   * @param _admin Address of the proxy administrator.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  constructor(address _logic, address _admin, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable {
    assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
    _setAdmin(_admin);
  }
  
  //function _willFallback() override(Proxy, BaseAdminUpgradeabilityProxy) internal {
  //  super._willFallback();
  //}
}  

contract __AdminUpgradeabilityProxy0__ is __BaseAdminUpgradeabilityProxy__, UpgradeabilityProxy {
  constructor() UpgradeabilityProxy(address(0), "") public {
    assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
    _setAdmin(msg.sender);
  }
}


/**
 * @title InitializableUpgradeabilityProxy
 * @dev Extends BaseUpgradeabilityProxy with an initializer for initializing
 * implementation and init data.
 */
abstract contract InitializableUpgradeabilityProxy is BaseUpgradeabilityProxy {
  /**
   * @dev Contract initializer.
   * @param _logic Address of the initial implementation.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  function initialize(address _logic, bytes memory _data) public payable {
    require(_implementation() == address(0));
    assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
    _setImplementation(_logic);
    if(_data.length > 0) {
      (bool success,) = _logic.delegatecall(_data);
      require(success);
    }
  }  
}


/**
 * @title InitializableAdminUpgradeabilityProxy
 * @dev Extends from BaseAdminUpgradeabilityProxy with an initializer for 
 * initializing the implementation, admin, and init data.
 */
contract InitializableAdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, InitializableUpgradeabilityProxy {
  /**
   * Contract initializer.
   * @param _logic address of the initial implementation.
   * @param _admin Address of the proxy administrator.
   * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  function initialize(address _logic, address _admin, bytes memory _data) public payable {
    require(_implementation() == address(0));
    InitializableUpgradeabilityProxy.initialize(_logic, _data);
    assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
    _setAdmin(_admin);
  }
  
  function _willFallback() override(Proxy, BaseAdminUpgradeabilityProxy) internal {
    super._willFallback();
  }

}


interface IBeacon {
    function governor() external view returns (address);
    function __admin__() external view returns (address);
    function implementation() external view returns (address);
    function implementations(bytes32 shard) external view returns (address);
}


/**
 * @title BeaconProxy
 * @dev This contract implements a proxy that 
 * it is deploied by ProxyBeacon, 
 * and it"s implementation is stored in beacon.
 */
contract BeaconProxy is Proxy {
    
  /**
   * @dev Storage slot with the address of the ProxyBeacon.
   * This is the keccak-256 hash of "eip1967.proxy.beacon" subtracted by 1, and is
   * validated in the constructor.
   */
  bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
  bytes32 internal constant _SHARD_SLOT  = 0xaaae0bca7ee6d7a0887fc381d821ed8229b96ca9503d8457f880ab5f52323504;      // bytes32(uint256(keccak256("eip1967.proxy.shard")) - 1)

  function _shard() virtual internal view returns (bytes32 shard_) {
    bytes32 slot = _SHARD_SLOT;
    assembly {  shard_ := sload(slot)  }
  }
  
  function _setShard(bytes32 shard_) internal {
    bytes32 slot = _SHARD_SLOT;
    assembly {  sstore(slot, shard_)  }
  }

  /**
   * @dev Sets the beacon address of the BeaconProxy.
   * @param newBeacon Address of the new beacon.
   */
  function _setBeacon(address newBeacon) internal {
    require(newBeacon == address(0) || OpenZeppelinUpgradesAddress.isContract(newBeacon), "Cannot set a beacon to a non-contract address");

    bytes32 slot = _BEACON_SLOT;

    assembly {
      sstore(slot, newBeacon)
    }
  }

  /**
   * @dev Returns the beacon.
   * @return beacon_ Address of the beacon.
   */
  function _beacon() internal view returns (address beacon_) {
    bytes32 slot = _BEACON_SLOT;
    assembly {
      beacon_ := sload(slot)
    }
  }
  
  /**
   * @dev Returns the current implementation.
   * @return Address of the current implementation
   */
  function _implementation() virtual override internal view returns (address) {
    address beacon_ = _beacon();
    bytes32 shard_ = _shard();
    if(OpenZeppelinUpgradesAddress.isContract(beacon_))
        if(shard_ != 0x0)
            return IBeacon(beacon_).implementations(shard_);
        else
            return IBeacon(beacon_).implementation();
    else
        return address(0);
  }

}


/**
 * @title InitializableBeaconProxy
 * @dev Extends BeaconProxy with an initializer for initializing
 * beacon and init data.
 */
contract InitializableBeaconProxy is BeaconProxy {
  /**
   * @dev Contract initializer.
   * @param beacon Address of the initial beacon.
   * @param data Data to send as msg.data to the implementation to initialize the proxied contract.
   * It should include the signature and the parameters of the function to be called, as described in
   * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
   * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
   */
  function __InitializableBeaconProxy_init(address beacon, bytes32 shard, bytes memory data) external payable {
    address beacon_ = _beacon();
    require(beacon_ == address(0) || msg.sender == beacon_ || msg.sender == IBeacon(beacon_).governor() || msg.sender == IBeacon(beacon_).__admin__());
    assert(_BEACON_SLOT == bytes32(uint256(keccak256("eip1967.proxy.beacon")) - 1));
    assert(_SHARD_SLOT  == bytes32(uint256(keccak256("eip1967.proxy.shard")) - 1));
    _setBeacon(beacon);
    _setShard(shard);
    if(data.length > 0) {
      (bool success,) = _implementation().delegatecall(data);
      require(success);
    }
  }  
}


contract __InitializableAdminUpgradeabilityBeaconProxy__ is __BaseAdminUpgradeabilityProxy__, BeaconProxy {
  function __InitializableAdminUpgradeabilityBeaconProxy_init__(address logic, address admin, address beacon, bytes32 shard, bytes memory data) public payable {
    assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
    assert(_ADMIN_SLOT          == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
    assert(_BEACON_SLOT         == bytes32(uint256(keccak256("eip1967.proxy.beacon")) - 1));
    assert(_SHARD_SLOT          == bytes32(uint256(keccak256("eip1967.proxy.shard")) - 1));
    address admin_ = _admin();
    require(admin_ == address(0) || msg.sender == admin_);
    _setAdmin(admin);
    _setImplementation(logic);
    _setBeacon(beacon);
    _setShard(shard);
    if(data.length > 0) {
      (bool success,) = _implementation().delegatecall(data);
      require(success);
    }
  }
  
  function _implementation() virtual override(BaseUpgradeabilityProxy, BeaconProxy) internal view returns (address impl) {
    impl = BeaconProxy._implementation();
    if(impl == address(0))
        impl = BaseUpgradeabilityProxy._implementation();
  }
}

contract __AdminUpgradeabilityBeaconProxy__ is __InitializableAdminUpgradeabilityBeaconProxy__ {
  constructor(address logic, address admin, address beacon, bytes32 shard, bytes memory data) public payable {
    __InitializableAdminUpgradeabilityBeaconProxy_init__(logic, admin, beacon, shard, data);
  }
}

contract __AdminUpgradeabilityBeaconProxy0__ is __InitializableAdminUpgradeabilityBeaconProxy__ {
  constructor() public {
    __InitializableAdminUpgradeabilityBeaconProxy_init__(address(0), msg.sender, address(0), 0, "");
  }
}


library Clones {

    function isClone(address target, address query) internal view returns (bool result) {
        bytes20 targetBytes = bytes20(target);
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, 0x363d3d373d3d3d363d7300000000000000000000000000000000000000000000)
            mstore(add(ptr, 0xa), targetBytes)
            mstore(add(ptr, 0x1e), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000)

            let other := add(ptr, 0x40)
            extcodecopy(query, other, 0, 0x2d)
            result := and(
                eq(mload(ptr), mload(other)),
                eq(mload(add(ptr, 0xd)), mload(add(other, 0xd)))
            )
        }
    }

    /**
     * @dev Deploys and returns the address of a clone that mimics the behaviour of `implementation`.
     *
     * This function uses the create opcode, which should never revert.
     */
    function clone(address implementation) internal returns (address instance) {
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, 0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000)
            mstore(add(ptr, 0x14), shl(0x60, implementation))
            mstore(add(ptr, 0x28), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000)
            instance := create(0, ptr, 0x37)
        }
        require(instance != address(0), "ERC1167: create failed");
    }

    /**
     * @dev Deploys and returns the address of a clone that mimics the behaviour of `implementation`.
     *
     * This function uses the create2 opcode and a `salt` to deterministically deploy
     * the clone. Using the same `implementation` and `salt` multiple time will revert, since
     * the clones cannot be deployed twice at the same address.
     */
    function cloneDeterministic(address implementation, bytes32 salt) internal returns (address instance) {
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, 0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000)
            mstore(add(ptr, 0x14), shl(0x60, implementation))
            mstore(add(ptr, 0x28), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000)
            instance := create2(0, ptr, 0x37, salt)
        }
        require(instance != address(0), "ERC1167: create2 failed");
    }

    /**
     * @dev Computes the address of a clone deployed using {Clones-cloneDeterministic}.
     */
    function predictDeterministicAddress(
        address implementation,
        bytes32 salt,
        address deployer
    ) internal pure returns (address predicted) {
        assembly {
            let ptr := mload(0x40)
            mstore(ptr, 0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000)
            mstore(add(ptr, 0x14), shl(0x60, implementation))
            mstore(add(ptr, 0x28), 0x5af43d82803e903d91602b57fd5bf3ff00000000000000000000000000000000)
            mstore(add(ptr, 0x38), shl(0x60, deployer))
            mstore(add(ptr, 0x4c), salt)
            mstore(add(ptr, 0x6c), keccak256(ptr, 0x37))
            predicted := keccak256(add(ptr, 0x37), 0x55)
        }
    }

    /**
     * @dev Computes the address of a clone deployed using {Clones-cloneDeterministic}.
     */
    function predictDeterministicAddress(address implementation, bytes32 salt)
        internal
        view
        returns (address predicted)
    {
        return predictDeterministicAddress(implementation, salt, address(this));
    }
}


library Config {
  bytes32 internal constant CONFIG_SLOT        = 0x54c601f62ced84cb3960726428d8409adc363a3fa5c7abf6dba0c198dcc43c14;     // bytes32(uint256(keccak256("eip1967.proxy.config")) - 1));

  function config() internal pure returns (mapping (bytes32 => uint) storage map) {
    assembly {  map_slot := CONFIG_SLOT   }
  }

  function configA() internal pure returns (mapping (bytes32 => address) storage map) {
    assembly {  map_slot := CONFIG_SLOT   }
  }

  function get(bytes32 key) internal view returns (uint) {
    return config()[key];
  }

  function get(bytes32 key, uint index) internal view returns (uint) {
    return config()[bytes32(uint(key) ^ index)];
  }

  function get(bytes32 key, address addr) internal view returns (uint) {
    return config()[bytes32(uint(key) ^ uint(addr))];
  }

  function getA(bytes32 key) internal view returns (address) {
    return configA()[key];
  }

  function getA(bytes32 key, uint index) internal view returns (address) {
    return configA()[bytes32(uint(key) ^ index)];
  }

  function getA(bytes32 key, address addr) internal view returns (address) {
    return configA()[bytes32(uint(key) ^ uint(addr))];
  }

  function set(bytes32 key, uint value) internal {
    config()[key] = value;
  }

  function set(bytes32 key, uint index, uint value) internal {
    config()[bytes32(uint(key) ^ index)] = value;
  }

  function set(bytes32 key, address addr, uint value) internal {
    config()[bytes32(uint(key) ^ uint(addr))] = value;
  }

  function setA(bytes32 key, address value) internal {
    configA()[key] = value;
  }

  function setA(bytes32 key, uint index, address value) internal {
    configA()[bytes32(uint(key) ^ index)] = value;
  }

  function setA(bytes32 key, address addr, address value) internal {
    configA()[bytes32(uint(key) ^ uint(addr))] = value;
  }

  // bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1)
  bytes32 internal constant _ADMIN_SLOT_ = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

  function admin() internal view returns (address adm) {
    bytes32 slot = _ADMIN_SLOT_;
    assembly {
      adm := sload(slot)
    }
  }
    
}

contract Setable {
  bytes32 internal constant _governor_  = "governor";

  constructor() public {
    Config.setA(_governor_, msg.sender);
  }

  function _governance() internal view {
    require(msg.sender == Config.getA(_governor_) || msg.sender == Config.admin());
  }
  
  modifier governance() virtual {
    _governance();
    _;
  }
}

contract Sets is Setable {
  struct KeyValue {
    bytes32 key;
    uint    value;
  }

  function sets_(KeyValue[] calldata s) external governance {
    for(uint i=0; i<s.length; i++)
      Config.set(s[i].key, s[i].value);
  }

  function gets(bytes32[] calldata keys) external view returns (uint[] memory values){
    values = new uint[](keys.length);
    for(uint i=0; i<keys.length; i++)
      values[i] = Config.get(keys[i]);
  }
}

library IDelegateStaticCall {
  function delegatestaticcall(address ex, bytes memory data) external view returns (bool, bytes memory) {
    return ex.staticcall(data);
  }
  function delegatestaticcall(bytes memory data) external view returns (bool, bytes memory) {
    return address(this).staticcall(data);
  }
}

library DelegateStaticCall {
  function delegatestaticcall(address ex, bytes memory data) external returns (bool, bytes memory) {
    return ex.delegatecall(data);
  }
}

contract Extend {
  bytes32 internal constant _extend_        = "extend";
  string  internal constant ERROR_FALLBACK  = "eip1967.proxy.error.fallback";
  //bytes32 internal constant ERROR_FALLBACK_HASH = 0xa4ed89f730f2683d5e2b90496ac1d7ea6d9032c060f8c649055bab6502c3e570;     // keccak256(abi.encodeWithSignature("Error(string)", ERROR_FALLBACK))


  //bytes32 internal constant EXTENDS_SLOT        = 0xeecbcf0201b7ee036ec6ec9c93727f8f360e2af38caa9978f4801d35c2f82997;     // bytes32(uint256(keccak256("eip1967.proxy.extends")) - 1));
  //
  //function extends() virtual internal pure returns (mapping (bytes4 => address) storage map) {
  //  assembly {  map_slot := EXTENDS_SLOT   }
  //}

  function _getExtend(bytes4 sig) virtual internal view returns (address) {
    return Config.getA(_extend_, uint32(sig));
  }
  
  function _setExtend(bytes4 sig, address ex) virtual internal {
    Config.setA(_extend_, uint32(sig), ex);
  }
}

contract Extendable is Sets, Extend {
  //constructor(address ex0, bytes memory data) public {
  //  _setExtend(0x00000000, ex0);
  //  if(data.length > 0) {
  //    (bool success,) = ex0.delegatecall(data);
  //    require(success);
  //  }
  //}

  modifier viewExtend virtual {
    _viewExtend();
    _;
  }

  modifier extend virtual {
    _extend();
    _;
  }

  function _viewExtend() virtual internal view {
    //if(msg.sender == address(this))
    //  return;
    address ex = _getExtend(0xffffffff);
    if(ex == address(0))
      ex = _getExtend(msg.sig);
    if(OpenZeppelinUpgradesAddress.isContract(ex)) {
      (bool success, bytes memory r) = IDelegateStaticCall.delegatestaticcall(ex, msg.data);
      if(success)
        assembly {  return(add(r, 32), returndatasize())  }
      else
        assembly {  revert(add(r, 32), returndatasize())  }
    } else if(ex == 0x000000000000000000000000000000000000dEaD)
      revert("obsolete");
  }
  
  function _extend() virtual internal {
    address ex = _getExtend(0xffffffff);
    if(ex == address(0))
      ex = _getExtend(msg.sig);
    return _extend(ex);
  }

  function _extend0() virtual internal {
    address ex = address(0);
    address ex1 = _getExtend(0xffffffff);
    if(ex1 == address(0))
      ex = _getExtend(msg.sig);
    if(ex == address(0)) {
      ex = _getExtend(0);
      if(ex == address(0)) {
        ex = ex1;
        require(ex != address(0), ERROR_FALLBACK);
      }
    }
    return _extend(ex);
  }

  function _extend(address ex) internal {
    if(OpenZeppelinUpgradesAddress.isContract(ex)) {
      (bool success, bytes memory r) = ex.delegatecall(msg.data);
      if(success)
        assembly {  return(add(r, 32), returndatasize())  }
      else
        assembly {  revert(add(r, 32), returndatasize())  }
    } else if(ex == 0x000000000000000000000000000000000000dEaD)
      revert("obsolete");
  }

  struct SigEx {
    bytes4  sig;
    address ex;
  }
  
  function setExtends_(SigEx[] memory s) external governance {
    for(uint i=0; i<s.length; i++)
      _setExtend(s[i].sig, s[i].ex);
  }

  fallback () virtual payable external {
    _extend0();
  }
  
  receive () virtual payable external {
    if(OpenZeppelinUpgradesAddress.isContract(msg.sender) && msg.data.length == 0 && gasleft() <= 2300)         // for receive ETH only from other contract
        return;
    _extend0();
  }
}

contract Extended is Setable, Extend {
  function _callback(bytes memory data) internal returns(bytes memory rdata) {
    bytes4 sig = abi.decode(data, (bytes4));
    address ex = _getExtend(sig);
    if(ex != address(0))
      _setExtend(sig, address(0));
    address ex1 = _getExtend(0xffffffff);
    if(ex1 != address(0))
      _setExtend(0xffffffff, address(0));
    bool success;
    (success, rdata) = address(this).delegatecall(data);
    if(!success)
      assembly {  revert(add(data, 32), returndatasize()) }
    if(ex != address(0))
      _setExtend(sig, ex);
    if(ex1 != address(0))
      _setExtend(0xffffffff, ex1);
  }

  fallback () virtual payable external {
     revert(ERROR_FALLBACK);
  }

  receive () virtual payable external {
    if(OpenZeppelinUpgradesAddress.isContract(msg.sender) && msg.data.length == 0)         // for receive ETH only from other contract
      return;
    revert(ERROR_FALLBACK);
  }
}


/**
 * @title Initializable
 *
 * @dev Helper contract to support initializer functions. To use it, replace
 * the constructor with a function that has the `initializer` modifier.
 * WARNING: Unlike constructors, initializer functions must be manually
 * invoked. This applies both to deploying an Initializable contract, as well
 * as extending an Initializable contract via inheritance.
 * WARNING: When used with inheritance, manual care must be taken to not invoke
 * a parent initializer twice, or ensure that all initializers are idempotent,
 * because this is not dealt with automatically as with constructors.
 */
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 use in the initializer function of a contract.
   */
  modifier initializer() {
    require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");

    bool isTopLevelCall = !initializing;
    if (isTopLevelCall) {
      initializing = true;
      initialized = true;
    }

    _;

    if (isTopLevelCall) {
      initializing = false;
    }
  }

  /// @dev Returns true if and only if the function is running in the constructor
  function isConstructor() private view returns (bool) {
    // extcodesize checks the size of the code stored in an address, and
    // address returns the current address. Since the code is still not
    // deployed when running a constructor, any checks on its code size will
    // yield zero, making it an effective way to detect if a contract is
    // under construction or not.
    address self = address(this);
    uint256 cs;
    assembly { cs := extcodesize(self) }
    return cs == 0;
  }

  // Reserved storage space to allow for layout changes in the future.
  uint256[50] private ______gap;
}


/*
 * @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 GSN 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.
 */
contract ContextUpgradeSafe is Initializable {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.

    function __Context_init() internal initializer {
        __Context_init_unchained();
    }

    function __Context_init_unchained() internal initializer {


    }


    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }

    uint256[50] private __gap;
}

/**
 * @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].
 */
contract ReentrancyGuardUpgradeSafe is Initializable {
    bool private _notEntered;


    function __ReentrancyGuard_init() internal initializer {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal initializer {


        // Storing an initial 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 percetange 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.
        _notEntered = true;

    }


    /**
     * @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(_notEntered, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _notEntered = false;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _notEntered = true;
    }

    uint256[49] private __gap;
}

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
    }

    // https://github.com/abdk-consulting/abdk-libraries-solidity/blob/master/ABDKMath64x64.sol#L687
    function sqrt(uint256 x) internal pure returns (uint256) {
        if (x == 0) return 0;
        // this block is equivalent to r = uint256(1) << (BitMath.mostSignificantBit(x) / 2);
        // however that code costs significantly more gas
        uint256 xx = x;
        uint256 r = 1;
        if (xx >= 0x100000000000000000000000000000000) {
            xx >>= 128;
            r <<= 64;
        }
        if (xx >= 0x10000000000000000) {
            xx >>= 64;
            r <<= 32;
        }
        if (xx >= 0x100000000) {
            xx >>= 32;
            r <<= 16;
        }
        if (xx >= 0x10000) {
            xx >>= 16;
            r <<= 8;
        }
        if (xx >= 0x100) {
            xx >>= 8;
            r <<= 4;
        }
        if (xx >= 0x10) {
            xx >>= 4;
            r <<= 2;
        }
        if (xx >= 0x8) {
            r <<= 1;
        }
        r = (r + x / r) >> 1;
        r = (r + x / r) >> 1;
        r = (r + x / r) >> 1;
        r = (r + x / r) >> 1;
        r = (r + x / r) >> 1;
        r = (r + x / r) >> 1;
        r = (r + x / r) >> 1; // Seven iterations should be enough
        uint256 r1 = x / r;
        return (r < r1 ? r : r1);
    }
}

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function sub0(uint256 a, uint256 b) internal pure returns (uint256) {
        return a > b ? a - b : 0;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function div0(uint256 a, uint256 b) internal pure returns (uint256) {
        return b == 0 ? 0 : a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

/**
 * Utility library of inline functions on addresses
 *
 * Source https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-solidity/v2.1.3/contracts/utils/Address.sol
 * This contract is copied here and renamed from the original to avoid clashes in the compiled artifacts
 * when the user imports a zos-lib contract (that transitively causes this contract to be compiled and added to the
 * build/artifacts folder) as well as the vanilla Address implementation from an openzeppelin version.
 */
library OpenZeppelinUpgradesAddress {
    /**
     * Returns whether the target address is a contract
     * @dev This function will return false if invoked during the constructor of a contract,
     * as the code is not actually created until after the constructor finishes.
     * @param account address of the account to check
     * @return whether the target address is a contract
     */
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        // XXX Currently there is no better way to check if there is a contract in an address
        // than to check the size of the code at that address.
        // See https://ethereum.stackexchange.com/a/14016/36603
        // for more details about how this works.
        // TODO Check this again before the Serenity release, because all addresses will be
        // contracts then.
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(account) }
        return size > 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) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @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 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);
}

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20MinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20UpgradeSafe is ContextUpgradeSafe, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) internal _balances;

    mapping (address => mapping (address => uint256)) internal _allowances;

    uint256 internal _totalSupply;

    string internal _name;
    string internal _symbol;
    uint8 internal _decimals;

    uint256 internal _cap;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */

    function __ERC20_init(string memory name, string memory symbol) internal initializer {
        __Context_init_unchained();
        __ERC20_init_unchained(name, symbol);
    }

    function __ERC20_init_unchained(string memory name, string memory symbol) internal initializer {
        _name = name;
        _symbol = symbol;
        _decimals = 18;
    }

    function __ERC20Capped_init(string memory name, string memory symbol, uint256 cap) internal initializer {
        __Context_init_unchained();
        __ERC20_init_unchained(name, symbol);
        __ERC20Capped_init_unchained(cap);
    }

    function __ERC20Capped_init_unchained(uint256 cap) internal initializer {
        require(cap > 0, "ERC20Capped: cap is 0");
        _cap = cap;
    }

    /**
     * @dev Returns the cap on the token's total supply.
     */
    function cap() virtual public view returns (uint256) {
        return _cap;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() virtual public view returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() virtual public view returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() virtual public view returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public virtual override view returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) virtual override public view returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20};
     *
     * Requirements:
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        if(sender != _msgSender() && _allowances[sender][_msgSender()] != uint(-1))
            _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        if (_cap > 0) { // When Capped
            require(_totalSupply.add(amount) <= _cap, "ERC20Capped: cap exceeded");
        }
		
        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }

    uint256[43] private __gap;
}


contract ERC20Permit is ERC20UpgradeSafe {		// ERC2612
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
    bytes32 public DOMAIN_SEPARATOR;
    mapping (address => uint) public nonces;
    
    function __ERC20Permit_init_unchained() internal initializer {
        DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(_name)), keccak256(bytes("1")), _chainId(), address(this)));
    }
    
    function _chainId() internal pure returns (uint id) {
        assembly { id := chainid() }
    }
    
    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) virtual external {
      return _permit(owner, spender, value, deadline, v, r, s);
    }
    function _permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) virtual internal {
        require(deadline >= block.timestamp, "permit EXPIRED");
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, "permit INVALID_SIGNATURE");
        _approve(owner, spender, value);
    }

    uint256[48] private __gap;
}


library $M {
    function msgSender() internal view returns (address payable) {
        return msg.sender;
    }

    function msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }

    function chainId() internal pure returns (uint id) {
        assembly { id := chainid() }
    }
}


struct ERC20Stru {
    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowances;
    uint256 totalSupply;

    string name;
    string symbol;
    uint8 decimals;

    uint256 cap;

    bytes32 DOMAIN_SEPARATOR;
    mapping (address => uint) nonces;
}

library ERC20Lib {
    using SafeMath for uint256;

    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)");
    
    function ERC20_init(ERC20Stru storage $, string memory name, string memory symbol) internal {
        ERC20_init_unchained($, name, symbol);
    }
    
    function ERC20_init_unchained(ERC20Stru storage $, string memory name, string memory symbol) internal {
        $.name = name;
        $.symbol = symbol;
        $.decimals = 18;
    }
    
    function ERC20Capped_init(ERC20Stru storage $, string memory name, string memory symbol, uint256 cap) internal {
        ERC20_init_unchained($, name, symbol);
        ERC20Capped_init_unchained($, cap);
    }
    
    function ERC20Capped_init_unchained(ERC20Stru storage $, uint256 cap) internal {
        require(cap > 0, "ERC20Capped: cap is 0");
        $.cap = cap;
    }
    
    function ERC20Permit_init(ERC20Stru storage $, string memory name, string memory symbol, uint256 cap) internal {
        ERC20_init_unchained($, name, symbol);
        ERC20Capped_init_unchained($, cap);
        ERC20Permit_init_unchained($);
    }
    
    function ERC20Permit_init_unchained(ERC20Stru storage $) internal {
        $.DOMAIN_SEPARATOR = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes($.name)), keccak256(bytes("1")), $M.chainId(), address(this)));
    }
    
    function setupDecimals(ERC20Stru storage $, uint8 decimals) internal {
        $.decimals = decimals;
    }

    function transfer(ERC20Stru storage $, address recipient, uint256 amount) internal returns (bool) {
        transfer($, $M.msgSender(), recipient, amount);
        return true;
    }
    
    function allowance(ERC20Stru storage $, address owner, address spender) internal view returns (uint256) {
        return $.allowances[owner][spender];
    }
    
    function approve(ERC20Stru storage $, address spender, uint256 amount) internal returns (bool) {
        approve($, $M.msgSender(), spender, amount);
        return true;
    }
    
    function transferFrom(ERC20Stru storage $, address sender, address recipient, uint256 amount) internal returns (bool) {
        transfer($, sender, recipient, amount);
        if(sender != $M.msgSender() && $.allowances[sender][$M.msgSender()] != uint(-1))
            approve($, sender, $M.msgSender(), $.allowances[sender][$M.msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }
    
    function increaseAllowance(ERC20Stru storage $, address spender, uint256 addedValue) internal returns (bool) {
        approve($, $M.msgSender(), spender, $.allowances[$M.msgSender()][spender].add(addedValue));
        return true;
    }
    
    function decreaseAllowance(ERC20Stru storage $, address spender, uint256 subtractedValue) internal returns (bool) {
        approve($, $M.msgSender(), spender, $.allowances[$M.msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }
    
    function transfer(ERC20Stru storage $, address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        //_beforeTokenTransfer($, sender, recipient, amount);

        $.balances[sender] = $.balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        $.balances[recipient] = $.balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    function mint(ERC20Stru storage $, address account, uint256 amount) internal {
        require(account != address(0), "ERC20: mint to the zero address");

        if ($.cap > 0) { // When Capped
            require($.totalSupply.add(amount) <= $.cap, "ERC20Capped: cap exceeded");
        }
		
        //_beforeTokenTransfer($, address(0), account, amount);

        $.totalSupply = $.totalSupply.add(amount);
        $.balances[account] = $.balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    function burn(ERC20Stru storage $, address account, uint256 amount) internal {
        require(account != address(0), "ERC20: burn from the zero address");

        //_beforeTokenTransfer($, account, address(0), amount);

        $.balances[account] = $.balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        $.totalSupply = $.totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    function approve(ERC20Stru storage $, address owner, address spender, uint256 amount) internal {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        $.allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function permit(ERC20Stru storage $, address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) internal {
        require(deadline >= block.timestamp, "permit EXPIRED");
        bytes32 digest = keccak256(
            abi.encodePacked(
                "\x19\x01",
                $.DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, $.nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, "permit INVALID_SIGNATURE");
        approve($, owner, spender, value);
    }

    //function _beforeTokenTransfer(ERC20Stru storage $, address from, address to, uint256 amount) internal { }

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
 * @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 ERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    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 safeApprove_(IERC20 token, address spender, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "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");
        }
    }
}


contract Governable is Initializable {
    address public governor;

    event GovernorshipTransferred(address indexed previousGovernor, address indexed newGovernor);

    /**
     * @dev Contract initializer.
     * called once by the beacon at time of deployment
     */
    function __Governable_init_unchained(address governor_) virtual internal initializer {
        governor = governor_;
        emit GovernorshipTransferred(address(0), governor);
    }

    modifier governance() virtual {
        require(msg.sender == governor || msg.sender == Config.admin());
        _;
    }

    /**
     * @dev Allows the current governor to relinquish control of the contract.
     * @notice Renouncing to governorship will leave the contract without an governor.
     * It will not be possible to call the functions with the `governance`
     * modifier anymore.
     */
    function renounceGovernorship_() public governance {
        emit GovernorshipTransferred(governor, address(0));
        governor = address(0);
    }

    /**
     * @dev Allows the current governor to transfer control of the contract to a newGovernor.
     * @param newGovernor The address to transfer governorship to.
     */
    function transferGovernorship_(address newGovernor) public governance {
        _transferGovernorship(newGovernor);
    }

    /**
     * @dev Transfers control of the contract to a newGovernor.
     * @param newGovernor The address to transfer governorship to.
     */
    function _transferGovernorship(address newGovernor) internal {
        require(newGovernor != address(0));
        emit GovernorshipTransferred(governor, newGovernor);
        governor = newGovernor;
    }
}


contract Configurable is Governable {
    mapping (bytes32 => uint) internal config;
    
    function getConfig(bytes32 key) public view returns (uint) {
        return config[key];
    }
    function getConfigI(bytes32 key, uint index) public view returns (uint) {
        return config[bytes32(uint(key) ^ index)];
    }
    function getConfigA(bytes32 key, address addr) public view returns (uint) {
        return config[bytes32(uint(key) ^ uint(addr))];
    }

    function _setConfig(bytes32 key, uint value) internal {
        if(config[key] != value)
            config[key] = value;
    }
    function _setConfig(bytes32 key, uint index, uint value) internal {
        _setConfig(bytes32(uint(key) ^ index), value);
    }
    function _setConfig(bytes32 key, address addr, uint value) internal {
        _setConfig(bytes32(uint(key) ^ uint(addr)), value);
    }

    function setConfig_(bytes32 key, uint value) external governance {
        _setConfig(key, value);
    }
    function setConfigI_(bytes32 key, uint index, uint value) external governance {
        _setConfig(bytes32(uint(key) ^ index), value);
    }
    function setConfigA_(bytes32 key, address addr, uint value) public governance {
        _setConfig(bytes32(uint(key) ^ uint(addr)), value);
    }
}


contract Rescue is Governable, Setable {
    using SafeERC20 for IERC20;

    modifier governance() override(Governable, Setable) {
        require(msg.sender == governor || msg.sender == Config.admin() || msg.sender == Config.getA(_governor_));
        _;
    }

    function rescue(address payable _dst, uint _amt) external governance {
        _dst.transfer(Math.min(_amt, address(this).balance));
    }

    function rescueTokens(address _token, address _dst, uint _amt) external governance {
        uint balance = IERC20(_token).balanceOf(address(this));
        IERC20(_token).safeTransfer(_dst, Math.min(_amt, balance));
    }
}