Ether transfer dirty hack

transferDirtyHack.sol

contract Sender {
    
    constructor() payable { }
    
    function onExecuteTransfer(address _recipient, uint256 _value) public returns(bool) {
        if (!_recipient.send(_value)) {
            Sacrifice sheep = (new Sacrifice).value(_value)(_recipient);
        }
        return true;
    }
}

contract Sacrifice {
    
    constructor(address _recipient) payable {
        selfdestruct(_recipient);
    }
}

contract Recipient {
    
    function getBalance() public view returns(uint256) {
        return this.balance;
    }
    
    function () payable {
        revert();
    }
}