inheritance.sol

contract Owner {
    address owner;
    function setOwner() public { 
        owner = msg.sender; 
    }
}

contract Suicide is Owner {
    function destroy() public {
        if (msg.sender == owner) selfdestruct(payable(owner));
    }
}

contract EndGame is Suicide {
    function kill() public { 
        super.destroy(); // Calls kill() of mortal.
    }
}