def test_unknownArgument(self):
        """
        Verify that unknown arguments are ignored, and not passed to a Python
        function which can't accept them.
        """
        c, s, p = connectedServerAndClient(
            ServerClass=SimpleSymmetricCommandProtocol,
            ClientClass=SimpleSymmetricCommandProtocol)
        L = []
        HELLO = b'world'
        # c.sendHello(HELLO).addCallback(L.append)
        c.callRemote(FutureHello,
                     hello=HELLO,
                     bonus=b"I'm not in the book!").addCallback(
            L.append)
        p.flush()
        self.assertEqual(L[0]['hello'], HELLO)

        Verify that unknown arguments are ignored, and not passed to a Python
        function which can't accept them.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_amp.py