def test_requiresNoAnswer(self):
        """
        Verify that a command that requires no answer is run.
        """
        c, s, p = connectedServerAndClient(
            ServerClass=SimpleSymmetricCommandProtocol,
            ClientClass=SimpleSymmetricCommandProtocol)
        HELLO = b'world'
        c.callRemote(NoAnswerHello, hello=HELLO)
        p.flush()
        self.assertTrue(s.greeted)

        Verify that a command that requires no answer is run.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_amp.py