def tearDown(self):
        """
        Disconnect the server protocol so it can clean up anything it might
        need to clean up.
        """
        self.pop3Server.connectionLost(failure.Failure(
                                       Exception("Test harness disconnect")))

        Disconnect the server protocol so it can clean up anything it might
        need to clean up.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_pop3.py