def test_reprWithClassicProtocol(self):
        """
        The two string representations of the L{IListeningPort} returned by
        L{IReactorUNIXDatagram.listenUNIXDatagram} contains the name of the
        classic protocol class being used and the filename on which the port is
        listening or indicates that the port is not listening.
        """
        class ClassicProtocol:
            def makeConnection(self, transport):
                pass

            def doStop(self):
                pass

        # Sanity check
        self.assertIsInstance(ClassicProtocol, types.ClassType)

        return self._reprTest(
            ClassicProtocol(), "twisted.test.test_unix.ClassicProtocol")

        The two string representations of the L{IListeningPort} returned by
        L{IReactorUNIXDatagram.listenUNIXDatagram} contains the name of the
        classic protocol class being used and the filename on which the port is
        listening or indicates that the port is not listening.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_unix.py