def test_tcpPortPositionalArg(self):
        """
        When passed a TCP strports description specifying port as a positional
        argument, L{endpoints.clientFromString} returns a L{TCP4ClientEndpoint}
        instance initialized with the values from the string.
        """
        reactor = object()
        client = endpoints.clientFromString(
            reactor,
            "tcp:host=example.com:1234:timeout=7:bindAddress=10.0.0.2")
        self.assertEqual(client._host, "example.com")
        self.assertEqual(client._port, 1234)

        When passed a TCP strports description specifying port as a positional
        argument, L{endpoints.clientFromString} returns a L{TCP4ClientEndpoint}
        instance initialized with the values from the string.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_endpoints.py