def test_tcpPositionalArgs(self):
        """
        When passed a TCP strports description using positional arguments,
        L{endpoints.clientFromString} returns a L{TCP4ClientEndpoint} instance
        initialized with the values from the string.
        """
        reactor = object()
        client = endpoints.clientFromString(
            reactor,
            "tcp:example.com:1234:timeout=7:bindAddress=10.0.0.2")
        self.assertIsInstance(client, endpoints.TCP4ClientEndpoint)
        self.assertIs(client._reactor, reactor)
        self.assertEqual(client._host, "example.com")
        self.assertEqual(client._port, 1234)
        self.assertEqual(client._timeout, 7)
        self.assertEqual(client._bindAddress, ("10.0.0.2", 0))

        When passed a TCP strports description using positional arguments,
        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