def test_service(self):
        """
        L{strports.service} returns a L{StreamServerEndpointService}
        constructed with an endpoint produced from
        L{endpoint.serverFromString}, using the same syntax.
        """
        reactor = object() # the cake is a lie
        aFactory = Factory()
        aGoodPort = 1337
        svc = strports.service(
            'tcp:' + str(aGoodPort), aFactory, reactor=reactor)
        self.assertIsInstance(svc, internet.StreamServerEndpointService)

        # See twisted.application.test.test_internet.EndpointServiceTests.
        # test_synchronousRaiseRaisesSynchronously
        self.assertTrue(svc._raiseSynchronously)
        self.assertIsInstance(svc.endpoint, TCP4ServerEndpoint)
        # Maybe we should implement equality for endpoints.
        self.assertEqual(svc.endpoint._port, aGoodPort)
        self.assertIs(svc.factory, aFactory)
        self.assertIs(svc.endpoint._reactor, reactor)

        L{strports.service} returns a L{StreamServerEndpointService}
        constructed with an endpoint produced from
        L{endpoint.serverFromString}, using the same syntax.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_strports.py