def test_startServiceStarted(self):
        """
        L{StreamServerEndpointService.startService} sets the C{running} flag,
        but nothing else, if the service has already been started.
        """
        self.test_privilegedStartService()
        self.svc.startService()
        self.assertEqual(self.fakeServer.listenAttempts, 1)
        self.assertEqual(self.svc.running, True)

        L{StreamServerEndpointService.startService} sets the C{running} flag,
        but nothing else, if the service has already been started.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/application/test/test_internet.py