def test_sslWithDefaults(self):
        """
        An SSL string endpoint description with minimal arguments returns
        a properly initialized L{SSL4ServerEndpoint} instance.
        """
        reactor = object()
        server = endpoints.serverFromString(
            reactor, "ssl:4321:privateKey=%s" % (escapedPEMPathName,))
        self.assertIsInstance(server, endpoints.SSL4ServerEndpoint)
        self.assertIs(server._reactor, reactor)
        self.assertEqual(server._port, 4321)
        self.assertEqual(server._backlog, 50)
        self.assertEqual(server._interface, "")
        self.assertEqual(server._sslContextFactory.method, SSLv23_METHOD)
        self.assertTrue(
            server._sslContextFactory._options & OP_NO_SSLv3,
        )
        ctx = server._sslContextFactory.getContext()
        self.assertIsInstance(ctx, ContextType)

        An SSL string endpoint description with minimal arguments returns
        a properly initialized L{SSL4ServerEndpoint} instance.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_endpoints.py