def test_extrasRequiresTlsDeps(self):
        """
        L{_EXTRAS_REQUIRE}'s C{tls} extra contains setuptools requirements for
        the packages required to make Twisted's transport layer security fully
        work for both clients and servers.
        """
        deps = _EXTRAS_REQUIRE['tls']
        self.assertIn('pyopenssl >= 16.0.0', deps)
        self.assertIn('service_identity >= 18.1.0', deps)
        self.assertIn('idna >= 0.6, != 2.3', deps)

        L{_EXTRAS_REQUIRE}'s C{tls} extra contains setuptools requirements for
        the packages required to make Twisted's transport layer security fully
        work for both clients and servers.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_setup.py