def test_logout(self):
        """
        The realm's logout callback is invoked after the resource is rendered.
        """
        request = self._logoutTest()
        request.finish()
        self.assertEqual(self.realm.loggedOut, 1)

        The realm's logout callback is invoked after the resource is rendered.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_httpauth.py