    def test_basic_auth_invalid_credentials(self):
        with self.assertRaises(InvalidStatusCode) as raised:
            self.start_client(user_info=("hello", "ihateyou"))
        self.assertEqual(raised.exception.status_code, 401)
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.