def test_error(self):
        """
        Test that an observed error gets added to the result
        """
        f = makeFailure()
        self.observer.gotEvent({'message': (),
                                'time': time.time(), 'isError': 1,
                                'system': '-', 'failure': f,
                                'why': None})
        self.assertEqual(self.observer.getErrors(), [f])

        Test that an observed error gets added to the result
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_log.py