def test_repr(self):
        """
        L{runner.ErrorHolder.__repr__} returns a string describing the error it
        holds.
        """
        expected = (
            "<ErrorHolder description='description' "
            "error={}>".format(repr(self.holder.error[1]))
        )

        self.assertEqual(repr(self.holder), expected)

        L{runner.ErrorHolder.__repr__} returns a string describing the error it
        holds.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_runner.py