def test_original_failure(self):
        try:
            1/0
        except:
            f = Failure()
        dr = EventualResult(fail(f), None)
        self.assertIdentical(dr.original_failure(), f)
original_failure() returns the underlying Failure of the Deferred
dataset/ETHPy150Open itamarst/crochet/crochet/tests/test_api.py/EventualResultTests.test_original_failure