def test_make_helpful_exception(self):
        class TriggerException(HashedFilesMixin):
            def exists(self, path):
                return False
        exception = None
        try:
            TriggerException().hashed_name('/missing/file.png')
        except __HOLE__ as e:
            exception = e
        helpful_exception = HelpfulExceptionMixin().make_helpful_exception(
                                exception,
                                'styles/app.css'
                            )
        self.assertIsInstance(helpful_exception, MissingFileError)
dataset/ETHPy150Open evansd/whitenoise/tests/test_storage.py/DjangoWhiteNoiseStorageTest.test_make_helpful_exception