def testHourBefore(self):
        # Python's datetime library has a bug, where the hour before
        # a daylight saving transition is one hour out. For example,
        # at the end of US/Eastern daylight saving time, 01:00 EST
        # occurs twice (once at 05:00 UTC and once at 06:00 UTC),
        # whereas the first should actually be 01:00 EDT.
        # Note that this bug is by design - by accepting this ambiguity
        # for one hour one hour per year, an is_dst flag on datetime.time
        # became unnecessary.
        self._test_all(
                timedelta(hours=1) - self.transition_time, self.after
                )
dataset/ETHPy150Open awslabs/lambda-apigateway-twilio-tutorial/pytz/tests/test_tzinfo.py/ReferenceUSEasternDSTEndTestCase.testHourBefore/swapped operands of `-`