def corofunc2():
            called[1] += 1
            return event.ReturnValue(insert_events=[evt3], append_events=[evt2])
def expiration_datetime(self):
        """Datetime that the verification will expire. """
        days_good_for = settings.VERIFY_STUDENT["DAYS_GOOD_FOR"]
        return self.created_at + timedelta(days=days_good_for)