'Verify that course mode upgrade deadlines can be removed through the API.'

def test_remove_upgrade_deadline(self):

    upgrade_deadline = (datetime.now(pytz.utc) + timedelta(days=1))
    (response, __) = self._get_update_response_and_expected_data(upgrade_deadline, None)
    self.assertEqual(response.status_code, 200)
    verified_mode = CourseMode.verified_mode_for_course(self.course.id)
    self.assertIsNotNone(verified_mode)
    self.assertEqual(verified_mode.expiration_datetime.date(), upgrade_deadline.date())
    (response, __) = self._get_update_response_and_expected_data(None, None)
    self.assertEqual(response.status_code, 200)
    updated_verified_mode = CourseMode.verified_mode_for_course(self.course.id)
    self.assertIsNotNone(updated_verified_mode)
    self.assertIsNone(updated_verified_mode.expiration_datetime)
