def test_filter_ips_white_list(self):
        CONF.network_label_regex = '.*'
        CONF.ip_regex = '^(15.|123.)'
        CONF.black_list_regex = '^10.123.123.*'
        ip = self.instance.get_visible_ip_addresses()
        ip = filter_ips(
            ip, CONF.ip_regex, CONF.black_list_regex)
        self.assertEqual(2, len(ip))
        self.assertTrue('123.123.123.123' in ip)
        self.assertTrue('15.123.123.123' in ip)
def deadline_for_course(cls, course_key):
        """
        Retrieve the verification deadline for a particular course.

        Arguments:
            course_key (CourseKey): The identifier for the course.

        Returns:
            datetime or None

        """
        try:
            deadline = cls.objects.get(course_key=course_key)
            return deadline.deadline
        except cls.DoesNotExist:
            return None