def test_bool(self):
        prio_set_list = event._PrioritizedSetList()

        assert bool(prio_set_list) is False

        prio_set_list.add(0, None)
        assert bool(prio_set_list) is True
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