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 test_between_or_equal_to():
    """Greater than or equal to y and less than or equal to z."""
    p = are.between_or_equal_to(3, 3)
    ps = [p(x) for x in range(1, 6)]
    assert ps == [False, False, True, False, False]