def test_add_already_added(self):
        prio_set_list = event._PrioritizedSetList()
        obj = object()
        prio_set_list.add(0, obj)

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.add(0, obj)
        excinfo.match(r"has already been added")

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.add(1, obj)
        excinfo.match(r"has already been added")
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]