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 insert(root, key):
    left, right = split(root, key)
    return merge(merge(left, Treap(key)), right)