def test_remove(self):
        prio_set_list = event._PrioritizedSetList()
        obj = (1,)

        prio_set_list.add(1, obj)
        assert prio_set_list
        prio_set_list.remove(obj)
        assert not prio_set_list

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.remove(obj)
        excinfo.match(r"can not be found")
def kth(root, k):
    if k < size(root.left):
        return kth(root.left, k)
    elif k > size(root.left):
        return kth(root.right, k - size(root.left) - 1)
    return root.key