code: def __lt__(self, other):
      return self.t_expire < other.t_expire
  
file_path: river/river/stream/qa.py
imports: from __future__ import annotations
  import bisect
  import collections
  import datetime
  import typing
  from copy import deepcopy
  from river import base
label_desc: Use image node_id 1 for calling the Memento obj's underlying member method code with example usage: obj.__lt__(other) and returns: unknown