code: def __init__(self, to_pop: Message[Any] | None = None) -> None:
      self.state = None
      self._to_pop = to_pop
  
file_path: bokeh/tests/unit/bokeh/client/test_states.py
imports: from __future__ import annotations
  import pytest
  from typing import Any
  from bokeh.protocol.message import Message
  import bokeh.client.states
label_desc: Use image node_id 1 to create a new MockConnection object  with example: obj = MockConnection(to_pop)