code: def __init__(self, doc: Document) -> None:
      self._document = doc
      self.status = None
      self.counter = 0
  
file_path: bokeh/tests/unit/bokeh/application/handlers/test_document_lifecycle.py
imports: from __future__ import annotations
  import pytest
  import logging
  from bokeh.document import Document
  import bokeh.application.handlers.document_lifecycle
label_desc: Use image node_id 1 to create a new MockSessionContext object  with example: obj = MockSessionContext(doc)