code: def test_safe_to_fork(self) -> None:
      doc = Document()
      handler = bahc.CodeHandler(
          source="# This script does nothing",
          filename="path/to/test_filename",
      )
      assert handler.safe_to_fork
      handler.modify_document(doc)
      if handler.failed:
          raise RuntimeError(handler.error)
      assert not handler.safe_to_fork
  
file_path: bokeh/tests/unit/bokeh/application/handlers/test_code.py
imports: from __future__ import annotations
  import pytest
  from bokeh.document import Document
  import bokeh.application.handlers.code
label_desc: Use image node_id 7 for calling the TestCodeHandler obj's underlying member method code with example usage: obj.test_safe_to_fork() without return types