code: def test_basic(self) -> None:
      d = Document()
      dm = bdm.DocumentModuleManager(d)
      assert len(dm) == 0
  
      # module manager should only hold a weak ref
      assert len(gc.get_referrers(d)) == 0
  
file_path: bokeh/tests/unit/bokeh/document/test_modules.py
imports: from __future__ import annotations
  import pytest
  import gc
  import logging
  import sys
  from bokeh.document import Document
  from bokeh.util.logconfig import basicConfig
  import bokeh.document.modules
label_desc: Use image node_id 1 for calling the TestDocumentModuleManager obj's underlying member method code with example usage: obj.test_basic() without return types