code: def test_incremental_reading_for_missing_files(app):
      # first reading
      updated = app.builder.read()
      assert set(updated) == app.env.found_docs == set(app.env.all_docs)
  
      # second reading
      updated = app.builder.read()
  
      # "index" is listed up to updated because it contains references
      # to nonexisting downloadable or image files
      assert set(updated) == {"index"}
  
label_desc: Use image node_id 2 for calling a global function with example usage: test_incremental_reading_for_missing_files(app) without return types