code: def test_visit_immediate_value_references() -> None:
      r1 = LayoutDOM()
      r2 = LayoutDOM()
      row = Row(children=[LayoutDOM()])
      obj = Row(children=[r1, r2, row])
      vals = set()
      assert (
          bmu.visit_immediate_value_references(
              obj, lambda x: vals.add(x)
          )
          is None
      )
      assert vals == {r1, r2, row}
  
imports: from __future__ import annotations
  import pytest
  from dataclasses import dataclass
  from bokeh.core.has_props import Local
  from bokeh.core.properties import Dict, Instance, Int, List, Nullable, Object, Tuple
  from bokeh.document import Document
  from bokeh.model import Model
  from bokeh.models import LayoutDOM, Row
  import bokeh.model.util
label_desc: Use image node_id 3 for calling a global function with example usage: test_visit_immediate_value_references() without return types