code: def test_with_multple_callbacks(self) -> None:
      cb1 = CustomJS(code="foo")
      cb2 = CustomJS(code="bar")
      m = SomeModel()
      m.js_on_event("document_ready", cb1, cb2)
      assert m.js_event_callbacks == {"document_ready": [cb1, cb2]}
  
imports: from __future__ import annotations
  import pytest
  from bokeh.core.has_props import is_abstract
  from bokeh.core.properties import Int, List, String
  from bokeh.core.types import ID
  from bokeh.models import *
  from bokeh.models import CustomJS
  from bokeh.plotting import *
  from bokeh.document import document
  from bokeh.model import Model
label_desc: Use image node_id 2 for calling the Test_js_on_event obj's underlying member method code with example usage: obj.test_with_multple_callbacks() without return types