code: def test_dync001_dynamic_callback(dash_duo):
      app = Dash()
  
      app.layout = html.Div(
          [
              html.Div(id="output"),
              html.Button("create", id="create"),
              html.Div("initial", id="output-2"),
              html.Button("dynamic", id="dynamic"),
          ]
      )
  
      @app.callback(
          Output("output", "children"),
          Input("create", "n_clicks"),
          _allow_dynamic_callbacks=True,
          prevent_initial_call=True,
      )
      def on_click(n_clicks):
          @app.callback(
              Output("output-2", "children"),
              Input("dynamic", "n_clicks"),
              prevent_initial_call=True,
          )
          def on_click2(n_clicks2):
              return f"Dynamic clicks {n_clicks2}"
  
          return f"creator {n_clicks}"
  
      dash_duo.start_server(app)
  
      dash_duo.wait_for_element("#dynamic").click()
      dash_duo.wait_for_element("#create").click()
      dash_duo.wait_for_text_to_equal("#output", "creator 1")
      dash_duo.wait_for_text_to_equal("#output-2", "initial")
  
      dash_duo.wait_for_element("#dynamic").click()
      dash_duo.wait_for_text_to_equal("#output-2", "Dynamic clicks 2")
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_dync001_dynamic_callback(dash_duo) and returns: str, n_clicks, str, n_clicks2