code: def wait_for_queue(dash_duo):
      # mostly for cases where no callbacks should fire:
      # just wait until we have the button and the queue is empty
      dash_duo.wait_for_text_to_equal("#btn", "click")
      wait.until(lambda: not dash_duo.redux_state_is_loading, 3)
  
file_path: dash/tests/integration/callbacks/test_missing_inputs.py
imports: import json
  from dash.testing import wait
  from dash import Dash, Input, Output, State, ALL, MATCH, html
label_desc: Use image node_id 1 for calling a global function with example usage: wait_for_queue(dash_duo) without return types