content: from dash import Dash, Input, Output, dcc, html, page_container, register_page
  
  from tests.background_callback.utils import get_background_callback_manager
  
  background_callback_manager = get_background_callback_manager()
  handle = background_callback_manager.handle
  
  
  app = Dash(
      __name__,
      use_pages=True,
      pages_folder="",
      background_callback_manager=background_callback_manager,
  )
  
  app.layout = html.Div(
      [
          dcc.Link("page1", "/"),
          dcc.Link("page2", "/2"),
          html.Button("Cancel", id="shared_cancel"),
          page_container,
      ]
  )
  app.test_lock = lock = background_callback_manager.test_lock
  
  register_page(
      "one",
      "/",
      layout=html.Div(
          [
              html.Button("start", id="start1"),
              html.Button("cancel1", id="cancel1"),
              html.Div("idle", id="progress1"),
              html.Div("initial", id="output1"),
              html.Div("no-cancel-btn", id="no-cancel-btn"),
              html.Div("no-cancel", id="no-cancel-output"),
          ]
      ),
  )
  register_page(
      "two",
      "/2",
      layout=html.Div(
          [
              html.Button("start2", id="start2"),
              html.Button("cancel2", id="cancel2"),
              html.Div("idle", id="progress2"),
              html.Div("initial", id="output2"),
          ]
      ),
  )
  
  
  @app.callback(
      Output("no-cancel-output", "children"),
      Input("no-cancel-btn", "n_clicks"),
      background=True,
      prevent_initial_call=True,
  )
  def on_click_no_cancel(_):
      return "Not Canceled"
  
  
  @app.callback(
      Output("output1", "children"),
      Input("start1", "n_clicks"),
      running=[
          (Output("progress1", "children"), "running", "idle"),
      ],
      cancel=[
          Input("cancel1", "n_clicks"),
          Input("shared_cancel", "n_clicks"),
      ],
      background=True,
      prevent_initial_call=True,
      interval=300,
  )
  def on_click1(n_clicks):
      with lock:
          pass
      return f"Click {n_clicks}"
  
  
  @app.callback(
      Output("output2", "children"),
      Input("start2", "n_clicks"),
      running=[
          (Output("progress2", "children"), "running", "idle"),
      ],
      cancel=[
          Input("cancel2", "n_clicks"),
          Input("shared_cancel", "n_clicks"),
      ],
      background=True,
      prevent_initial_call=True,
      interval=300,
  )
  def on_click1(n_clicks):
      with lock:
          pass
      return f"Click {n_clicks}"
  
  
  if __name__ == "__main__":
      app.run(debug=True)
  