def METHOD_NAME(store_app, dash_dcc):
    app = Dash(__name__)
    app.layout = html.Div(
        [
            dcc.Store(id="initial-storage", storage_type="session"),
            html.Button("set-init-storage", id="set-init-storage"),
            html.Div(id="init-output"),
        ]
    )
    @app.callback(
        Output("initial-storage", "data"),
        [Input("set-init-storage", "n_clicks")],
    )
    def on_init(n_clicks):
        if n_clicks is None:
            raise PreventUpdate
        return "initialized"
    @app.callback(
        Output("init-output", "children"),
        [Input("initial-storage", "modified_timestamp")],
        [State("initial-storage", "data")],
    )
    def init_output(ts, data):
        return json.dumps({"data": data, "ts": ts})
    dash_dcc.start_server(app)
    dash_dcc.find_element("#set-init-storage").click()
    # the python ts ends at seconds while javascript one ends at ms
    ts = float(time.time() * 1000)
    wait.until(
        lambda: "initialized" in dash_dcc.find_element("#init-output").text, timeout=3
    )
    output_data = json.loads(dash_dcc.find_element("#init-output").text)
    assert (
        output_data.get("data") == "initialized"
    ), "the data should be the text set in on_init"
    assert ts == approx(
        output_data.get("ts"), abs=40
    ), "the modified_timestamp should be updated right after the click action"
    assert dash_dcc.get_logs() == []