code: def test_cli_override():
      app = DummyApp()
      td = mkdtemp()
      fname = pjoin(td, "config.py")
      with open(fname, "w", encoding="utf-8") as f:
          f.write(_dummy_config)
      app.initialize(["--config", fname, "--DummyApp.n=20"])
      shutil.rmtree(td)
      assert app.n == 20
  
imports: from __future__ import annotations
  import asyncio
  import os
  import shutil
  from tempfile import mkdtemp
  from unittest.mock import patch
  import pytest
  from traitlets import Integer
  from jupyter_core.application import JupyterApp, JupyterAsyncApp, NoStart
  from jupyter_core.utils import ensure_event_loop
label_desc: Use image node_id 4 for calling a global function with example usage: test_cli_override() without return types