code: def start(self):
      self.starting_loop = ensure_event_loop()
      loop = asyncio.get_event_loop()
      loop.run_until_complete(self._inner())
      loop.close()
  
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 1 for calling the SyncTornadoApp obj's underlying member method code with example usage: obj.start() without return types