code: def start(self):
      if self._threaded:
          self._thread = thread = threading.Thread(target=self._run)
          thread.daemon = True
          thread.start()
          self._thread_ident = thread.ident
  
file_path: mars/mars/lib/aio/isolation.py
imports: import asyncio
  import atexit
  import threading
  from typing import Dict, Optional
label_desc: Use image node_id 3 for calling the Isolation obj's underlying member method code with example usage: obj.start() without return types