code: def start(self):
      self._decref_thread = threading.Thread(
          target=self._thread_body, name="DecrefThread"
      )
      self._decref_thread.daemon = True
      self._decref_thread.start()
  
imports: import asyncio
  import atexit
  import concurrent.futures
  import queue
  import threading
  from typing import List
  from weakref import WeakKeyDictionary, ref
  from ...lib.aio import get_isolation
  from ...typing import SessionType, TileableType
  from ..mode import enter_mode
label_desc: Use image node_id 2 for calling the DecrefRunner obj's underlying member method code with example usage: obj.start() without return types