code: def join(self, timeout: Optional[float] = None) -> None:
      self._exit_event.set()
      super().join(timeout)
  
file_path: pytorch-lightning/src/lightning/app/utilities/scheduler.py
imports: import threading
  from datetime import datetime
  from typing import Optional
  from croniter import croniter
  from deepdiff import Delta
  from lightning.app.utilities.proxies import ComponentDelta
label_desc: Use image node_id 4 for calling the SchedulerThread obj's underlying member method code with example usage: obj.join(timeout) without return types