code: def ping(self, timestamp=None):
      try:
          if self._task:
              self._task.send(tasks.PingRequest(self._task.id))
      except Exception:  # noqa
          return False
      return True
  
file_path: clearml/clearml/backend_interface/task/development/worker.py
imports: import attr
  from threading import Thread
  from time import time
  from ....config import deferred_config
  from ....backend_interface.task.development.stop_signal import TaskStopSignal
  from ....backend_api.services import tasks
  from ....utilities.lowlevel.threads import kill_thread
  from ....utilities.process.mp import SafeEvent
label_desc: Use image node_id 2 for calling the DevWorker obj's underlying member method code with example usage: obj.ping(timestamp) and returns: True, False