code: def start(self, container: "MetadataContainer"):
      self._thread = self.ReportingThread(self._period, container)
      self._thread.start()
      self._started = True
  
file_path: neptune-client/src/neptune/internal/utils/ping_background_job.py
imports: import logging
  from typing import TYPE_CHECKING, Optional
  from neptune.internal.background_job import BackgroundJob
  from neptune.internal.threading.daemon import Daemon
label_desc: Use image node_id 2 for calling the PingBackgroundJob obj's underlying member method code with example usage: obj.start(container) without return types