code: def start(self, container: "MetadataContainer") -> None:
      self._thread = SignalsProcessor(
          period=self._period,
          container=container,
          queue=self._queue,
          async_lag_threshold=self._async_lag_threshold,
          async_no_progress_threshold=self._async_no_progress_threshold,
          async_lag_callback=self._async_lag_callback,
          async_no_progress_callback=self._async_no_progress_callback,
      )
      self._thread.start()
      self._started = True
  
file_path: neptune-client/src/neptune/internal/signals_processing/background_job.py
imports: from queue import Queue
  from typing import TYPE_CHECKING, Callable, Optional
  from neptune.internal.background_job import BackgroundJob
  from neptune.internal.signals_processing.signals_processor import SignalsProcessor
label_desc: Use image node_id 2 for calling the CallbacksMonitor obj's underlying member method code with example usage: obj.start(container) without return types