code: def checkpoint(self, stage, msg=""):
          
          # Canonical usage model for Pipeline checkpointing through
          # implementations of this class is by automatically creating a
          # checkpoint when a conceptual unit or group of operations of a
          # pipeline completes, so fix the 'finished' parameter to the manager's
          # timestamp method to be True.
          return self.manager.timestamp(
                  message=msg, checkpoint=stage.checkpoint_name, finished=True)
docs: Touch checkpoint file for given stage and provide timestamp message.
  
          :param pypiper.Stage stage: Stage for which to mark checkpoint
          :param str msg: Message to embed in timestamp.
          :return bool: Whether a checkpoint file was written.