code: def __str__(self):
      return "LabTrainingLoop"
  
imports: import signal
  import typing
  from typing import Optional, Tuple, Any, Collection
  from labml import tracker, logger, experiment, monit
  from labml.configs import BaseConfigs, meta_config, option
  from labml.internal.monitor import Loop
  from labml.logger import Text
label_desc: Use image node_id 7 for calling the TrainingLoop obj's underlying member method code with example usage: obj.__str__() and returns: str