code: def __iter__(self):
      self.iterator_iter = iter(self.iterator)
      self._start_time = time.time()
      self._init_time = 0.0
      self._iter_time = 0.0
      self._iter_start_step = tracker().global_step
      self._started = False
      self.monitor.start_loop()
      return self
  
file_path: labml/client/labml/internal/monitor/loop.py
imports: import math
  import time
  from typing import Optional, Dict, TYPE_CHECKING, List, Collection
  from labml import logger
  from ..monitor.sections import LoopingSection
  from ..tracker import tracker_singleton
label_desc: Use image node_id 2 for calling the Loop obj's underlying member method code with example usage: obj.__iter__() and returns: self