code: def __init__(self):
      self.timings = []
      self.begin = None
  
imports: import errno
  import os
  import shutil
  import tempfile
  import time
  import warnings
  import chainer
  from chainer.training import extension
label_desc: Use image node_id 1 to create a new _CheckpointStats object from inherited base classes: object with example: obj = _CheckpointStats()