class_docstr: An utterance. 
class_docstr_tok: ["An","utterance","."]
code: def __init__(
      self, default_factory=None
  ):  # pylint: disable=unused-argument
      super().__init__(_return_none)
  
file_path: delta/delta/utils/kaldi/kaldi_dir.py
imports: import os
  from collections import defaultdict
  from absl import logging
label_desc: Use image node_id 1 to create a new Utt object from inherited base classes: defaultdict with example: obj = Utt(default_factory)