code: def _tree_dict() -> TreeDict:
      """Nested dict."""
      return collections.defaultdict(_tree_dict)
  
file_path: datasets/tensorflow_datasets/scripts/cleanup/delete_old_versions.py
imports: import collections
  import concurrent.futures
  import dataclasses
  import os
  import pathlib
  from typing import Dict, Iterable, List, Tuple
  from absl import app
  from absl import flags
  import tensorflow_datasets
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  import termcolor
label_desc: Use image node_id 1 for calling a global function with example usage: _tree_dict() and returns: collections