code: def tree_deflatten_with_delimiter(
      flat_dict: Dict[str, Any], delimiter: str = _DELIMITER
  ) -> Dict[str, Any]:
      """De-flattens a dict to its originally nested structure.
  
      Does the opposite of {combine_nested_keys(k) :v
                            for k, v in tree.flatten_with_path(nested_dicts)}
      Example: {'a:b': 1} -> {'a': {'b': 1}}
      Args:
        flat_dict: the keys of which equals the `path` separated by `delimiter`.
        delimiter: the delimiter that separates the keys of the nested dict.
  
      Returns:
        An un-flattened dict.
      """
      root = collections.defaultdict(dict)
      for delimited_key, v in flat_dict.items():
          keys = _decombine_key(delimited_key, delimiter=delimiter)
          node = root
          for k in keys[:-1]:
              node = node[k]
          node[keys[-1]] = v
      return dict(root)
  
imports: from __future__ import annotations
  import collections
  import dataclasses
  import functools
  import os
  from typing import Any, Dict, Generator, Optional, Sequence, Text, Tuple, Union
  import numpy
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  import tensorflow_datasets.public_api
  from tensorflow_datasets.rl_unplugged import rlu_common
label_desc: Use image node_id 4 for calling a global function with example usage: tree_deflatten_with_delimiter(flat_dict, delimiter) and returns: dict