code: def get_nested_dict_value(dictionary: dict, key: str):
      """
      the key should be a string of nested keys separated by `.`, e.g. `key1.key2.key3`,
      then the returned value will be `dictionary[key1][key2][key3]`
      """
      nested_keys = key.split(".")
      result = dictionary
      for k in nested_keys:
          if k not in result:
              raise KeyError(
                  f"Key `{key}` not found in [{result.keys()}], target is {nested_keys}, input is {dictionary}"
              )
          result = result[k]
      return result
  
imports: from typing import Callable, Dict, List, Optional, Tuple, Union
  import datasets
  import torch
  from datasets import concatenate_datasets
  from datasets.distributed import split_dataset_by_node
  from omegaconf import DictConfig, ListConfig, open_dict
  from nemo.collections.asr.data.audio_to_text import _speech_collate_fn
  from nemo.collections.asr.parts.preprocessing.perturb import AudioAugmentor
  from nemo.collections.asr.parts.preprocessing.segment import AudioSegment
  from nemo.collections.asr.parts.utils.audio_utils import ChannelSelectorType
  from nemo.collections.common import tokenizers
  from nemo.collections.common.parts.preprocessing import parsers
  from nemo.core.classes import Dataset, IterableDataset
  from nemo.core.neural_types import AudioSignal, LabelsType, LengthsType, NeuralType
  from nemo.utils import logging
label_desc: Use image node_id 1 for calling a global function with example usage: get_nested_dict_value(dictionary, key) and returns: result