code: def asr_tokenizer(test_data_dir):
      tokenizer_path = os.path.join(
          test_data_dir, "asr", "tokenizers", "an4_wpe_128", "vocab.txt"
      )
      tokenizer = tokenizers.AutoTokenizer(
          pretrained_model_name="bert-base-cased",
          vocab_file=tokenizer_path,
      )
      return tokenizer
  
imports: import json
  import multiprocessing
  import os
  from dataclasses import dataclass, field
  from pathlib import Path
  import pytest
  from hydra.utils import instantiate
  from omegaconf import OmegaConf
  from nemo.collections.asr.data.text_to_text import TextToTextDataset, TextToTextItem, TextToTextIterableDataset
  from nemo.collections.common import tokenizers
label_desc: Use image node_id 6 for calling a global function with example usage: asr_tokenizer(test_data_dir) and returns: tokenizer