code: def generate_vocab_file():
      """Generate Vocab file for test."""
      tmpdir = Path(tempfile.mkdtemp())
      vocab_file = str(tmpdir.joinpath("vocab.txt"))
      dummy_vocabs = ["</s>", "<unk>", "你好", "北京"]
      save_a_vocab_file(vocab_file, dummy_vocabs)
      return vocab_file
  
file_path: delta/delta/data/utils/test_utils.py
imports: import json
  import tempfile
  from pathlib import Path
  import kaldiio
  import numpy
  from delta.data.utils.common_utils import JsonNumpyEncoder
label_desc: Use image node_id 2 for calling a global function with example usage: generate_vocab_file() and returns: vocab_file