code: def _save_label(label_folder: str, filename: str, wav_stem: str):
      label = random.choice(LABELS)
      line = f"[xxx]\t{wav_stem}\t{label}\t[yyy]"
      filepath = os.path.join(label_folder, filename)
  
      with open(filepath, "a") as f:
          f.write(line + "\n")
      return label
  
file_path: audio/test/torchaudio_unittest/datasets/iemocap_test.py
imports: import os
  import random
  from torchaudio.datasets import iemocap
  from torchaudio_unittest.common_utils import get_whitenoise, save_wav, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 2 for calling a global function with example usage: _save_label(label_folder, filename, wav_stem) and returns: label