code: def skip(*filenames):
      """
      Detects if the data preparation has been already done.
      If the preparation has been done, we can skip it.
      Returns
      -------
      bool
          if True, the preparation phase can be skipped.
          if False, it must be done.
      """
      for filename in filenames:
          if not os.path.isfile(filename):
              return False
      return True
  
file_path: speechbrain/recipes/LibriTTS/TTS/mstacotron2/libritts_prepare.py
imports: from speechbrain.utils.data_utils import get_all_files, download_file
  import json
  import os
  import shutil
  import random
  import logging
  import torchaudio
  import torch
  from tqdm import tqdm
  from speechbrain.inference.txt import GraphemeToPhoneme
  from speechbrain.utils.text_to_sequence import _g2p_keep_punctuations
label_desc: Use image node_id 4 for calling a global function with example usage: skip() and returns: True, False