code: def skip(save_train, save_dev, save_test):
      """
      Detects if the MultiWOZ 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.
      """
  
      # Checking folders and save options
      skip = False
  
      if (
          os.path.isfile(save_train)
          and os.path.isfile(save_dev)
          and os.path.isfile(save_test)
      ):
          skip = True
  
      return skip
  
imports: from itertools import product
  from statistics import mean
  from typing import Any, Dict, List, Optional, Set, Tuple
  import json
  import logging
  import os
  import re
  import shutil
  from tqdm import tqdm
  from speechbrain.utils.data_utils import download_file
label_desc: Use image node_id 4 for calling a global function with example usage: skip(save_train, save_dev, save_test) and returns: skip