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/tests/templates/fetching_ddp_dynbatch_finetuning/mini_librispeech_prepare.py
imports: import os
  import json
  import shutil
  import logging
  from speechbrain.utils.data_utils import get_all_files, download_file
  from speechbrain.dataio.dataio import read_audio
label_desc: Use image node_id 4 for calling a global function with example usage: skip() and returns: True, False