old_contents: import re
  
  
  try:
      import nltk
  
      NLTK_AVAILABLE = True
  except (ImportError, ModuleNotFoundError):
      NLTK_AVAILABLE = False
  
  if NLTK_AVAILABLE:
      try:
          nltk.download("punkt", quiet=True)
      except FileExistsError:  # multiprocessing race condition
          pass
  
  
  def add_newline_to_end_of_each_sentence(x: str) -> str:
      re.sub("<n>", "", x)  # remove pegasus newline char
      assert NLTK_AVAILABLE, "nltk must be installed to separate newlines betwee sentences. (pip install nltk)"
      return "\n".join(nltk.sent_tokenize(x))
  
new_contents: import re
  
  from filelock import FileLock
  
  
  try:
      import nltk
  
      NLTK_AVAILABLE = True
  except (ImportError, ModuleNotFoundError):
      NLTK_AVAILABLE = False
  
  if NLTK_AVAILABLE:
      with FileLock("a_random_string") as lock:
          nltk.download("punkt", quiet=True)
  
  
  def add_newline_to_end_of_each_sentence(x: str) -> str:
      """This was added to get rougeLsum scores matching published rougeL scores for BART and PEGASUS."""
      re.sub("<n>", "", x)  # remove pegasus newline char
      assert NLTK_AVAILABLE, "nltk must be installed to separate newlines between sentences. (pip install nltk)"
      return "\n".join(nltk.sent_tokenize(x))
  
subject: fix nltk pytest race condition with FileLock (#7515)