code: def tone_marks(text):
      
      return PreProcessorRegex(
          search_args=symbols.TONE_MARKS,
          search_func=lambda x: u"(?<={})".format(x),
          repl=' ').run(text)
docs: Add a space after tone-modifying punctuation.
  
      Because the `tone_marks` tokenizer case will split after a tone-modidfying
      punctuation mark, make sure there's whitespace after.