code: def _untag_sentence(tagged_sentence):
      
      untagged_sentence = TAG_PATT.sub('\\2', tagged_sentence)
      clean_sentence = JUNK_PATT.sub('', untagged_sentence)
      return clean_sentence.strip()
docs: Removes all tags in the sentence, returning the original sentence
      without Medscan annotations.
  
      Parameters
      ----------
      tagged_sentence : str
          The tagged sentence
  
      Returns
      -------
      untagged_sentence : str
          Sentence with tags and annotations stripped out