code: def build_reverse_dictionary(word_to_id):
      
      reverse_dictionary = dict(zip(word_to_id.values(), word_to_id.keys()))
      return reverse_dictionary
docs: Given a dictionary that maps word to integer id.
      Returns a reverse dictionary that maps a id to word.
  
      Parameters
      ----------
      word_to_id : dictionary
          that maps word to ID.
  
      Returns
      --------
      dictionary
          A dictionary that maps IDs to words.