code: def _bpe_to_words(sentence, delimiter='@@'):
      
      words = []
      word = ''
      delimiter_len = len(delimiter)
      for subwords in sentence:
          if len(subwords) >= delimiter_len and subwords[-delimiter_len:] == delimiter:
              word += subwords[:-delimiter_len]
          else:
              word += subwords
              words.append(word)
              word = ''
      return words
docs: Convert a sequence of bpe words into sentence.