docs: List<List<IWord>> sentenceTokenize(List<Sentence> sentence) throws IOException
      {
          List<List<IWord>> senWords = new ArrayList<List<IWord>>();
          for ( Sentence sen : sentence ) {
              List<IWord> words = new ArrayList<IWord>();
              wordSeg.reset(new StringReader(sen.getValue()));
              IWord word = null;
              while ( (word = wordSeg.next()) != null ) {
                  words.add(word);
              }
              
              senWords.add(words);
          }
          
          return senWords;
      }