code: public List<String> lemmatize(String[] tokens, String[] posTags) {
      String[] annotatedLemmas = lemmatizer.lemmatize(tokens, posTags);
      String[] decodedLemmas = lemmatizer.decodeLemmas(tokens, annotatedLemmas);
      final List<String> lemmas = new ArrayList<String>(Arrays.asList(decodedLemmas));
      return lemmas;
    }
docs: Produce lemmas from a tokenized sentence and its postags.
  @param tokens the tokens
  @param posTags the pos tags
  @return the lemmas