code: public String getAmbiguityClass(final String word) {
      final TreeMultimap<Integer, String> mfTagMap = getOrderedMap(word);
      String ambiguityClass = null;
      if (!mfTagMap.isEmpty()) {
        StringJoiner sb = new StringJoiner("-");
        for (Map.Entry<Integer, String> entry : mfTagMap.entries()) {
          sb.add(entry.getValue());
        }
        ambiguityClass = sb.toString();
        //System.err.println(ambiguityClass);
      } else {
        ambiguityClass = "O";
      }
      return ambiguityClass;
    }
docs: TODO serialization of this resource pending