private void buildAttributes(GenericRecord record, String field, LuceneWorksBuilder hydrator) {
   @SuppressWarnings("unchecked")
   List<List<?>> tokens = (List<List<?>>) record.get(field);
   for (List<?> token : tokens) {
     for (Object attribute : token) {
       buildAttribute(attribute, hydrator);
     }
     hydrator.addToken();
   }
 }