@Override
 public Map<String, String> queryByIndexKey(String indexKey, Integer size) {
   if (size == null) {
     size = MAX_SIZE;
   }
   List<Tags> list = tagsCategoryCollectionDao.queryByIndexKey(indexKey, size);
   Map<String, String> map = new HashMap<String, String>();
   for (Tags t : list) {
     map.put(t.getTags(), t.getTagsEncode());
   }
   return map;
 }