docs: public static void append(String key, String[] words) {
  
          SmartForest<List<String>> synonyms = get(key);
  
          Set<String> set = new HashSet<>();
  
          for (String word : words) {
              if (StringUtil.isBlank(word)) {
                  continue;
              }
              set.add(word);
          }
  
          if (set.size() <= 1) {
              LOG.warn(Arrays.toString(words) + " not have any change because it less than 2 word");
              return;
          }
  
          set.addAll(findAllWords(key, words));
  
          List<String> list = new ArrayList<>(set);
  
          for (String word : list) {
              synonyms.addBranch(word, list);
          }
      }