code: public List<IWord> findWordsByLabel(String label)
      {
          List<IWord> wordList = new LinkedList<IWord>();
          for (IWord word : this)
          {
              if (label.equals(word.getLabel()))
              {
                  wordList.add(word);
              }
          }
          return wordList;
      }
docs: 找出所有词性为label的单词（不检查复合词内部的简单词）
  
  @param label
  @return