code: public List<Word> toSimpleWordList()
      {
          List<Word> wordList = new LinkedList<Word>();
          for (IWord word : this.wordList)
          {
              if (word instanceof CompoundWord)
              {
                  wordList.addAll(((CompoundWord) word).innerList);
              }
              else
              {
                  wordList.add((Word) word);
              }
          }
  
          return wordList;
      }
docs: 转换为简单单词列表
  
  @return