docs: public static void insertOrCreate(String key, String keyword, String nature, int freq) {
  		Forest dic = get(key);
  		if(dic==null){
  			dic = new Forest() ;
  			put(key,key,dic);
  		}
  		String[] paramers = new String[2];
  		paramers[0] = nature;
  		paramers[1] = String.valueOf(freq);
  		Value value = new Value(keyword, paramers);
  		Library.insertWord(dic, value);
  	}