code: public static void put(Object obj, String path, Object val) {
          Object mapList = Mapl.toMaplist(val);
          MaplRebuild rebuild = new MaplRebuild(obj);
          rebuild.put(path, mapList);
      }
docs: 添加新的结点
  
  @param obj
  原始的MapList
  @param path
  路径
  @param val
  值