课程教的数据结构都是简单格式的

假如说我想做比较多层级的json，那么schema中应该怎么设置呢？？？例如这里的数据形式，schema中意昂该怎么设呢

{

   "ret":true,

   "data":{"city":"北京",

            "swiperList":[{

                        "id":"001",

                        "url": "https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=4223788855,3310475877&fm=15&gp=0.jpg"

                        },{

                        "id":"002",

                        "url": "https://ss2.bdstatic.com/70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=642059738,468282012&fm=26&gp=0.jpg"

                        },{

                        "id":"003",

                        "url": "https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=1916083798,1139998518&fm=26&gp=0.jpg"

                        }]

            }

}