如何解析json文件中的嵌套字典？

Question

"geometry": {
    "location": {
        "lat": -33.8710748,
        "lng": 151.1989921
    },
    "viewport": {
        "northeast": {
            "lat": -33.86946102010727,
            "lng": 151.2000783298927
        },
        "southwest": {
            "lat": -33.87216067989272,
            "lng": 151.1973786701072
        }
    }
},
"icon": "https://maps.gstatic.com/mapfiles/place_api/icons/restaurant-71.png",
"id": "cbdb9bdfa9d40e704c628f261adeef9875a5ccd7",
"name": "Harbour Bar & Kitchen",
"opening_hours": {
    "open_now": true
},

这是来自Google地图网址的json文件。我想将其解码为swift对象。我尝试了不同的方法，但没有一个起作用。下面的代码可以成功获取“名称”，但不能获取lat和lng。是否可以使用nestedContainer来获取lat和lng的值？

class VolumeData:NSObject, Decodable
{
  var gyms:[GymData] ? private enum CodingKeys : String, CodingKey
  { case gyms = "results" }
}
class GymData:NSObject, Decodable
{
  var lat:String ? var lng : String ? var name : String private enum
    RootKeys:String, CodingKey
  {
    case name = "name" case geometry =
      "geometry" enum NestedCodingKeys:String,
    CodingKey
    { case lat = "lat" case lng = "lng" }
  }
  required init (from decoder:Decoder) throws
  {
    // Get the root container first
let rootContainer = try decoder.container (keyedBy:
  RootKeys.self) let locContainer = try rootContainer.nestedContainer (keyedBy:RootKeys.NestedCodingKeys.self,
  forKey:        .geometry)
      //            let locContainer = try geoContainer.nestedContainer(keyedBy:
      //                GeoKeys.self, forKey: .location)
      // Get the gym info
  self.name = try rootContainer.decode (String.self, forKey:.name)
      self.lat = try ? locContainer.decode (String.self, forKey :.lat)
      self.lng = try ? locContainer.decode (String.self, forKey :.lng)
  }
}