struct UpdateNicknameMessage: Codable {
 let id: Int
 let nickname: String
 let email: String
}

struct UpdateNickname: Codable {
 var Status: Int
 var Result: String
 var Message: UpdateNicknameMessage

enum CodingKeys: String, CodingKey {
    case Status = "Status"
    case Result = "Result"
    case Message = "Message"
}

init?(from jsonObject: AnyObject) {
    guard let Status1: Int = jsonObject.object(forKey: "Status") as? Int,
        let Result1: String = jsonObject.object(forKey: "Result") as? String,
        let Message1: UpdateNicknameMessage = jsonObject.object(forKey: "Message") as? UpdateNicknameMessage
        else { return nil }

    Status = Status1
    Result = Result1
    Message = Message1
  }
}

["Message": {
    email = "123@123.com";
    id = 56;
    nickname = testNickname;
},
 "Status": 200,
 "Result": success]

let decoder = JSONDecoder()
            do {
                let model = try decoder.decode(UpdateNickname.self, from: data)
                let serverStatus = model.Status

                if serverStatus == 200 {
                     //EVERYTHING IS FINE
                } else {
                     //server not working
                }
            } catch {
               //cant convert JSON into struct
               print(error.localizedDescription)
            }

["Message": <null>,
 "Status": 400,
 "Result": problem]