ios - ObjectMapper を使用してこの JSON をマップする方法は?

Question

Web サービスからの応答でこの JSON を取得しています。ファイルの構造は理解できました。

 {"response":200,"message":"fetch successfully","data":[
{"id":1,"question":"Are you currently exercising regularly?","choices":{"too_lazy":"Too lazy","times_1_3_week":"1-3 times a week","i_love_it":"I just love it!"},"answer_select":"single"},
{"id":2,"question":"Are you active member of Gym?","choices":{"yes":"Yes","no":"No"},"answer_select":"single"}]
 }

そして、これは私がこれまでに持っているものです

import Foundation
import UIKit
import ObjectMapper

class YASUserQuestion: Mappable {

var question: String
var id: Int
var choices: [YASExercisingQuestionChoices]
required init?(_ map: Map) {
    question = ""
    id = 0
    choices = []

}

func mapping(map: Map) {

    question        <- map["question"]
    id              <- map["id"]
    choices         <- map["choices"]
}
}

class YASExercisingQuestionChoices: Mappable {

var tooLazy: String
var times_1_3_Week: String
var ILoveIt: String

required init?(_ map: Map) {

    tooLazy = ""
    times_1_3_Week = ""
    ILoveIt = ""

}

func mapping(map: Map) {

    tooLazy             <- map["too_lazy"]
    times_1_3_Week      <- map["times_1_3_week"]
    ILoveIt             <- map["i_love_it"]
}
}

class YASGymMemberQuestionChoices: Mappable {

var yes: String
var no: String


required init?(_ map: Map) {

    yes = ""
    no = ""

}

func mapping(map: Map) {

    yes             <- map["yes"]
    no              <- map["no"]

}
} 

この JSON 応答をマップする方法がわからないので、この JSON をマップする方法を教えてください。