Swift 从firebase数据库检索嵌套数据

我必须从Firebase数据库中检索此数据并在UITableView中显示。我创建了一个Exercise类来存储该对象，然后，我必须将这些Exercise对象存储在exercisearray类型的Exercise中。我能够检索值，但无法存储在练习对象中。我该怎么做？请帮忙

运动班-

class Exercise: NSObject {


        var name: String?
        var bodyPart: String?
        var sets: String?
        var exerciseDescription: String?
        var image: String?

    init(name: String?, bodyPart: String?, sets: String?, exerciseDescription: String?, image: String? ) {
        self.name = name
        self.bodyPart = bodyPart
        self.sets = sets
        self.exerciseDescription = exerciseDescription
        self.image = image
    }
}

检索方法

class ExerciseList{

    func getExerciseDataFromDatabase(bodyPart: String){
            //var exercises: NSDictionary = [:]
            dbRef?.child("exercises/bodyParts").child(bodyPart).observeSingleEvent(of: .value, with: { (snapshot) in
                if let values = snapshot.value as? [String : AnyObject]{
                   print(values)
                }
            })
        }
    }