如何在Swift 3中将自定义类保存为CoreData实体的属性？

import CoreData

class CustomClass: NSObject, NSCoding {
    // 自定义类的属性
    var name: String
    var age: Int
    
    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }
    
    // 实现NSCoding协议的方法
    func encode(with coder: NSCoder) {
        coder.encode(name, forKey: "name")
        coder.encode(age, forKey: "age")
    }
    
    required init?(coder: NSCoder) {
        self.name = coder.decodeObject(forKey: "name") as? String ?? ""
        self.age = coder.decodeInteger(forKey: "age")
    }
}

// 生成的NSManagedObject子类
class Entity: NSManagedObject {
    @NSManaged var customObject: NSData?
    
    var customClass: CustomClass? {
        get {
            guard let data = customObject else {
                return nil
            }
            return NSKeyedUnarchiver.unarchiveObject(with: data as Data) as? CustomClass
        }
        set {
            if let newValue = newValue {
                let data = NSKeyedArchiver.archivedData(withRootObject: newValue)
                customObject = data as NSData
            } else {
                customObject = nil
            }
        }
    }
}