CoreData 可以处理多态子类吗

Swift
import CoreData
class Animal: NSManagedObject {
    @NSManaged var name: String
}
class Dog: Animal {
    @NSManaged var breed: String
}
class Cat: Animal {
    @NSManaged var color: String
}
let context = // 获取CoreData的上下文
// 创建一个狗实例
let dog = NSEntityDescription.insertNewObjectForEntityForName("Dog", inManagedObjectContext: context) as! Dog
dog.name = "旺财"
dog.breed = "柯基"
// 创建一个猫实例
let cat = NSEntityDescription.insertNewObjectForEntityForName("Cat", inManagedObjectContext: context) as! Cat
cat.name = "咪咪"
cat.color = "橘黄色"
// 保存到数据库
do {
    try context.save()
} catch {
    print("保存失败：\(error)")
}
// 从数据库中获取所有动物
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Animal")
do {
    let animals = try context.fetch(fetchRequest) as! [Animal]
    for animal in animals {
        if let dog = animal as? Dog {
            print("狗的品种：\(dog.breed)")
        } else if let cat = animal as? Cat {
            print("猫的颜色：\(cat.color)")
        }
    }
} catch {
    print("获取动物失败：\(error)")
}