final class func와 동일한 방식class Friend{
	func sayHi(){
    	print("안녕")
    }
    final class func sayHo(){
    	print("호호")
    }
    static func sayHoo{
    	print("후후")
    }
}
class BestFriend: Friend{
	class override func sayHi(){
    	print("덮어씌운 안녕")
    }
    func sayHoo(){
    	print("덮어씌운 호호")
    }
}
let myFriend = Friend()
myFriend.sayHi() //안녕
Friend.sayHo() //호호
Friend.sayHoo() //후후
BestFriend.sayHi() //덮어씌운 안녕
BestFriend.sayHoo() //후후