如何为派生的每个SKSpriteNode添加单独的整数变量

import SpriteKit

class CustomSpriteNode: SKSpriteNode {
    var customInt: Int
    
    init(texture: SKTexture?, color: UIColor, size: CGSize, customInt: Int) {
        self.customInt = customInt
        super.init(texture: texture, color: color, size: size)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

let spriteNode1 = CustomSpriteNode(texture: nil, color: .red, size: CGSize(width: 100, height: 100), customInt: 1)
let spriteNode2 = CustomSpriteNode(texture: nil, color: .blue, size: CGSize(width: 100, height: 100), customInt: 2)
let spriteNode3 = CustomSpriteNode(texture: nil, color: .green, size: CGSize(width: 100, height: 100), customInt: 3)

// 添加到场景中
self.addChild(spriteNode1)
self.addChild(spriteNode2)
self.addChild(spriteNode3)

// 获取customInt值
let intValue = spriteNode1.customInt

// 修改customInt值
spriteNode2.customInt = 5