如何以每秒1像素的速度增加SKShapeNode的半径？

import SpriteKit

class GameScene: SKScene {
    var circleNode: SKShapeNode!

    override func didMove(to view: SKView) {
        // 创建一个初始半径为10的圆形节点
        circleNode = SKShapeNode(circleOfRadius: 10)
        circleNode.position = CGPoint(x: frame.midX, y: frame.midY)
        circleNode.fillColor = .blue
        addChild(circleNode)

        // 计算目标半径（假设目标半径为100）
        let targetRadius = CGFloat(100)
        let currentRadius = circleNode.path?.boundingBox.size.width ?? 0

        // 计算需要增加的总像素数
        let totalIncrease = targetRadius - currentRadius

        // 创建一个每秒增加1像素的动作
        let increaseAction = SKAction.customAction(withDuration: TimeInterval(totalIncrease)) { [weak self] (_, _) in
            guard let self = self else { return }
            let currentPath = self.circleNode.path
            let currentRect = currentPath?.boundingBox ?? CGRect.zero
            let newRadius = min(currentRect.width + 1, targetRadius)
            self.circleNode.path = UIBezierPath(ovalIn: CGRect(x: -newRadius / 2, y: -newRadius / 2, width: newRadius, height: newRadius)).cgPath
        }

        // 运行动作
        circleNode.run(increaseAction)
    }
}