如何擦除CALayer的一部分？

import UIKit

// 创建需要擦除的图层
let layerToErase = CALayer()
layerToErase.frame = CGRect(x: 50, y: 50, width: 100, height: 100)
layerToErase.backgroundColor = UIColor.red.cgColor

// 创建用于擦除的新图层
let eraseLayer = CAShapeLayer()
eraseLayer.frame = layerToErase.bounds

// 创建擦除形状的路径
let erasePath = UIBezierPath(rect: CGRect(x: 20, y: 20, width: 60, height: 60))

// 设置新图层的路径和混合模式
eraseLayer.path = erasePath.cgPath
eraseLayer.fillColor = UIColor.clear.cgColor
eraseLayer.blendMode = .clear

// 将新图层添加到需要擦除的图层的父图层上
layerToErase.superlayer?.addSublayer(eraseLayer)