如何使用CGContextDrawTiledImage平铺图像？

import UIKit

class TiledImageView: UIView {
    var image: UIImage?

    override func draw(_ rect: CGRect) {
        guard let image = image else { return }
        let context = UIGraphicsGetCurrentContext()
        context?.saveGState()
        let pattern = UIColor(patternImage: image)
        context?.setFillColor(pattern.cgColor)
        context?.fill(rect)
        context?.restoreGState()
    }
}

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let tiledImageView = TiledImageView(frame: view.bounds)
        tiledImageView.image = UIImage(named: "tile_image")
        view.addSubview(tiledImageView)
    }
}