网络不好导致的卡在广告页

[MadeBugs]

private func image(url: URL, cache: Bool, completion:@escaping (UIImage?)->()) {

        guard let imageData = try? Data(contentsOf: url) else {
            return
        }
        if cache {
            saveImage(imageData, url: url, completion: nil)/// 存储
        }
        let image = self.image(data: imageData)
        completion(image)
    
}

在网络不好的情况下，下载缓慢，会卡在这里，