DowloadImageWithURL与SDWebImage

Question

我在SDWebImage的完成块上遇到这种错误。我的目标是下载图像。这是我的代码：

let manager: SDWebImageManager = SDWebImageManager.sharedManager()
manager.downloadImageWithURL(NSURL(string: feedDetails.thumbnail), options: [],
    progress: {(receivedSize: Int, expectedSize: Int) -> Void in
    },
    completed: {(image: UIImage, data: NSData, error: NSError, finished: Bool) -> Void in
    }
)

这是我遇到的错误：

  

无法转换类型＆＃39;（UIImage，NSData，NSError，Bool）的值 - ＆gt;虚空＆＃39;   预期参数类型＆＃39; SDWebImageCompletionWithFinishedBlock！＆＃39;