+
+public let kPNKDidFinishSettingImageFromURLToImageView = "kPNKDidFinishSettingImageFromURLToImageView"
 
 private func imageCacheKeyFromURLRequest(request: NSURLRequest) -> String {
     return request.URL!.absoluteString

        if let cachedImage = ImageView.p_sharedImageCache.cachedImageForRequest(request) {
            image = cachedImage
            imageRequestOperation = nil
        } else {
            if let placeholder = placeholder {
                image = placeholder

        
        p_setImageWithRequest(request, placeHolderImage: placeholder)
    }
    
    private func postNotification() {
        executeOnMainThread {
            NSNotificationCenter.defaultCenter().postNotificationName(
                kPNKDidFinishSettingImageFromURLToImageView, 
                object: self,
                userInfo: nil
            )
        }
    }
}

