     public func kf_setImageWithURL(URL: NSURL,
                         forState state: UIControlState) -> RetrieveImageTask
     {
-        return kf_setImageWithURL(URL, forState: state, placeHolderImage: nil, options: KingfisherOptions.None, progressBlock: nil, completionHandler: nil)
+        return kf_setImageWithURL(URL, forState: state, placeholderImage: nil, options: KingfisherOptions.None, progressBlock: nil, completionHandler: nil)
     }
     
     public func kf_setImageWithURL(URL: NSURL,
                         forState state: UIControlState,
                       placeholderImage: UIImage?) -> RetrieveImageTask
     {
-        return kf_setImageWithURL(URL, forState: state, placeHolderImage: placeHolderImage, options: KingfisherOptions.None, progressBlock: nil, completionHandler: nil)
+        return kf_setImageWithURL(URL, forState: state, placeholderImage: placeholderImage, options: KingfisherOptions.None, progressBlock: nil, completionHandler: nil)
     }
     
     public func kf_setImageWithURL(URL: NSURL,

                      placeholderImage: UIImage?,
                               options: KingfisherOptions) -> RetrieveImageTask
    {
        return kf_setImageWithURL(URL, forState: state, placeHolderImage: placeHolderImage, options: options, progressBlock: nil, completionHandler: nil)
    }
    
    public func kf_setImageWithURL(URL: NSURL,

    public func kf_setBackgroundImageWithURL(URL: NSURL,
                                  forState state: UIControlState) -> RetrieveImageTask
    {
        return kf_setBackgroundImageWithURL(URL, forState: state, placeholderImage: nil, options: KingfisherOptions.None, progressBlock: nil, completionHandler: nil)
    }
    
    public func kf_setBackgroundImageWithURL(URL: NSURL,
                                  forState state: UIControlState,
                                placeholderImage: UIImage?) -> RetrieveImageTask
    {
        return kf_setBackgroundImageWithURL(URL, forState: state, placeholderImage: placeholderImage, options: KingfisherOptions.None, progressBlock: nil, completionHandler: nil)
    }
    
    public func kf_setBackgroundImageWithURL(URL: NSURL,
                                  forState state: UIControlState,
                                placeholderImage: UIImage?,
                                         options: KingfisherOptions) -> RetrieveImageTask
    {
        return kf_setBackgroundImageWithURL(URL, forState: state, placeholderImage: placeholderImage, options: options, progressBlock: nil, completionHandler: nil)
    }
    
    public func kf_setBackgroundImageWithURL(URL: NSURL,
                                  forState state: UIControlState,
                                placeholderImage: UIImage?,
                                         options: KingfisherOptions,
                               completionHandler: CompletionHandler?) -> RetrieveImageTask
    {
        return kf_setBackgroundImageWithURL(URL, forState: state, placeholderImage: placeholderImage, options: options, progressBlock: nil, completionHandler: completionHandler)
    }
    
    public func kf_setBackgroundImageWithURL(URL: NSURL,
                                  forState state: UIControlState,
                                placeholderImage: UIImage?,
                                         options: KingfisherOptions,
                                   progressBlock: DownloadProgressBlock?,
                               completionHandler: CompletionHandler?) -> RetrieveImageTask
    {
        setBackgroundImage(placeholderImage, forState: state)
        kf_setBackgroundWebURL(URL, forState: state)
        let task = KingfisherManager.sharedManager.retrieveImageWithURL(URL, options: options, progressBlock: { (receivedSize, totalSize) -> () in
            if let progressBlock = progressBlock {
                dispatch_async(dispatch_get_main_queue(), { () -> Void in
