http://blog.shiqichan.com/using-afnetworking-sdwebimage-and-ohhttpstubs/
– sd_imageURL
– sd_setImageWithURL:
– sd_setImageWithURL:placeholderImage:
– sd_setImageWithURL:placeholderImage:options:
– sd_setImageWithURL:completed:
– sd_setImageWithURL:placeholderImage:completed:
– sd_setImageWithURL:placeholderImage:options:completed:
– sd_setImageWithURL:placeholderImage:options:progress:completed:
– sd_setImageWithPreviousCachedImageWithURL:andPlaceholderImage:options:progress:completed:
– sd_setAnimationImagesWithURLs:
– sd_cancelCurrentImageLoad
– sd_cancelCurrentAnimationImagesLoad