private CacheKey getCacheKey() {
   final ImageRequest imageRequest = getImageRequest();
   final CacheKeyFactory cacheKeyFactory = mImagePipeline.getCacheKeyFactory();
   CacheKey cacheKey = null;
   if (cacheKeyFactory != null && imageRequest != null) {
     if (imageRequest.getPostprocessor() != null) {
       cacheKey = cacheKeyFactory.getPostprocessedBitmapCacheKey(imageRequest, getCallerContext());
     } else {
       cacheKey = cacheKeyFactory.getBitmapCacheKey(imageRequest, getCallerContext());
     }
   }
   return cacheKey;
 }