+const char * const IMAGE_BORDER( "border" );
+const char * const PIXEL_ALIGNED_UNIFORM_NAME( "uPixelAligned" );
+const char * const ANIMATED_IMAGE_URLS_NAME("urls");
+const char * const BATCH_SIZE_NAME("batchSize");
+const char * const CACHE_SIZE_NAME("cacheSize");
+const char * const FRAME_DELAY_NAME("frameDelay");
+const char * const MASK_CONTENT_SCALE_NAME("maskContentScale");
+const char * const CROP_TO_MASK_NAME("cropToMask");
+const char * const LOAD_POLICY_NAME("loadPolicy");
+const char * const RELEASE_POLICY_NAME("releasePolicy");