@Override
    public String getId() {
        if (id == null) {
            id = bitmapEncoder.getId() + gifEncoder.getId();
        }
        return id;
    }
A {@link ResourceEncoder} that can encode either an {@link Bitmap} or
{@link GifDrawable}.
core/src/main/java/com/bumptech/glide/load/resource/gifbitmap/GifBitmapWrapperResourceEncoder.java