@Override
    public String getId() {
        if (id == null) {
            id = new StringBuilder()
                .append(ID)
                .append(downsampler.getId())
                .append(decodeFormat.name())
                .toString();
        }
        return id;
    }
An {@link ResourceDecoder} that uses an
{@link Downsampler} to decode an {@link Bitmap} from an
{@link InputStream}.
core/src/main/java/com/bumptech/glide/load/resource/bitmap/StreamBitmapDecoder.java