@Override
  public int hashCode() {
    return ID.hashCode() + (int) (threshold * 1000) + (int) (quantizationLevels * 10);
  }
The threshold at which to apply the edges, default of 0.2.
The levels of quantization for the posterization of colors within the scene,
with a default of 10.0.
transformations/src/main/java/jp/wasabeef/glide/transformations/gpu/ToonFilterTransformation.java