public static ImageFilter get(ColorBlindness blindness) {
    if (blindness == ColorBlindness.protanopia) return protanopia;
    if (blindness == ColorBlindness.deuteranopia) return deuteranopia;
    if (blindness == ColorBlindness.tritanopia) return tritanopia;
    if (blindness == ColorBlindness.achromatopsia) return achromatopsia;
    return null;
  }
public static ImageFilter get(ColorBlindness blindness)