public void HSLtoRGB_ArgumentNullException()
 {
     Assert.Throws <ArgumentNullException>(() => ColorModelConverter.HSLtoRGB(null));
 }
        public void HSLtoRGB_CorrectCalculation(HSL hsl, RGB expected)
        {
            RGB result = ColorModelConverter.HSLtoRGB(hsl);

            Assert.That(result, Is.EqualTo(expected));
        }