public void GetColorTypeDescription()
        {
            PngDirectory  directory  = new PngDirectory(PngChunkType.IHDR);
            PngDescriptor descriptor = new PngDescriptor(directory);

            directory.Set(PngDirectory.TagColorType, 6);
            Assert.Equal("True Color with Alpha", descriptor.GetColorTypeDescription());
            Assert.Equal("True Color with Alpha", directory.GetDescription(PngDirectory.TagColorType));
        }