public void RenderQueue_MixStage_CatchNullInputs()
{
var commandQueue = Substitute.For <IRenderCommandQueue>();
IRenderQueue queue = new RenderQueue(commandQueue);
var stage = Substitute.For <IMixStage>();
var mix = Substitute.For <ITexture>();
var target = Substitute.For <IRenderTarget>();
Assert.Throws <Yak2DException>(() => { queue.Mix(null, null, null, null, null, null, target); });
Assert.Throws <Yak2DException>(() => { queue.Mix(stage, null, null, null, null, null, null); });
}