public void RenderQueue_CopyStage_CatchNullInputs()
{
var commandQueue = Substitute.For <IRenderCommandQueue>();
IRenderQueue queue = new RenderQueue(commandQueue);
var source = Substitute.For <ITexture>();
var target = Substitute.For <IRenderTarget>();
Assert.Throws <Yak2DException>(() => { queue.Copy(null, target); });
Assert.Throws <Yak2DException>(() => { queue.Copy(source, null); });
}