public void Stages_DestroyStage_CatchNull() { var renderStageManager = Substitute.For <IRenderStageManager>(); var viewportManager = Substitute.For <IViewportManager>(); var renderStageVisitor = Substitute.For <IRenderStageVisitor>(); IStages stages = new Stages(renderStageManager, viewportManager, renderStageVisitor); Assert.Throws <Yak2DException>(() => { stages.DestroyStage(null); }); }