public void SurfaceCollection_TestRetrieveAtId_ReturnsSurfaceWithUndefinedType() { var messenger = Substitute.For <IFrameworkMessenger>(); var collection = new GpuSurfaceCollection(messenger); AddToCollectionTwoInternalTwoRenderTargetsAndOneTexture(collection); var surface = collection.Retrieve(1); Assert.Equal(GpuSurfaceType.Undefined, surface.Type); }