public void TestCanvasDrawsPointCorrectly()
{
screen = MockRepository.GenerateStub<Screen>();
var canvas = new Canvas(screen);
var layerId = canvas.CreateLayer();
var layer = canvas.GetLayer(layerId);
layer.DrawPoint(20, 20, Colour.LightBlue);
screen.Expect(s => s.DrawPoint(20, 20, Colour.LightBlue)).Repeat.Once();
canvas.Redraw();
screen.VerifyAllExpectations();
}