public void Invalidate() { var site = new MockSite(); var root = new RootBox(new AssembledStyles()); root.Site = site; using (var lc = new LayoutCallbacks(root)) { lc.Invalidate(new Rectangle(10, 13, 17, 19)); lc.Invalidate(new Rectangle(9, 8, 5, 4)); Assert.That(site.RectsInvalidated, Is.Empty); } Assert.That(site.RectsInvalidated, Has.Member(new Rectangle(10, 13, 17, 19))); Assert.That(site.RectsInvalidated, Has.Member(new Rectangle(9, 8, 5, 4))); }