topHeader.setupRequiredSize(new Size(0, 20));
final DummyView leftHeader = new DummyView();
leftHeader.setupRequiredSize(new Size(30, 0));
final View scrollBorder = new ScrollBorder(contentView, leftHeader, topHeader);
scrollBorder.setSize(new Size(100, 200));
Assert.assertEquals(new Size(300, 400), contentView.getSize());
Assert.assertEquals(new Size(300, 20), topHeader.getSize());
Assert.assertEquals(new Size(30, 400), leftHeader.getSize());