Object[] elements = new Object[] { group1, news1, news2, news3, group2, news4, news5 };
NewsBrowserViewModel model = new NewsBrowserViewModel(null);
model.setInput(elements, 2);
Pair<List<Long>, List<Long>> revealed = model.revealPage(news1.getId(), 2);
assertTrue(revealed.getFirst().isEmpty());
assertTrue(revealed.getSecond().isEmpty());
assertEquals(2, model.getVisibleUnreadNews().size());
assertEquals(5L, model.getLastNews());