@Test
  public void updateWithoutItems() throws Exception {
    equipWithItems(timeline, new Item("id", 20L) {});

    updater.update();

    verify(timeline, never()).setTopItem(any(Item.class));
  }
  @Test
  public void updateIfAboveTop() throws Exception {
    Item item = equipItemListWithItem();
    getItemUiControl(item).setLocation(0, fromTopOffset(-1));

    updater.update();

    verify(timeline, never()).setTopItem(item);
  }
  @Test
  public void updateIfBelowTopWithEqualTopItem() throws Exception {
    Item item = equipItemListWithItem();
    equipWithTopItem(timeline, item);
    getItemUiControl(item).setLocation(0, fromTopOffset(1));

    updater.update();

    verify(timeline, never()).setTopItem(item);
  }
  @Test
  public void updateIfBelowTopWithDifferentTopItem() throws Exception {
    Item item = equipItemListWithItem();
    equipWithTopItem(timeline, new Item("other", 30L) {});
    getItemUiControl(item).setLocation(0, fromTopOffset(1));

    updater.update();

    verify(timeline).setTopItem(item);
  }
  @Test
  public void updateIfItemUiControlIsNotShowing() throws Exception {
    Item item = equipWithItems(timeline, new Item("id", 20L) {});
    SwtItemUi<Item> itemUi = stubItemUi(displayHelper.createShell());
    map(itemUiMap, item, itemUi);
    getItemUiControl(item).setLocation(0, fromTopOffset(1));

    updater.update();

    verify(timeline, never()).setTopItem(item);
  }
  @Test
  public void updateWithoutItemUi() throws Exception {
    updater.update();

    verify(timeline, never()).setTopItem(any(Item.class));
  }