ItemUiList { public boolean isTimelineEmpty() { return itemUiMap.isTimelineEmpty(); } protected  ItemUiList( ItemUiMap<T, U> itemUiMap, BackgroundProcessor backgroundProcessor ); boolean isTimelineEmpty(); void fetchInBackground( FetchOperation operation ); void fetch( FetchOperation operation ); void update();  }
@Test public void isTimelineEmpty() { when( itemUiMap.isTimelineEmpty() ).thenReturn( true ); boolean actual = itemUiList.isTimelineEmpty(); assertThat( actual ).isTrue(); }