MultiPageEditorImpl implements MultiPageEditor { public void addPage(final Page page) { view.addPage(page); }  @PostConstruct void init(); void addPage(final Page page); void addPage(int index, final Page page); void disablePage(int index); void enablePage(int index); void selectPage(final int index); int selectedPage(); void addTabBarWidget(final IsWidget customWidget); @Override void clear(); @Override MultiPageEditorView getView(); @Override void addWidget(final IsWidget widget,
                          final String label); @Override Widget asWidget();  }
@Test public void testAddPageWithIndex() { final Page page = mock(Page.class); final int index = 1; editor.addPage(index, page); verify(view).addPage(index, page); }