### Question:
NotificationWidgetViewImpl extends Composite implements NotificationWidgetView { @Override public void hide() { dataProvider.getList().clear(); table.setRowCount(dataProvider.getList().size(), true); modal.hide(); }  @PostConstruct void init(); @Override void init(final NotificationWidgetView.Presenter presenter, List<NotificationRow> rows); @Override void delete(NotificationRow row); @Override void addOrEdit(NotificationRow row); @Override void setReadOnly(boolean readOnly); @Override void show(); void onSubscription(@Observes NotificationEvent event); @Override void refreshTable(); @Override void hide();  }### Answer:
@Test public void testHide() { notificationWidgetViewImpl.init(presenter, generateRows()); ListDataProvider<NotificationRow> dataProvider = getFieldValue(NotificationWidgetViewImpl.class, notificationWidgetViewImpl, "dataProvider"); notificationWidgetViewImpl.hide(); Assert.assertEquals(0, dataProvider.getList().size()); }