ProductPresenter extends PresenterWidget<ProductPresenter.MyView> implements BrandChangedEventHandler { @Override public void onBrandChanged(BrandChangedEvent event) { productDto.setBrand(event.getBrand()); getView().setProduct(productDto); } @Inject  ProductPresenter(
            EventBus eventBus,
            MyView view,
            PriceWidgetFactory priceWidgetFactory,
            CurrentBrand currentBrand,
            @Assisted ProductWidgetType productWidgetType,
            @Assisted ProductDto productDto); @Override void onBrandChanged(BrandChangedEvent event);  }
@Test public void onBrandChanged_updatesBrandInView() { BrandChangedEvent event = new BrandChangedEvent(BRAND); presenter.onBrandChanged(event); Brand actualBrand = getActualBrandPassedToView(); assertThat(actualBrand).isEqualTo(BRAND); }