class NotificationsEditorWidget extends Composite implements HasValue<NotificationTypeListValue> {

    void showNotificationsDialog() {
        notificationWidget.setValue(notificationTypeListValue.getValues()
                                            .stream()
                                            .map(NotificationRow::new)
                                            .collect(Collectors.toList()),
                                    true);

        notificationWidget.setCallback(data -> setValue(data,
                                                        true));
        notificationWidget.show();
    }

}