code: @Override
      protected StoreAccessorFactory configureFlashStoreAccessorFactory() {
          final StoreAccessorFactory candidate = configuredMessagesStoreAccessorFactory();
          return candidate == null ? super.configureFlashStoreAccessorFactory() : candidate;
      }
docs: /*
  (non-Javadoc)
  @see es.sandbox.ui.messages.spring.MessagesConfigurationSupport#configureMessagesStoreAccessorFactory()