code: @Override
      protected Level[] configureIncludedLevels() {
          final Level[] levels = configuredIncludedLevels();
          return levels == null ? super.configureIncludedLevels() : levels;
      }
docs: /*
  (non-Javadoc)
  @see es.sandbox.ui.messages.spring.MessagesConfigurationSupport#configureIncludedLevels()