docs: public static boolean isCategoryOnlyCriteria(final Criteria criteria) {
  
          return  isEmpty(criteria.getAliases()) &&      // we are not subscribing to alias topic (yet)
                  isEmpty(criteria.getDeviceTypes()) &&  // we are not subscribing to device type topic (yet)
                  !isEmpty(criteria.getCategories());    // BUT! categories are mapped to topics
      }