docs: public long getLastChangedTimeMills(String serviceName) {
          ModelService service = null;
          try {
              service=lookupService(serviceName);
          }catch (ServiceException e){
              LOGGER.debug(String.format("Exception when lookup service by name=[%s], error=[%s]",serviceName,e.getMessage()));
          }
          return service == null ? -1L : service.getModifiedTime().getTime();
      }