class CachingSubsystemRegistry implements SubsystemRegistry {

   @Override
   public Optional<SubsystemExecutor> loadByPlace(UUID placeId) {
      if(placeId == null) {
         return Optional.empty();
      }
      try {
         SubsystemExecutor executor = executors.get(placeId, () -> doLoadByPlace(placeId));
         return Optional.of(executor);
      }
      catch(Exception e) {
         logger.debug("Unable to load cache entry for placeId {}", placeId, e);
         return Optional.empty();
      }
   }

   @Inject public  CachingSubsystemRegistry(
         SubsystemFactory factory,
         PlaceDAO placeDao,
         ModelDao modelDao,
         PlacePopulationCacheManager populationCacheMgr,
         SubsystemConfig config
   );

}