code: private static ResourceCache loadResourceCache() {
          try {
              return Optional.ofNullable(Bootstrap.getService(ResourceCache.class)).orElseGet(
                      DefaultResourceCache::new);
          } catch (Exception e) {
              LOG.log(Level.SEVERE, "Error loading ResourceCache instance.", e);
              return new DefaultResourceCache();
          }
      }
docs: Loads the cache to be used.
  
  @return the cache to be used, not null.