code: public static Set<String> cacheNames(Config config) {
      return config.hasPath("caffeine.jcache")
          ? Collections.unmodifiableSet(config.getObject("caffeine.jcache").keySet())
          : Collections.emptySet();
    }
docs: Retrieves the names of the caches defined in the configuration resource.
  
  @param config the configuration resource
  @return the names of the configured caches