code: public static <T> Single<Set<T>> values(String key, Class<T> vClazz) {
          return values(CacheService.CACHE_CONFIG_BEAN, key, vClazz);
      }
docs: retrial the cached set
  
  @param key    key
  @param vClazz value class
  @param <T>    generic type
  @return the value set