code: public static <T> Maybe<T> get(String cacheKey, Class<T> clazz) {
          return get(CacheService.CACHE_CONFIG_BEAN, cacheKey, clazz);
      }
docs: get the cached object.
  
  @param cacheKey the key for the cache
  @param clazz    the class
  @param <T>      the type
  @return maybe event observable for the cached object, if the result is null, then the we will get a empty result.