code: public static Single<Long> decrement(CacheConfigBean cacheConfigBean, String cacheKey) {
          return SingleRxXian.call(CacheService.CACHE_SERVICE, "cacheDecrement", new JSONObject() {{
              put("cacheConfig", cacheConfigBean);
              put("key", cacheKey);
          }}).map(response -> {
              response.throwExceptionIfNotSuccess();
              return (long) response.getData();
          });
      }
docs: decrement
  
  @param cacheConfigBean datasource configuration
  @param cacheKey        key
  @return the result value after decrement, or error.