class WeixinAuthorize::Token::RedisStore

def refresh_token
  super
  weixin_redis.hmset(client.redis_key, "access_token", client.access_token,
                                       "expired_at",   client.expired_at)
  weixin_redis.expireat(client.redis_key, client.expired_at.to_i-10) # 提前10秒超时
end