code: protected void doSaveRememberMeCookie(USER_ENTITY userEntity, USER_BEAN userBean, int expireDays, String cookieKey) {
          logger.debug("...Saving remember-me key to cookie: key={}", cookieKey);
          final String value = buildRememberMeCookieValue(userEntity, userBean, expireDays);
          final int expireSeconds = expireDays * 60 * 60 * 24; // cookie's expire, same as access token
          cookieManager.setCookieCiphered(cookieKey, value, expireSeconds);
      }
docs: Do save remember-me key to cookie.
  @param userEntity The selected entity of login user. (NotNull)
  @param userBean The user bean saved in session. (NotNull)
  @param expireDays The expire days of both access token and cookie value.
  @param cookieKey The key of the cookie. (NotNull)