private static function generatePoolClientId()
    {
        $now = ceil(microtime(true) * 10000);
        if (class_exists('Reaction', false)) {
            $rand = \Reaction::$app->security->generateRandomString(8);
        } else {
            $rand = static::randomStr();
        }
        return static::getClientIdPrefix() . $now . $rand;
    }