protected static function normalizeRoute($route)
    {
        $route = Yii::getAlias((string) $route);
        if (strncmp($route, '/', 1) === 0) {
            // absolute route
            return ltrim($route, '/');
        }

        // relative route
        if (Yii::$app->controller === null) {
            throw new InvalidArgumentException("Unable to resolve the relative route: $route. No active controller is available.");
        }

        if (strpos($route, '/') === false) {
            // empty or an action ID
            return $route === '' ? Yii::$app->controller->getRoute() : Yii::$app->controller->getUniqueId() . '/' . $route;
        }

        // relative to module
        return ltrim(Yii::$app->controller->module->getUniqueId() . '/' . $route, '/');
    }