public function handleScheduleIndex(AbstractMappingEvent $event)
    {
        $document = $event->getDocument();
        if (!$document instanceof ArticleDocument) {
            if (!$document instanceof ArticlePageDocument) {
                return;
            }

            $document = $document->getParent();
        }

        $this->documents[$document->getUuid()] = [
            'uuid' => $document->getUuid(),
            'locale' => $document->getLocale(),
        ];
    }