private function getPageTitleProperty(ArticleInterface $document)
    {
        $metadata = $this->structureMetadataFactory->getStructureMetadata(
            'article',
            $document->getStructureType()
        );

        if ($metadata->hasPropertyWithTagName(self::PAGE_TITLE_TAG_NAME)) {
            return $metadata->getPropertyByTagName(self::PAGE_TITLE_TAG_NAME);
        }

        if ($metadata->hasProperty(self::PAGE_TITLE_PROPERTY_NAME)) {
            return $metadata->getProperty(self::PAGE_TITLE_PROPERTY_NAME);
        }

        return null;
    }