protected function getPages()
    {
        $pages = $this->site->getPages();
        $additionalPageIds = [];
        if (!empty($this->indexingConfiguration['additionalPageIds'])) {
            $additionalPageIds = GeneralUtility::intExplode(',', $this->indexingConfiguration['additionalPageIds']);
        }

        $pages = array_merge($pages, $additionalPageIds);
        sort($pages, SORT_NUMERIC);

        return $pages;
    }