public function generatePageList()
    {
        $this->now = new DateTime();
        $siteTreeIDList = array_merge([0], $this->getSiteTreesIDList());
        $connection = $this->getConnection();
        $rs = $connection->executeQuery('select cID from Pages where siteTreeID is null or siteTreeID in (' . implode(', ', $siteTreeIDList) . ')');
        while (($cID = $rs->fetchColumn()) !== false) {
            $page = Page::getByID($cID, 'ACTIVE');
            if ($page && $this->canIncludePageInSitemap($page)) {
                yield $page;
            }
        }
    }