[concrete5][V8][Express] Get Page by Express Attribute Value

Page.php

<?php
namespace Application\Concrete\Express\Service;

use Concrete\Core\Application\Application;
use Concrete\Core\Attribute\Category\PageCategory;
use Concrete\Core\Cache\Level\RequestCache;
use Concrete\Core\Database\Connection\Connection;
use Concrete\Core\Database\DatabaseManager;
use Concrete\Core\Entity\Attribute\Key\PageKey;
use Concrete\Core\Entity\Express\Entry;
use Doctrine\DBAL\Query\QueryBuilder;

/**
 * A helper class for relations with Express and Page
 *
 * @package Application\Concrete\Express\Service
 */
class Page
{
    /** @var Application $app */
    protected $app;
    /** @var RequestCache $cache */
    protected $cache;

    public function __construct(Application $application)
    {
        $this->app = $application;
        $this->cache = $application->make('cache/request');
    }

    /**
     * @param PageKey $ak
     * @param Entry $entry
     * @return \Concrete\Core\Page\Page
     */
    public function getPageByExpressAttributeValue(PageKey $ak, Entry $entry)
    {
        $item = $this->cache->getItem(sprintf('page/express/entry/%d', $entry->getID()));
        $cID = $item->get();
        if ($item->isMiss()) {
            $category = $this->app->make(PageCategory::class);
            /** @var Connection $db */
            $db = $this->app->make(DatabaseManager::class)->connection();
            /** @var QueryBuilder $qb */
            $qb = $db->createQueryBuilder();
            $qb
                ->select('cID')
                ->from($category->getIndexedSearchTable())
                ->where('ak_' . $ak->getAttributeKeyHandle() . ' = ?')
                ->setParameter(0, $entry->getID())
            ;
            $sth = $qb->execute();
            $cID = $sth->fetchColumn();
            $this->cache->save($item->set($cID));
        }

        return \Concrete\Core\Page\Page::getByID($cID);
    }
}