public function filterByPageTypeID($ptID)
    {
        $db = \Database::get();
        if (is_array($ptID)) {
            $this->query->andWhere(
                $this->query->expr()->in('pt.ptID', array_map([$db, 'quote'], $ptID))
            );
        } else {
            $this->query->andWhere($this->query->expr()->comparison('pt.ptID', '=', ':ptID'));
            $this->query->setParameter('ptID', $ptID, \PDO::PARAM_INT);
        }
    }