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