public function parentIdInjection(array & $materialIds)
    {
        // Cut off related and table materials
        $this->query
            ->className('material')
            ->cond('MaterialID', $materialIds)
            ->cond('parent_id', 0)
            ->cond('Active', 1)
            ->order_by('Modyfied', 'DESC')
            ->fieldsNew('MaterialID', $materialIds);
    }