private function addFilterByParent(ProductCollection $productCollection, $parentId)
    {
        $tableProductRelation = $productCollection->getTable('catalog_product_relation');
        $productCollection->getSelect()->join(
            ['pr' => $tableProductRelation],
            'e.entity_id = pr.child_id'
        )->where('pr.parent_id = ?', $parentId);
    }