public function filterItemsForReview($items, $customerId, $order)
    {
        foreach ($items as $key => $item) {
            $productId = $item->getProduct()->getId();

            $collection = $this->reviewFactory->create()->getCollection()
                ->addCustomerFilter($customerId)
                ->addStoreFilter($order->getStoreId())
                ->addFieldToFilter('main_table.entity_pk_value', $productId);

            //remove item if customer has already placed review on this item
            if ($collection->getSize()) {
                unset($items[$key]);
            }
        }

        return $items;
    }