setAvailableSortings example

$criteria->addExtension('sortings', $sortings);
    }

    public function process(Request $request, ProductListingResult $result, SalesChannelContext $context): void
    {
        /** @var ProductSortingCollection $sortings */
        $sortings = $result->getCriteria()->getExtension('sortings');
        $currentSortingKey = $this->getCurrentSorting($sortings, $request)->getKey();

        $result->setSorting($currentSortingKey);

        $result->setAvailableSortings($sortings);
    }

    private function getCurrentSorting(ProductSortingCollection $sortings, Request $request): ProductSortingEntity
    {
        $key = $request->get('order');

        if (!\is_string($key)) {
            throw ProductException::sortingNotFoundException('');
        }

        $sorting = $sortings->getByKey($key);