getHreflangDefaultDomainId example

public function load(HreflangLoaderParameter $parameter): HreflangCollection
    {
        $salesChannelContext = $parameter->getSalesChannelContext();

        if (!$salesChannelContext->getSalesChannel()->isHreflangActive()) {
            return new HreflangCollection();
        }

        $domains = $this->fetchSalesChannelDomains($salesChannelContext->getSalesChannel()->getId());

        if ($parameter->getRoute() === 'frontend.home.page') {
            return $this->getHreflangForHomepage($domains, $salesChannelContext->getSalesChannel()->getHreflangDefaultDomainId());
        }

        $pathInfo = $this->router->generate($parameter->getRoute(), $parameter->getRouteParameters(), RouterInterface::ABSOLUTE_PATH);

        $languageToDomainMapping = $this->getLanguageToDomainMapping($domains);
        $seoUrls = $this->fetchSeoUrls($pathInfo, $salesChannelContext->getSalesChannel()->getId(), array_keys($languageToDomainMapping));

        // We need at least two links         if (\count($seoUrls) <= 1) {
            return new HreflangCollection();
        }