public function addSiteAliasUrls($idSite, $urls)
    {
        Piwik::checkUserHasAdminAccess($idSite);

        if (empty($urls)) {
            return 0;
        }

        if (!is_array($urls)) {
            $urls = array($urls);
        }

        $urlsInit = $this->getSiteUrlsFromId($idSite);
        $toInsert = array_merge($urlsInit, $urls);

        $urlsProperty = new Urls($idSite);
        $urlsProperty->setValue($toInsert);
        $urlsProperty->save();

        $inserted = array_diff($urlsProperty->getValue(), $urlsInit);

        $this->postUpdateWebsite($idSite);

        return count($inserted);
    }