Inpsyde\MultilingualPress\Installation\Updater::import_site_relations PHP Method

    private function import_site_relations()
    {
        // TODO: With WordPress 4.6 + 2, just use `get_sites()`, and remove `$is_pre_4_6`.
        $is_pre_4_6 = version_compare($GLOBALS['wp_version'], '4.6-RC1', '<');
        $all_sites = $is_pre_4_6 ? wp_get_sites() : get_sites();
        foreach ($all_sites as $site) {
            // TODO: With WordPress 4.6 + 2, just use `$site->id`.
            $site_id = $is_pre_4_6 ? $site['blog_id'] : $site->id;
            $linked = get_blog_option($site_id, 'inpsyde_multilingual_blog_relationship', []);
            if ($linked) {
                $this->site_relations->insert_relations($site_id, $linked);
            }
            delete_blog_option($site_id, 'inpsyde_multilingual_blog_relationship');
        }
    }