* The HTTP <a
   * href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-DNS-Prefetch-Control">{@code
   * X-DNS-Prefetch-Control}</a> header controls DNS prefetch behavior. Value can be "on" or "off".
   * By default, DNS prefetching is "on" for HTTP pages and "off" for HTTPS pages.
   */
  public static final String X_DNS_PREFETCH_CONTROL = "X-DNS-Prefetch-Control";
  /**

        requests.clear();

        PluginPrefixResult result = processResults(request, trace, results, requests);

        if (result != null) {
            return result;
        }

        // second try, refetch all (possibly outdated) metadata that wasn't updated in the first attempt

        if (!request.getRepositorySession().isOffline() && !requests.isEmpty()) {

            ASN1ObjectIdentifier[] rm = tinit.getMechanisms();
            this.remoteMechs = rm;
            ASN1ObjectIdentifier prefMech = rm[ 0 ];
            // only use token if the optimistic mechanism is supported
            if ( this.mechContext.isSupported(prefMech) ) {
                inputToken = tinit.getMechanismToken();
            }
            else {
                ASN1ObjectIdentifier found = null;