public static List<ChallengeRequest> parseRequest(Response response,
String header, Series<Parameter> httpHeaders) {
List<ChallengeRequest> result = new ArrayList<ChallengeRequest>();
if (header != null) {
result = new ChallengeRequestReader(header).readValues();
for (ChallengeRequest cr : result) {
// Give a chance to the authenticator helper to do further
// parsing
AuthenticatorHelper helper = Engine.getInstance().findHelper(
cr.getScheme(), true, false);