public Credentials getCredentials(AuthScheme scheme, String host, int port, boolean proxy)
throws CredentialsNotAvailableException {
URI uri = ResourceContext.get().getCurrentURI();
String username = ResourceContext.get().getCurrentUsername();
Set visitedURIs = ResourceContext.get().getVisitedURIs();
ResourceKey key = new ResourceKey(new ResourceURI(uri));
String message;
message = "\n";
message += "Authentication required.\n";
message += "realm: " + scheme.getRealm() + "\n";