HTTP basic authorization with HTTP4?

Is there any way to send HTTP basic authorization(preemptive authentication)
to another web service(from HTTP4).

I have a proxy with Jetty consuming and HTTP4 producing.

Here is some sample code in the webservice documentation -

Options options = ipgstub._getServiceClient().getOptions();
HttpTransportProperties.Authenticator auth = new
HttpTransportProperties.Authenticator();
auth.setPreemptiveAuthentication(true);
auth.setUsername("WS111920._.1");
auth.setPassword("0WRtTq1K");
options.setProperty(HTTPConstants.AUTHENTICATE,auth);

Thanks!