weblogic.security.acl.internal.AuthenticatedSubject not
resolved

Hi guys,

when I try to implement that code:

CallbackHandler handler = new URLCallbackHandler(username,
                                                           password);
Subject mySubject =
        weblogic.security.services.Authentication.login(handler);
weblogic.servlet.security.ServletAuthentication.runAs(mySubject, request);
// Where request is the httpservletrequest object.

in my servlet I get that issue in workshop 9.2:

The type weblogic.security.acl.internal.AuthenticatedSubject cannot be resolved.
It is indirectly 
 referenced from required .class files

Any idea??

Thanks a lot