}


    @Override
    public String getUserDomain () {
        if ( this.realm == null && this.getSubject() != null ) {
            Set<Principal> pr = this.getSubject().getPrincipals();
            for ( Iterator<Principal> ite = pr.iterator(); ite.hasNext(); ) {
                try {
                    KerberosPrincipal entry = (KerberosPrincipal) ite.next();
                    return entry.getRealm();