svcRef.setValue("ServiceInstance");
ServiceInstance si = client.createStub(ServiceInstance.class, svcRef);
sm = client.createStub(SessionManager.class,
si.getContent().getSessionManager());
sm.loginExtensionByCertificate(extKey, "en");
String ticket = sm.acquireSessionTicket(null);
logger.info("got session ticket using extension");
return ticket;
} catch (Exception e) {
logger.error("failed to get session ticket using extension", e);
return null;