How to access fields in org.apache.cxf.transport.Session?

Hello,

I have an Interceptor like this:

public void handleMessage(Message msg) throws Fault {

BindingOperationInfo binding =
msg.getExchange().getBindingOperationInfo();

if (binding != null) {
String requestUri = (String)msg.get(Message.REQUEST_URI);
Session session = msg.getExchange().getSession();
...

How do I access fields of the Session, like a Session ID? All that
org.apache.cxf.transport.Session offers is one method get(Object key). How
do I use that?

cheers,
F.