Fwd: How associate session key with principal?

[Dmitry Polovka]

Hey guys, i don't want to dig sources really deep, and quick google 
search didn't provide me an answer.

How to get principal associated with session key/session id?
public class WebSessionManagerextends DefaultWebSessionManager
{

   @Override protected void onExpiration(Session s, ExpiredSessionException 
ese, SessionKey key)
   {
      // Before session is expired, how to get "principal" here by session 
key? super.onExpiration(s, ese, key);
   }
}