code: private void destroySessionByToken(String id) {
  		System.out.println(new LogEntry("destroying session " + id));
  		synchronized (sessions) {
  			synchronized (sessionsMirror) {
  				StandardSession session = (StandardSession) sessions.get(id);
  				if (session != null) {
  					session.onDestruction();
  					sessions.remove(id);
  					sessionsMirror.remove(id);
  				}
  			}
  		}
  	}
docs: Unregisters a session from all collections so that it becomes eligible for garbage collection.
  
  @param id session id