/**
  * {@inheritDoc}
  *
  * <p>Overridden to make it visible to other classes in this package.
  */
 @Override
 protected void unregisterSession(Endpoint endpoint, WsSession wsSession) {
   if (wsSession.getUserPrincipal() != null && wsSession.getHttpSessionId() != null) {
     unregisterAuthenticatedSession(wsSession, wsSession.getHttpSessionId());
   }
   super.unregisterSession(endpoint, wsSession);
 }