public void addEventListener(EventListener listener)
    throws IllegalArgumentException
    {
        
        if (listener instanceof HttpSessionAttributeListener)
            _sessionAttributeListeners.add(listener);
        if (listener instanceof HttpSessionListener)
            _sessionListeners.add(listener);
    }
public void addEventListener ( EventListener listener ) throws IllegalArgumentException { if ( listener instanceof HttpSessionAttributeListener ) _sessionAttributeListeners . add ( listener ) ; if ( listener instanceof HttpSessionListener ) _sessionListeners . add ( listener ) ; }
/* ------------------------------------------------------------