if ( searchControls.getReturningAttributes() != null ) { return; }
    protected void search( Name base, Map env, ExprNode filter,                           SearchControls searchControls )            throws NamingException    {        Invocation invocation = getInvocation();        if ( invocation.getState() == InvocationStateEnum.POSTINVOCATION )        {            SearchResultEnumeration enum ;            ResultFilteringEnumeration retval;            enum = ( SearchResultEnumeration ) invocation.getReturnValue();            retval = new ResultFilteringEnumeration( enum );            retval.addResultFilter( new ResultFilter() {                public boolean accept( DbSearchResult result )                {                    return filter( result.getAttributes() );                }            } );            invocation.setReturnValue( retval );        }    }