sub attr {
        my $node = shift;
        my $map = $node->getAttributes;
        for my $key ( keys %$map ) {
            next unless ( ref( $$map{$key} ) eq 'XML::DOM::Attr' );        
            my $val = $map->getNamedItem($key)->getValue;
            return "\[\@$key=\'$val\'\]";            
        }
        return undef;
    }