gan_node_html.php
protected function filter_checked() {
        $attr = $this->getAttribute('checked');
        if (is_array($attr))
            $attr = reset($attr);
        return strcasecmp($attr, 'checked') === 0;
    }
protected function filter_checked() {
        $attr = $this->getAttribute('checked');
        if (is_array($attr))
            $attr = reset($attr);
        return strcasecmp($attr, 'checked') === 0;
    }
Checks if a node matches css query filter ":checked"
@return bool
@see match()