protected function responseAttributes($attributes)
    {
        if(!$attributes) return array();
        
        $ns = 'http://axschema.org/';

        $response = array();
        if(isset($this->data['ax'])) {
            $response['ns.ax'] = 'http://openid.net/srv/ax/1.0';
            foreach($attributes as $name => $value) {
                $alias = strtr($name, '/', '_');
                $response['ax.type.' . $alias] = $ns . $name;
                $response['ax.value.' . $alias] = $value;
            }
            return $response;
        }
        
        foreach($attributes as $name => $value) {
            if(!isset($this->ax_to_sreg[$name])) {
                continue;
            }
            
            $response['sreg.' . $this->ax_to_sreg[$name]] = $value;
        }
        return $response;
    }