protected function parseOutputParams($params, $prefix = '')
    {
        $retval = array();
        foreach ($params as $key => $val) {
            if (is_array($val)) {
                $retval = array_merge($retval, $this->parseOutputParams($val, $prefix . $key . '.'));
            } else {
                $retval[$prefix . $key] = $val;
            }
        }
        return $retval;
    }