protected function _renderQuery($query, $key = '')
    {
        $input = '';
        foreach ($query as $name => $value) {
            $name = $key ? $key.'['.$name.']' : $name;
            if (is_array($value)) {
                $input .= $this->_renderQuery($value, $name);
            } else {
                $input .= PHP_EOL.'<input type="hidden" name="'.$name.'" value="'.$value.'" />';
            }
        }
        
        return $input;
    }