protected function _appendHttpStatusAndRate($reply, $httpstatus, $rate)
  {
    switch ($this->_return_format) {
      case CODEBIRD_RETURNFORMAT_ARRAY:
        $reply['httpstatus'] = $httpstatus;
        $reply['rate']       = $rate;
        break;
      case CODEBIRD_RETURNFORMAT_OBJECT:
        $reply->httpstatus = $httpstatus;
        $reply->rate       = $rate;
        break;
      case CODEBIRD_RETURNFORMAT_JSON:
        $reply             = $this->_json_decode($reply);
        $reply->httpstatus = $httpstatus;
        $reply->rate       = $rate;
        $reply             = json_encode($reply);
        break;
    }
    return $reply;
  }