code: protected function retData(array $data)
      {
          if ($this->config->returnRaw) {
              $data['channel'] = Config::WX_TRANSFER;
              return $data;
          }
  
          // 请求失败，可能是网络
          if ($data['return_code'] != 'SUCCESS') {
              return $retData = [
                  'is_success'    => 'F',
                  'error' => $data['return_msg'],
                  'channel' => Config::WX_TRANSFER,
              ];
          }
  
          // 业务失败
          if ($data['result_code'] != 'SUCCESS') {
              return $retData = [
                  'is_success'    => 'F',
                  'error' => $data['err_code_des'],
                  'channel' => Config::WX_TRANSFER,
              ];
          }
  
          // 正确
          return $this->createBackData($data);
      }
docs: 处理通知的返回数据
  @param array $data
  @return mixed
  @author helei