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