code: protected function getBizContent()
      {
          $content = [
              'out_biz_no'    => $this->trans_no,// 商户转账唯一订单号
              'payee_type'        => strtoupper($this->payee_type),// 收款方账户类型
              'payee_account'     => $this->payee_account,// 收款方账户
              'amount'     => $this->amount,
              'payer_show_name'       => $this->payer_show_name,
              'payer_real_name'    => $this->payer_real_name,
              'payee_real_name'          => $this->payee_real_name,
              'remark'       => $this->remark,
          ];
  
          return $content;
      }
docs: 业务请求参数的集合，最大长度不限，除公共参数外所有请求参数都必须放在这个参数中传递
  
  @return string