PayPal\PayPalAPI\RefundTransactionReq::toXMLString PHP Method

    public function toXMLString()
    {
        $str = '';
        $str .= '<ns:RefundTransactionReq>';
        if ($this->RefundTransactionRequest != null) {
            $str .= '<ns:RefundTransactionRequest>';
            $str .= $this->RefundTransactionRequest->toXMLString();
            $str .= '</ns:RefundTransactionRequest>';
        }
        $str .= '</ns:RefundTransactionReq>';
        return $str;
    }