PayPal\PayPalAPI\SetExpressCheckoutReq::toXMLString PHP Method

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