public function validateBillingAgreement($request)
    {
        if (!$request instanceof OffAmazonPaymentsService_Model_ValidateBillingAgreementRequest) {
            $request = new OffAmazonPaymentsService_Model_ValidateBillingAgreementRequest($request);
        }
        $httpResponse = $this->_invoke($this->_convertValidateBillingAgreement($request));
        $response = OffAmazonPaymentsService_Model_ValidateBillingAgreementResponse::fromXML($httpResponse['ResponseBody']);
        $response->setResponseHeaderMetadata($httpResponse['ResponseHeaderMetadata']);
        return $response;
    }