public function validateBillingAgreement ()
    {
        $validateBillingAgreementRequest = new OffAmazonPaymentsService_Model_ValidateBillingAgreementRequest();
        $validateBillingAgreementRequest->setAmazonBillingAgreementId(
                $this->_amazonBillingAgreementId);
        $validateBillingAgreementRequest->setSellerId($this->_sellerId);
        
        return $this->_service->validateBillingAgreement($validateBillingAgreementRequest);
    }