private void ValidateUrl()
        {
            StringValidator validator = new StringValidator(nameof(_configuration.Url), _configuration.Url);

            validator.IsNotNullOrWhiteSpace();
            validator.DoesNotContainSeparator();
        }
        private void ValidateMerchantId()
        {
            StringValidator validator = new StringValidator(nameof(_configuration.MerchantId), _configuration.MerchantId);

            validator.IsNotNullOrWhiteSpace();
            validator.IsNotLongerThan(15);
            validator.IsAlphanumeric();
        }
        private void ValidateTransactionReference()
        {
            StringValidator validator = new StringValidator(nameof(_request.TransactionReference), _request.TransactionReference);

            validator.IsNotNullOrWhiteSpace();
            validator.IsNotLongerThan(32);
            validator.IsAlphanumeric();
        }
        private void ValidateReturnUrl()
        {
            StringValidator validator = new StringValidator(nameof(_request.ReturnUrl), _request.ReturnUrl);

            validator.IsNotNullOrWhiteSpace();
            validator.DoesNotContainSeparator();
            validator.IsNotLongerThan(512);
        }
        private void ValidateData()
        {
            StringValidator validator = new StringValidator(nameof(_postData.Data), _postData.Data);

            validator.IsNotNullOrWhiteSpace();
        }
        private void ValidateSecretKey()
        {
            StringValidator validator = new StringValidator(nameof(_configuration.SecretKey), _configuration.SecretKey);

            validator.IsNotNullOrWhiteSpace();
        }