public CustomerDocumentsResponse CustomerDocuments(CustomerDocumentsRequest request)
        {
            if (request == null)
                throw new ArgumentNullException("request");

            return SendGetRequest<CustomerDocumentsRequest, CustomerDocumentsResponse>(request, "CustomerDocuments");
        }
        public CustomerDocumentsResponse CustomerDocuments(string merchantCustomerID, string merchantSessionID)
        {
            if (merchantCustomerID == null)
                throw new ArgumentNullException("merchantCustomerID");

            if (merchantSessionID == null)
                throw new ArgumentNullException("merchantSessionID");

            var request = new CustomerDocumentsRequest
            {
                MerchantCustomerID = merchantCustomerID,
                MerchantSessionID = merchantSessionID
            };
            return CustomerDocuments(request);
        }