protected async override Task <object> OnPerform()
        {
            var payload  = JsonConvert.SerializeObject(_paymentByVendorCouponContract);
            var content  = new StringContent(payload, Encoding.UTF8, ApplicationJSON);
            var response = await _restClient.PaymentByVendorCoupon(content);

            var data = await response.Content.ReadAsStringAsync();

            switch (response.StatusCode)
            {
            case HttpStatusCode.OK:
                var tenderSummary = new DeSerializer().MapTenderSummary(data);
                return(new Mapper().MapTenderSummary(tenderSummary));

            default:
                return(await HandleExceptions(response));
            }
        }