public static ResponseModel AttachPDF(InvoiceModel request)
        {
            Random        random        = new Random();
            ResponseModel responseModel = new ResponseModel();

            if (random.NextDouble() <= CONSTErrorPdfProb)
            {
                responseModel.success = false;
                responseModel.error   = Error.validate;
            }
            else
            {
                responseModel.CUFE    = (new Guid()).ToString();
                responseModel.success = SaveInvoiceProcess.AttachPDF(request);
                if (!responseModel.success)
                {
                    responseModel.error = Error.save;
                }
            }
            return(responseModel);
        }
        public static ResponseModel ProcesInvoice(InvoiceModel request)
        {
            Random        random        = new Random();
            ResponseModel responseModel = new ResponseModel();

            Thread.Sleep(CONSTSleepValue);
            if (random.NextDouble() <= CONSTErrorProb)
            {
                responseModel.success = false;
                responseModel.error   = Error.validate;
            }
            else
            {
                responseModel.CUFE    = (new Guid()).ToString();
                responseModel.success = SaveInvoiceProcess.Save(request);
                if (!responseModel.success)
                {
                    responseModel.error = Error.save;
                }
            }
            return(responseModel);
        }