public async Task <IHttpActionResult> GetServiceHoursAndBillingChargesAsync(BabySitterCalculatorServiceModel model)
        {
            if (model.StartTime != null && model.EndTime != null)
            {
                BabySitterCalculatorServiceModel updatedModel = await Task.Run(() => BabySitterBillingCalculatorService.calculateServiceCharge(model));

                return(Ok(updatedModel));
            }
            else
            {
                return(BadRequest(ModelState));
            }
        }
        public void CalculateServiceChargeTest()
        {
            BabySitterCalculatorServiceModel inputBabySitterCalculatorServiceModel = new BabySitterCalculatorServiceModel();

            inputBabySitterCalculatorServiceModel.StartTime = "5:00 PM";
            inputBabySitterCalculatorServiceModel.EndTime   = "10:00 PM";
            BabySitterCalculatorServiceModel resultBabySitterCalculatorServiceModel = BabySitterBillingCalculatorService.calculateServiceCharge(inputBabySitterCalculatorServiceModel);

            Assert.AreEqual(resultBabySitterCalculatorServiceModel.BillingHours, 5);
            Assert.AreEqual(resultBabySitterCalculatorServiceModel.BillingCharge, 56);
        }