public async Task SaveTipTransaction_ValidTip_PositiveTipTransactionIdAsync()
        {
            var myCalculatorViewModel = new CalculatorPageViewModel(myCalculator, myTipCalcTransaction, myTipDatabase)
            {
                TotalTxt   = "100.00",
                TipPercent = 10,
            };

            int result = await myCalculatorViewModel.SaveTipTransactionAsync();

            Assert.IsTrue(result > 0);
        }
        public async Task SaveTipTransaction_ValidTip_CalculatorAndTransactionValuesMatchAsync()
        {
            var myCalculatorViewModel = new CalculatorPageViewModel(myCalculator, myTipCalcTransaction, myTipDatabase)
            {
                TotalTxt   = "100.00",
                TipPercent = 10,
            };

            int result = await myCalculatorViewModel.SaveTipTransactionAsync();

            Assert.AreEqual(myCalculator.GrandTotal, myTipCalcTransaction.GrandTotal);
            Assert.AreEqual(myCalculator.NumberOfPersons, myTipCalcTransaction.NumOfPersons);
            Assert.AreEqual(myCalculator.Tip, myTipCalcTransaction.Tip);
            Assert.AreEqual(myCalculator.TipPercent, myTipCalcTransaction.TipPercent);
            Assert.AreEqual(myCalculator.Total, myTipCalcTransaction.Total);
            Assert.AreEqual(myCalculator.TotalPerPerson, myTipCalcTransaction.TotalPerPerson);
            Assert.AreEqual(false, myTipCalcTransaction.Split);
            Assert.IsNotNull(myTipCalcTransaction.Split);
        }