public void CapitalPaymentShouldCalculateCorrectly(double rate, short numberPeriods, double presentValue, double futureValue,
DueDate due)
{
//Act
var correctSut = Math.Abs(Financial.CumPrinc(rate, numberPeriods, presentValue, 1, 1, PaymentDue.EndOfPeriod));
var sut = Math.Abs(FinancialCalculations.CapitalPayment(rate, 1, numberPeriods, presentValue, futureValue, due));
var isEqual = TestHelper.IsEqualDoubles(sut, correctSut);
//Assert
isEqual.Should().BeTrue();
}