public void CustomDivisorShouldWork()
        {
            //Arrange
            var divisor = new CustomDivisor(3, "");

            //Act
            var result = divisor.IsFactorOf(9);

            //Assert
            result.Should().BeTrue();
        }
        public void ShouldCallTheSuppliedFactorFunction()
        {
            //Arrange
            var suppliedFactorFunctionWasCalled = false;

            Func <decimal, bool> badFactorFunc = num => suppliedFactorFunctionWasCalled = true;

            var divisor = new CustomDivisor("", badFactorFunc);

            //Act
            var message = divisor.IsFactorOf(9);

            //Assert
            message.Should().BeTrue();
        }