public void GivenCustomerWhenCustomerIsPresentThenReturnInitialMonthlyPaymentAmount()
{
// Arrange
var mockPremiumCalculator = new Mock <IPremiumCalculator>();
mockPremiumCalculator.Setup(c => c.CalculateInitialMonthlyPaymentAmount(It.IsAny <decimal>(), It.IsAny <int>())).Returns(4.43M);
var mockCustomer = this.GetCustomerMock();
var premiumCalculatorBuilder = new PremiumCalculatorBuilder(mockPremiumCalculator.Object);
premiumCalculatorBuilder.SetCustomer(mockCustomer);
// Act
premiumCalculatorBuilder.CalculateInitialMonthlyPaymentAmount();
// Assert
mockPremiumCalculator.Verify(c => c.CalculateInitialMonthlyPaymentAmount(It.IsAny <decimal>(), It.IsAny <int>()), Times.Once);
Assert.AreEqual(4.43M, mockCustomer.InitialMonthlyPaymentAmount);
}