public void GivenCustomerWhenCustomerIsPresentThenReturnTotalPremium()
        {
            // Arrange
            var mockPremiumCalculator = new Mock <IPremiumCalculator>();

            mockPremiumCalculator.Setup(c => c.CalculateTotalPremium(It.IsAny <decimal>())).Returns(52.5M);
            var mockCustomer             = this.GetCustomerMock();
            var premiumCalculatorBuilder = new CustomerBuilder(mockPremiumCalculator.Object);

            premiumCalculatorBuilder.Set(mockCustomer);

            // Act
            premiumCalculatorBuilder.CalculateTotalPremium();

            // Assert
            mockPremiumCalculator.Verify(c => c.CalculateTotalPremium(It.IsAny <decimal>()), Times.Once);
            Assert.AreEqual(52.5M, mockCustomer.TotalPremium);
        }