public void CalculateMonthlyPremium_Throw_When_ParameterIsNull() { var ex = Assert.Throws <BusinessException>(() => _calculatorService.CalculateMonthlyPremium(null)); Assert.IsTrue(Constants.CALCULATOR_PARAMETER_NULL_ERROR == ex.Message, "CalculateMonthlyPremium_Throw_When_ParameterIsNull success"); }