public void GetDueDateWithHolidayShouldOnlyEnumerateWorkingTime(
                DateTime startTime,
                TimeSpan workingHours,
                DateTime expectedDueDate,
                string expectation)
            {
                // Arrange
                var service = new ServicePlannerManager(Common.MockWorkDays(), Common.MockHolidayPeriods());

                // Act
                var result = service.GetDueDate(startTime, workingHours);

                // Assert - 
                Assert.AreEqual(expectedDueDate, result, expectation);
            }