public void WhenCalendarHasTwoNonWorkingDayOfMonthThoseDaysAreNonWorkingDate()
{
WorkingDatesCalendar argentineCalendar = new WorkingDatesCalendar();
argentineCalendar.AddNonWorkingDayOfMonth(someJanuaryFirst());
argentineCalendar.AddNonWorkingDayOfMonth(someChrismas());
Assert.IsFalse(argentineCalendar.IsNonWorkingDate(someNotJanuaryFirst()));
}