public void WhenCalendarHasANonWorkingDayOfWeekReturnsItIsNotNonWorkingDayForOtherDay()
{
WorkingDatesCalendar argentineCalendar = new WorkingDatesCalendar();
argentineCalendar.AddNonWorkingDayOfWeek(DayOfWeek.Sunday);
Assert.IsFalse(argentineCalendar.IsNonWorkingDate(someMonday()));
}