public void GetAbsoluteYear()
 {
     Assert.AreEqual(1, Iso.GetAbsoluteYear(1, Era.Common));
     Assert.AreEqual(0, Iso.GetAbsoluteYear(1, Era.BeforeCommon));
     Assert.AreEqual(-1, Iso.GetAbsoluteYear(2, Era.BeforeCommon));
     Assert.AreEqual(Iso.MaxYear, Iso.GetAbsoluteYear(Iso.GetMaxYearOfEra(Era.Common), Era.Common));
     Assert.AreEqual(Iso.MinYear, Iso.GetAbsoluteYear(Iso.GetMaxYearOfEra(Era.BeforeCommon), Era.BeforeCommon));
 }