public void AssignOnDeleteAction()
 {
     var hbm = new HbmKey();
     var km = new KeyMapper(typeof(Animal), hbm);
     km.OnDelete(OnDeleteAction.Cascade);
     hbm.ondelete.Should().Be.EqualTo(HbmOndelete.Cascade);
     km.OnDelete(OnDeleteAction.NoAction);
     hbm.ondelete.Should().Be.EqualTo(HbmOndelete.Noaction);
 }