partial         void CopyExtraPropertiesToClone(NotificationMessage clone, bool includeLocalProperties);
 public NotificationMessage Clone(bool includeLocalProperties)
 {
     var c = new NotificationMessage
             {
                 HtmlSummary = HtmlSummary,
                 IconClass = IconClass,
                 IconTitle = IconTitle,
                 Id = Id,
                 OccurredAt = OccurredAt,
                 Viewed = Viewed,
             };
     CopyExtraPropertiesToClone(c, includeLocalProperties);
     return c;
 }