C# (CSharp) ChangeCollection.GroupBy примеры использования

Пример #1

 private List <Change> GetUniqueChanges(ChangeCollection changes)
 {
     return(changes
            .GroupBy(i => ((ChangeItem)i).ItemId,
                     (key, g) =>
                     g.OrderByDescending(e => e.Time).First()).OrderByDescending(c => c.Time)
            .ToList());
 }