private IEnumerable <CollectionChange <ContentType, ContentType> > getCollectionChanges(IEnumerable <ContentType> items) { items = items ?? Enumerable.Empty <ContentType>(); //var cachedCollection = new List<TItem>(Collection); //var list = items.Take(5).ToList(); //items = list.ReturnInValue((x) => x.Shuffle()).Take(ThreadSafeRandom.Next(0, list.Count + 1)); var changes = ContentList.GetCollectionChanges(items, EqualityComparer) #if DEBUG .ToList() #endif ; return(changes); }