When using ObservableRangeCollection.AddRange with IEnumerable, CollectionChanged event may be corrupt

[anders9ustafsson]

I have forked this project and created a unit test to illustrate my concern, see here.

ObservableRangeCollection.AddRange allows for a collection of type IEnumerable<T>. However, if the enumerable is invalidated upon traversal, the CollectionChanged event will yield an invalid NewItems list.

Question is, whether collection should be of type IEnumerable<T>, or if it should be limited e.g. to IList<T>?