internal ArtistGrouped(IList<IAlbum> albums)
 {
     var Int = albums.LiveSelectManyTuple((a) => a.Artists);
     var Int2 = Int.LiveToLookUp((t) => t.Item2, (t) => t.Item1);
     _Coll = Int2.LiveOrderBy((a) => a.Key.Name).LiveSelect(el => new ComposedObservedCollection<IArtist, IAlbum>(el.Key, el.Collection));
     _ToClean = Int;
     _ToClean2 = Int2;
 }