private void RunToArrayOnAllCollectionTypes <T>(T[] items, Action <T[]> validation) { validation(Enumerable.ToArray(items)); validation(Enumerable.ToArray(new List <T>(items))); validation(new TestEnumerable <T>(items).ToArray()); validation(new TestReadOnlyCollection <T>(items).ToArray()); validation(new TestCollection <T>(items).ToArray()); }