private static void RecalcTypeTrees <T>(TypeSelector <T> selector, Dictionary <Type, List <Pair> > group) where T : class { var validDefaults = group[typeof(T)]; selector.Clear(); foreach (var entry in validDefaults) { var att = entry.Item1; var ist = Activator.CreateInstance(entry.Item2); selector.AddValue(att.AssociatedType, att.UseInChildren, (T)ist); } }