Model binding dynamic collections. III IClientSortable

gistfile1.cs

public interface IClientSortable
{
  int ClientOrder { get; set; }
}
public class SortableThing : IClientSortable
{
  public string Text { get; set; }
  public int Number { get; set; }
  public bool IsEven { get; private set; }
  public int ClientOrder { get; set; }

  public SortableThing() { }
  public SortableThing(Thing from)
  {
      Number = from.Number;
      Text = from.Text;
      IsEven = (from.Number % 2) == 0;
  }
  //mapping allowances...
}