[DataContract]
    public class Option : DependencyObject 
    {

      [DataMember]
      public int Order 
      {
        get { return (int)GetValue(OrderProperty); }
        set { SetValue(OrderProperty, value); }
      }

      [DataMember]
      public static DependencyProperty OrderProperty =
        DependencyProperty.Register("Order", typeof(int), typeof(Option), new FrameworkPropertyMetadata(new PropertyChangedCallback(OnChanged)));


      public static void OnChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
      {
        Option Option = (Option)sender;
        if (e.Property == OrderProperty) Option.Order = (int)e.NewValue;
      }
    }