/// <summary>
        /// Handles changes to the Event property.
        /// </summary>
        private static void OnEventChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CommandBehaviorBinding binding = FetchOrCreateBinding(d);

            //check if the Event is set. If yes we need to rebind the Command to the new event and unregister the old one
            if (binding.Event != null && binding.Owner != null)
            {
                binding.Dispose();
            }
            //bind the new event to the command
            if (e.NewValue != null &&
                e.NewValue.ToString() != "")
            {
                binding.BindEvent(d, e.NewValue.ToString());
            }
        }
        /// <summary>
        /// Handles changes to the Command property.
        /// </summary>
        private static void OnCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CommandBehaviorBinding binding = FetchOrCreateBinding(d);

            binding.Command = (ICommand)e.NewValue;
        }
        /// <summary>
        /// Handles changes to the Action property.
        /// </summary>
        private static void OnActionChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CommandBehaviorBinding binding = FetchOrCreateBinding(d);

            binding.Action = (Action <object>)e.NewValue;
        }