/// <summary>
 /// Defines changes to apply
 /// </summary>
 protected override void OnRedo()
 {
     Lane.UpdateFlow(Flow);
     OnString = "Flow change from {0} to {1}";
 }
 /// <summary>
 /// Defines changes to remove
 /// </summary>
 protected override void OnUndo()
 {
     Lane.UpdateFlow(previousFlow);
     OnString = "Flow change from {1} to {0}";
 }