public override void StoreViewStateWithUndo(ModelItem modelItem, string key, object value)
        {
            object          oldValue = RetrieveViewState(modelItem, key);
            ViewStateChange vsChange = new ViewStateChange(this)
            {
                Item     = modelItem,
                Key      = key,
                OldValue = oldValue,
                NewValue = value,
            };
            ModelTreeManager modelTreeManager = this.context.Services.GetService <ModelTreeManager>();

            if (modelTreeManager != null)
            {
                modelTreeManager.AddToCurrentEditingScope(vsChange);
            }
        }
 public override void StoreViewStateWithUndo(ModelItem modelItem, string key, object value)
 {
     object oldValue = RetrieveViewState(modelItem, key);
     ViewStateChange vsChange = new ViewStateChange(this)
                                 {
                                     Item = modelItem,
                                     Key = key,
                                     OldValue = oldValue,
                                     NewValue = value,
                                 };
     ModelTreeManager modelTreeManager = this.context.Services.GetService<ModelTreeManager>();
     if (modelTreeManager != null)
     {
         modelTreeManager.AddToCurrentEditingScope(vsChange);
     }
 }