So I am pretty sure that up in the definition part I need to include something along the lines of:

```
xmlns:s="clr-namespace:System.Collections.Generic;assembly=?????" 

```

but I just do not know what to put in place of the ???'s.

What I want to do with the code is this:

```
<UserControl.DataContext>
    <ObjectDataProvider 
          MethodName="CreateNodes"
          ObjectType="{x:Type local:TreeViewModel}" >
        <ObjectDataProvider.MethodParameters>
            <s:List<T>>
                  {Binding Nodes}
            </s:List<T>>
        </ObjectDataProvider.MethodParameters>
    </ObjectDataProvider>
</UserControl.DataContext>

```

So that when I make the objectDataProvider call, I can pass the list in to the method that it is calling (CreateNodes)...

How do I go about doing this?

thanks!

**Edit - could be a fix?**

I just put this in the method, instead of passing in the list, it is just an app variable...I dont know if app variables are bad though 

```
  List<TNode> existingNodes;

  if (Application.Current.Properties.Contains("ExistingNodes")) existingNodes = Application.Current.Properties["ExistingNodes"] as List<TNode>;
  else existingNodes = new List<TNode>();

```