Could you make this available as a NuGet package? Or would you accept a PR that does so? I am looking for a WPF treeview for my [expression tree visualizer](https://github.com/zspitz/ExpressionTreeVisualizer) with the following features: * Multiple selection * .NET Core support * Allows restyling such that even when the control is not in focus, it appears the same (i.e. not like this): 
Could you make this available as a NuGet package? Or would you accept a PR that does so?
I am looking for a WPF treeview for my expression tree visualizer with the following features:
Multiple selection
.NET Core support
Allows restyling such that even when the control is not in focus, it appears the same (i.e. not like this):