Volume Rendering Cropping "ON"

I was implementing the volume rendering module using python and I could not get the ROI volume cropping as shown here;

displayNode.CroppingEnabled = True

But I did get it working using this version of the call;

displayNode.SetAndObserveROINodeID( roiNode.GetID() )

I also had to set the ROI to visible for these to apply.

Perhaps the script repo. is outdated?
I saw a few posts on volume rendering but no questions on enabling cropping, so I thought I would share.