callback "before node deselected" ?

I know about "NodeEventCallback selectionChanged:fnc"

but this returns nd: #(objectID) when selection changes to none/single selected or nd: #(objectID, objectID) when selection changes to any other object. Unfortunately switching between two objects returns always the same array, so I have no feedback which was selected and which was deselected.

I'm trying to echieve effect of printing name of the object at the moment it is deselected.

Any ideas?