Looking for a feature in NSOutlineView selection

FROM : Stéphane Sudre
DATE : Fri Nov 22 04:20:05 2002

Is it possible to know whether the selection is being extended or not
when you're in a NSOutlineView delegate method:

- (BOOL)outlineView:(NSOutlineView *)outlineView shouldSelectItem:(id)
inItem

I would like to base some of my testing in this method on the selection
being extending or not.