gtk:selection-model-unselect-range (model position n-items)

model -- a gtk:selection-model object
position -- an unsigned integer with the first item to unselect
n-items -- an unsigned integer with the number of items to unselect

True if this action was supported and no fallback should be tried. This does not mean the range was unselected.

Requests to unselect a range of items in the model.