set-selection in list-control<%>
Selects the item specified by the given index (items are indexed from
0). If the given index larger than the greatest index in the
list control, an exn:fail:contract exception is raised.
In a list box control, all other items are deselected, even if multiple
selections are allowed in the control. See also
select in list-box%.
The control's callback procedure is not invoked when this method is called.
The list control's selection can be changed by the user clicking the control, and such changes do not go through this method; use the control callback procedure (provided as an initialization argument) to monitor selection changes.