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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def unselect_item(self, item):
 """ Unselect an item. """

        self.queue_draw_item(item)
        if item.model in self._selection:
            with self._suppress_selection_events():
                self._selection.remove(item.model)
            self.emit('selection-changed', self._get_selected_items())