// the item at this index was previously selected:
int index = endOfTrueRange - 1;
// make sure that the item is unselected after inverting:
set.getCollectionModel().setRowKey(_getKey(index));
assertFalse("item is unselected", set.invert());
assertFalse("item is unselected", set.isContained());
// the item at this index was previously unselected:
index = endOfTrueRange + 1;
// make sure that the item is selected after inverting: