RowKeySetImpl set1 = _createKeySet(true);
set1.setCollectionModel(ModelUtils.toCollectionModel(infinite));
set1.remove(k3);
RowKeySetImpl set2 = _createKeySet(false);
set2.addAll(set1);
assertTrue(set2.contains(k1));
assertTrue(set2.contains(k2));
assertFalse(set2.contains(k3));
// now test removeAll: