@Override
public Boolean walkNotIn(Tree opNode, Tree colNode, Tree listNode) {
// Note just return !walkIn(node, colNode, listNode) is wrong,
// because
// then it evaluates to true for null values (not set properties).
ColumnReference colRef = getColumnReference(colNode);
PropertyDefinition<?> pd = colRef.getPropertyDefinition();
PropertyData<?> lVal = so.getProperties().get(colRef.getPropertyId());
List<Object> literals = onLiteralList(listNode);
if (pd.getCardinality() != Cardinality.SINGLE) {
throw new IllegalStateException("Operator IN only is allowed on single-value properties ");
} else if (lVal == null) {
return false;