// Get the list of property and reference expressions that are used in the Ordering instances, using a visitor. Other
// kinds of
// dynamic operands in Ordering instances will not need to change the columns
final Set<Column> sortColumns = new HashSet<Column>();
Visitor columnVisitor = new Visitors.AbstractVisitor() {
@Override
public void visit( PropertyValue prop ) {
sortColumns.add(columnFor(prop.selectorName(), prop.getPropertyName(), includeSourceName));
}