QueryCommand query,
Map<SelectorName, Table> usedSelectors ) {
// // Resolve everything ...
// Visitors.visitAll(query, new Validator(context, usedSelectors));
// Resolve everything (except subqueries) ...
Validator validator = new Validator(context, usedSelectors);
query.accept(new WalkAllVisitor(validator) {
@Override
protected void enqueue( Visitable objectToBeVisited ) {
if (objectToBeVisited instanceof Subquery) return;
super.enqueue(objectToBeVisited);