docs: public static Collection<Subquery> subqueries( Visitable visitable,
                                                     final boolean includeNestedSubqueries ) {
          final Collection<Subquery> subqueries = new LinkedList<Subquery>();
          Visitors.visitAll(visitable, new Visitors.AbstractVisitor() {
              @Override
              public void visit( Subquery subquery ) {
                  subqueries.add(subquery);
                  if (includeNestedSubqueries) {
                      // Now look for any subqueries in the subquery ...
                      subquery.getQuery().accept(this);
                  }
              }
          });
          return subqueries;
      }