public static SubSelect qualify(ISession session, SubSelect subSelect) {
String alias = subSelect.getAlias();
SelectBody select = subSelect.getSelectBody();
SelectQualifier visitor = new SelectQualifier(session);
select.accept(visitor);
PlainSelect qualifiedSelect = visitor.getQualifiedQuery();
SubSelect qualifiedSubSelect = new SubSelect();
qualifiedSubSelect.setAlias(alias);