List roles;
SelectQuery select_role = new SelectQuery(Role.class);
roles = Context.getContext().performQuery(select_role);
Calendar c = new GregorianCalendar();
c.set(c.get(Calendar.YEAR) - 100, 0, 1, 0, 0, 0);
Expression qualifier3 = Expression.fromString("artist.dateOfBirth < $date");
qualifier3 = qualifier3.expWithParameters(Collections.singletonMap("date", c.getTime()));
SelectQuery select3 = new SelectQuery(Painting.class, qualifier3);
List paintings3 = context.performQuery(select3);