static JComboBox jcomboboxFromConcepts_str(Class<? extends Concept> cc) {
  ret jcomboboxFromConcepts_str(mainConcepts, cc);
}

static JComboBox jcomboboxFromConcepts_str(Concepts concepts, Class<? extends Concept> cc) {
  L<S> items = ll("");
  for (Concept c : list(concepts, cc))
    items.add(c.id + " - " + c));
  ret jcombobox(items);
}