// field: field to use for display
static JComboBox jcomboboxFromConcepts(Class<? extends Concept> cc, S field) {
  ret jcomboboxFromConcepts(mainConcepts, cc, field);
}

static JComboBox jcomboboxFromConcepts(Concepts concepts, Class<? extends Concept> cc, S field) {
  L<S> items = ll("");
  for (Concept c : list(concepts, cc)) {
    S name = "";
    pcall { if (nempty(field)) name = str(cget(c, field)); }
    items.add(c.id + addPrefixIfNotEmpty(" - ", name));
  }
  ret jcombobox(items);
}