static <A> JComboBox<A> selectItem(A item, JComboBox<A> cb) {
  if (cb != null) swing { cb.setSelectedItem(item); }
  ret cb;
}

static <A> JComboBox<A> selectItem(JComboBox<A> cb, A item) {
  ret selectItem(item, cb);
}

static <A> JList<A> selectItem(JList<A> list, A item) {
  swing { selectRow(list, jlist_indexOf(list, item)); }
  ret list;
}