static <B, A extends JComboBox<B>> A bindComboBoxToVar(IVarWithNotify<B> var, A cb) {
  if (var != null) {
    bindListenerToComponent(cb, var, (Runnable) () -> selectItem(cb, var!));
    onChange(cb, (Runnable) () -> var.set(getSelected(cb));
  }
  ret cb;
}

static <B, A extends JComboBox<B>> A bindComboBoxToVar(A cb, IVarWithNotify<B> var) {
  ret bindComboBoxToVar(var, cb);
}