static void setFormData(Component form, SS data) {
  if (empty(data)) ret;
  for (Component c : allChildren(form)) {
    S id = componentID(c);
    if (id == null) continue;
    S value = data.get(id);
    if (value == null) continue;
    for (Component c2 : allChildren(c))
      if (c2 instanceof JTextComponent)
        setText((JTextComponent) c2, value);
  }
}