static JButton renameButton(JComponent c, S name) {
  JButton b = first(childrenOfType(c, JButton.class));
  if (b != null)
    b.setText(name);
  ret b;
}

static JButton renameButton(JComponent c, S oldName, S newName) {
  JButton b = findButton(c, oldName);
  if (b != null) b.setText(newName);
  ret b;
}