static JPanel withRightAlignedButtons_marginAttachedToCenter(JComponent center, O... params) {
  ret centerAndSouth(withMargin(center), jRightAlignedButtons(params));
}

static JPanel withRightAlignedButtons_marginAttachedToCenter(Swingable center, O... params) {
  ret withRightAlignedButtons_marginAttachedToCenter(wrap(center), params);
}