static int hstackWithSpacing_spacing = 6;

static JPanel hstackWithSpacing(O... parts) {
  JPanel panel = new JPanel(new GridBagLayout);
  new GridBagConstraints gbc;
  gbc.weighty = 1;
  gbc.fill = GridBagConstraints.VERTICAL;
  gbc.gridheight = GridBagConstraints.REMAINDER;
  for i over parts: {
    if (i != 0)
      panel.add(Box.createRigidArea(new Dimension(hstackWithSpacing_spacing, 0)), gbc);
    panel.add(wrapForSmartAdd(parts[i]), gbc);
  }
  gbc.weightx = 1;
  panel.add(Box.createRigidArea(new Dimension(0, 0)), gbc);
  ret panel;
}