static int vstackWithSpacing_default = 10;

static JPanel vstackWithSpacing(fL parts) {
  ret vstackWithSpacing(parts, vstackWithSpacing_default);
}

static JPanel vstackWithSpacing(fL parts, final int spacing) {
  ret swing(func -> JPanel {
    JPanel panel = new JPanel(new GridBagLayout);
    new GridBagConstraints gbc;
    gbc.weightx = 1;
    gbc.fill = GridBagConstraints.HORIZONTAL;
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.insets = new Insets(spacing/2, 0, (spacing+1)/2, 0); // well...
    smartAddWithLayout(panel, gbc, toObjectArray(nonNulls(parts)));
    //gbc = (GridBagConstraints) gbc.clone();
    //gbc.fill = GridBagConstraints.BOTH;
    gbc.weighty = 1;
    gbc.insets = new Insets(0, 0, 0, 0);
    panel.add(jrigid(), gbc);
    ret panel;
  });
}

static JPanel vstackWithSpacing(Component... parts) {
  ret vstackWithSpacing(asList(parts), vstackWithSpacing_default);
}

static JPanel vstackWithSpacing(int spacing, Component... parts) {
  ret vstackWithSpacing(asList(parts), spacing);
}

Began life as a copy of #1006475