static int vstackWithSpacing_fixed_default = 10;

static JPanel vstackWithSpacing_fixed(L parts, int spacing default vstackWithSpacing_fixed_default) {
  ret swing(-> {
    JPanel panel = new JPanel(new GridBagLayout);
    new GridBagConstraints gbc;
    gbc.weightx = 1;
    gbc.fill = GridBagConstraints.HORIZONTAL;
    gbc.gridwidth = GridBagConstraints.REMAINDER;
    gbc.insets = new Insets(0, 0, spacing, 0);
    smartAddWithLayout(panel, gbc, flattenToArray(parts));
    gbc.weighty = 1;
    gbc.insets = new Insets(0, 0, 0, 0);
    panel.add(jrigid(), gbc);
    ret panel;
  });
}

static JPanel vstackWithSpacing_fixed(int spacing default vstackWithSpacing_fixed_default, Component... parts) {
  ret vstackWithSpacing_fixed(asList(parts), spacing);
}

Began life as a copy of #1006626