sclass UIURLSystem(SimpleLiveValue<S> uiURL) {
  settable SingleComponentPanel scp;
  
  JComponent urlBar() {
    ret withMargin(withLabel("Show",
      comboBoxAndButton(
        onSelectedItem(
          bindComboBoxToLiveValue(centerComboBox(autoComboBox(uiURL, cloneKeys(uiMap))), uiURL),
          url -> showUIURL(url)
        ),
        "Go", url -> showUIURL(url))));
  }
  
  void go {
    showUIURL(
  }
}