public static JLabel setupExtension(@NotNull EditorEx editor,
                                     Color background,
                                     ExtendableTextComponent.Extension extension) {
    JLabel label = ExpandableSupport.createLabel(extension);
    label.setBorder(JBUI.Borders.emptyLeft(2));
    editor.getScrollPane().setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
    editor.getScrollPane().setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
    JScrollBar scrollBar = editor.getScrollPane().getVerticalScrollBar();
    JPanel panel = ClientProperty.get(scrollBar, BUTTON_CONTAINER);
    if (panel == null) {
      panel = new JPanel(new HorizontalLayout(4));
      panel.setOpaque(false);
      ClientProperty.put(scrollBar, BUTTON_CONTAINER, panel);
      scrollBar.setBackground(background);
      scrollBar.add(JBScrollBar.LEADING, panel);
      scrollBar.setOpaque(true);
    }
    panel.add(label);

    return label;
  }
public static JLabel setupExtension(@NotNull EditorEx editor,
                                     Color background,
                                     ExtendableTextComponent.Extension extension)