private void installPainter(@NotNull JRootPane rootPane) {
        Component glassPane = rootPane.getGlassPane();
        if (glassPane instanceof IdeGlassPane) {
            assert disposable == null : "Disposable is not null";
            disposable = Disposer.newDisposable("Ruler Guide");
            Disposer.register(this, disposable);
            ((IdeGlassPane) glassPane).addPainter(glassPane, this, disposable);
        } else {
            ThiefGlassPane glass = new ThiefGlassPane(glassPane);
            rootPane.setGlassPane(glass);
            glass.setVisible(true);
            glass.revalidate();
        }
    }
private void installPainter(@NotNull JRootPane rootPane)