code: private void defineRootPanes(UIDefaults d) {
          String c = PAINTER_PREFIX + "FrameAndRootPainter";
          String p = "RootPane";
  
          d.put(p + ".States", "Enabled,WindowFocused,NoFrame");
          d.put(p + ".contentMargins", new InsetsUIResource(0, 0, 0, 0));
          d.put(p + ".opaque", Boolean.FALSE);
          d.put(p + ".NoFrame", new RootPaneNoFrameState());
          d.put(p + ".WindowFocused", new RootPaneWindowFocusedState());
  
          d.put(p + "[Enabled+NoFrame].backgroundPainter", new LazyPainter(c, FrameAndRootPainter.Which.BACKGROUND_ENABLED_NOFRAME));
          d.put(p + "[Enabled].backgroundPainter", new LazyPainter(c, FrameAndRootPainter.Which.BACKGROUND_ENABLED));
          d.put(p + "[Enabled+WindowFocused].backgroundPainter", new LazyPainter(c, FrameAndRootPainter.Which.BACKGROUND_ENABLED_WINDOWFOCUSED));
      }
docs: Initialize the root pane settings.
  
  @param d the UI defaults map.