splitPane.setOpaque(true);
  protected void installDefaults()  {    divider = createDefaultDivider();    resetLayoutManager();    nonContinuousLayoutDivider = createDefaultNonContinuousLayoutDivider();    splitPane.add(divider, JSplitPane.DIVIDER);    // There is no need to add the nonContinuousLayoutDivider    UIDefaults defaults = UIManager.getLookAndFeelDefaults();    splitPane.setBackground(defaults.getColor("SplitPane.background"));    splitPane.setBorder(defaults.getBorder("SplitPane.border"));    splitPane.setDividerSize(defaults.getInt("SplitPane.dividerSize"));  }