protected void addCustomPanel(JPanel customPanel){
  if (customPanelList == null) {
    customPanelList=new ArrayList<Component>();
  }
  customPanelList.add(customPanel);
}

protected void addCustomPanel ( JPanel customPanel ) { if ( customPanelList == null ) { customPanelList = new ArrayList < Component > ( ) ; } customPanelList . add ( customPanel ) ; }
adds the custom panel to the list of custom panels .
