public PanelAP ensureFooter() {
   if (footer == null) {
     footer = Core.CF.panelAppearance();
     footer.setStyleName("panel-footer");
     main.add(footer);
   }
   return footer;
 }
 @Override
 public PanelAP ensureFooter() {
   if (footer == null) {
     footer = Core.CF.panelAppearance();
     footer.addStyleName(Core.coreCss.pageFormFooter());
     main.add(footer);
   }
   return footer;
 }