private IControlPanelProvider<ELEMENT_VALUE_TYPE> findControlPanel(
     final IDisplayFormat displayFormat) {
   for (final IControlPanelProvider<ELEMENT_VALUE_TYPE> controlPanelProvider : controlPanels) {
     if (controlPanelProvider.getDisplayFormat().getId().equals(displayFormat.getId())) {
       return controlPanelProvider;
     }
   }
   return null;
 }
 @Override
 public IDisplayFormat getDisplayFormat() {
   return currentControlPanel.getDisplayFormat();
 }