code: @Override
      protected void fireStateChanged() {
          super.fireStateChanged();
  
          Component comp = getSelectedComponent();
          if (comp instanceof AbstractPanel) {
              ((AbstractPanel) comp).tabSelected();
          }
      }
docs: {@inheritDoc}
  <p>
  Overridden to call the method {@code AbstractPanel#tabSelected()} on the currently selected {@code AbstractPanel}, if
  any.
  
  @see AbstractPanel#tabSelected()