/** Delegate {@link SelectionNotifier} calls to the container. */
 @Override
 public void setSelectionListeners(Set<SelectionListener> listeners) {
   m_container.setSelectionListeners(listeners);
   for (SelectionNotifier notifier : m_selectionNotifiers) {
     notifier.setSelectionListeners(listeners);
   }
 }
 /** Delegate {@link SelectionNotifier} calls to the container. */
 @Override
 public void removeSelectionListener(SelectionListener listener) {
   m_container.removeSelectionListener(listener);
   for (SelectionNotifier notifier : m_selectionNotifiers) {
     notifier.removeSelectionListener(listener);
   }
 }
 /** Delegate {@link SelectionNotifier} calls to the container. */
 @Override
 public void addSelectionListener(SelectionListener listener) {
   if (listener != null) {
     m_container.addSelectionListener(listener);
     for (SelectionNotifier notifier : m_selectionNotifiers) {
       notifier.addSelectionListener(listener);
     }
   }
 }
 @Override
 public void selectionChanged(SelectionContext selectionManager) {
   m_container.selectionChanged(selectionManager);
 }