public void init(ICommonActionExtensionSite actionExtensionSite) {
   super.init(actionExtensionSite);
   this.actionExtensionSite = actionExtensionSite;
   ICommonViewerSite site = actionExtensionSite.getViewSite();
   if (site instanceof ICommonViewerWorkbenchSite) {
     action.setViewer(actionExtensionSite.getStructuredViewer());
     action.setSelection(actionExtensionSite.getStructuredViewer().getSelection());
     actionExtensionSite.getStructuredViewer().addSelectionChangedListener(action);
   }
 }