// remove from tree model
clickedNode.removeFromParent();
qtiPackage.serializeQTIDocument();
menuTree.setSelectedNodeId(clickedNode.getParent().getIdent());
event(ureq, menuTree, new Event(MenuTree.COMMAND_TREENODE_CLICKED));
//ask user to confirm referenced media removal
if(deletableMediaFiles!=null && deletableMediaFiles.size()>0) {
String msg = translate("delete.item.media", deletableMediaFiles.toString());
deleteMediaDialog = activateYesNoDialog(ureq, null, msg, deleteMediaDialog);
}