rem: return this.tree.selectedItems; 
add:    return [].concat(this.tree.selectedItems); 
context:   getSelection: function ()  {    return this.tree.selectedItems;  },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/9de468a21823f4a20c760c16bb7cd5324cee136a/bookmarksTree.js/buggy/xpfe/components/bookmarks/resources/bookmarksTree.js