src/vs/workbench/contrib/bulkEdit/browser/preview/bulkEditTree.ts/BulkEditNaviLabelProvider/getKeyboardNavigationLabel
class BulkEditNaviLabelProvider:	getKeyboardNavigationLabel(element: BulkEditElement) {
		if (element instanceof FileElement) {
			return basename(element.edit.uri);
		} else if (element instanceof CategoryElement) {
			return element.category.metadata.label;
		}
		return undefined;
	}