public function csv_export($treeNodeParentID = null)
    {
        $me = $this;
        $parent = $me->getParentNode($treeNodeParentID);
        $entity = $me->getEntity($parent);
        $permissions = new \Permissions($entity);
        if (!$permissions->canViewExpressEntries()) {
            throw new \Exception(t('Access Denied'));
        }

        $headers = [
            'Content-Type' => 'text/csv',
            'Content-Disposition' => 'attachment; filename=' . $entity->getHandle() . '.csv',
        ];
        $config = $this->app->make('config');
        $bom = $config->get('concrete.export.csv.include_bom') ? $config->get('concrete.charset_bom') : '';

        return StreamedResponse::create(function () use ($entity, $me, $bom) {
            $entryList = new EntryList($entity);

            $writer = new CsvWriter($this->app->make(WriterFactory::class)->createFromPath('php://output', 'w'), new Date());
            echo $bom;
            $writer->insertHeaders($entity);
            $writer->insertEntryList($entryList);
        }, 200, $headers);
    }