public function index()
    {
        $form = $this->bulkEditForm();
        $form->setTemplate([
            'type' => 'Includes',
            'SilverStripe\\Admin\\LeftAndMain_EditForm',
        ]);
        $form->addExtraClass('center cms-content');
        $form->setAttribute('data-pjax-fragment', 'CurrentForm Content');

        Requirements::javascript('colymba/gridfield-bulk-editing-tools:client/dist/js/main.js');
        Requirements::css('colymba/gridfield-bulk-editing-tools:client/dist/styles/main.css');
        Requirements::add_i18n_javascript('colymba/gridfield-bulk-editing-tools:lang');

        if ($this->request->isAjax()) {
            $response = new HTTPResponse(
                Convert::raw2json(array('Content' => $form->forAjaxTemplate()->getValue()))
            );
            $response->addHeader('X-Pjax', 'Content');
            $response->addHeader('Content-Type', 'text/json');
            $response->addHeader('X-Title', 'SilverStripe - Bulk ' . $this->gridField->list->dataClass . ' Editing');

            return $response;
        } else {
            $controller = $this->getToplevelController();

            return $controller->customise(array('Content' => $form));
        }
    }