protected function addMetadataFieldset(FormInterface $form, RepositoryInterface $repository)
{
$metadata = $form->addChild($this->getElement('nested_fieldset', ['name' => 'metadata', 'label' => $this->trans('common.fieldset.meta')]));
$languageData = $metadata->addChild($this->getElement('language_fieldset', ['name' => 'translations', 'label' => $this->trans('common.fieldset.translations'), 'transformer' => $this->getRepositoryTransformer('translation', $repository)]));
$languageData->addChild($this->getElement('text_field', ['name' => 'meta.title', 'label' => $this->trans('common.label.meta.title')]));
$languageData->addChild($this->getElement('text_field', ['name' => 'meta.keywords', 'label' => $this->trans('common.label.meta.keywords')]));
$languageData->addChild($this->getElement('text_area', ['name' => 'meta.description', 'label' => $this->trans('common.label.meta.description')]));
}