public function buildForm(FormBuilder $builder, array $options)
 {
     parent::buildForm($builder, $options);
     $builder->setAttribute('theme', $options['theme']);
 }
 /**
  * {@inheritdoc}
  */
 public function buildView(FormView $view, FormInterface $form, array $options)
 {
     parent::buildView($view, $form, $options);
     $view->vars['attr']['class'] = trim(@$view->vars['attr']['class'] . ' rich-field');
 }