/**
  * {@inheritdoc}
  */
 public function buildForm(FormBuilderInterface $builder, array $options)
 {
     $builder->addEventSubscriber(new CollectionUploadSubscriber($builder->getName(), $options, $this->storage));
     if (!$builder->hasAttribute('prototype')) {
         $prototype = $builder->create($options['prototype_name'], $options['type'], array_replace(array('label' => $options['prototype_name'] . 'label__'), $options['options']));
         $builder->setAttribute('prototype', $prototype->getForm());
     }
 }