public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('name', null, array('required' => false));
$builder->add('description', null, array('required' => false));
$builder->add('language', null, array('required' => false));
$builder->add('attachment', 'file', array('constraints' => array(new Assert\File(), new Assert\NotNull())));
}