->add('parent', EntityType::class, [
            'label'         =>  $translator->trans('entity.parent'),
            'required'      =>  false,
            'class'         =>  'AppBundle:Category',
            'choice_label'  =>  'title',
            'placeholder'   =>  $translator->trans('entity.no_parent'),
            'attr'          =>  ['class' => 'form-control']
        ])