Sylius\Bundle\ProductBundle\Form\Type\ProductGenerateVariantsType::buildForm PHP Метод

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('variants', CollectionType::class, ['entry_type' => ProductVariantGenerationType::class, 'allow_add' => true, 'allow_delete' => true, 'by_reference' => false])->addEventSubscriber($this->generateProductVariantsSubscriber);
    }