/**
  * {@inheritdoc}
  */
 public function apply(DatasourceInterface $datasource, $field, $direction)
 {
     $attribute = $this->attributeRepository->findOneByCode($field);
     $qb = $datasource->getQueryBuilder();
     $pqb = $this->productRepository->getProductQueryBuilder($qb);
     $pqb->addAttributeSorter($attribute, $direction);
 }
 /**
  * Returns the Attribute
  *
  * @param string $code
  *
  * @return AbstractAttribute
  */
 protected function getAttributeByCode($code)
 {
     return $this->attributeRepository->findOneByCode($code);
 }