/**
  * Retrieves a collection of resources.
  *
  * @param Request $request The request
  * @param int $id The ID of the part
  *
  * @return array|\Dunglas\ApiBundle\Model\PaginatorInterface|\Traversable
  *
  * @throws RuntimeException
  */
 public function __invoke(Request $request, $id)
 {
     list($resourceType) = $this->extractAttributes($request);
     /**
      * @var PartMeasurementUnit $partMeasurementUnit
      */
     $partMeasurementUnit = $this->getItem($this->dataProvider, $resourceType, $id);
     $this->partMeasurementUnitService->setDefault($partMeasurementUnit);
     return $partMeasurementUnit;
 }