protected function processIdentifierCollectionRelationship($source, DocumentHydrator $hydrator): IdentifierCollectionRelationship
    {
        $relationship = new IdentifierCollectionRelationship();

        foreach ($source->data as $resourceSrc)
        {
            $relationship->addIdentifier($this->createResourceIdentifier($resourceSrc, $hydrator));
        }

        $hydrator->hydrateObject($relationship, $source);

        return $relationship;
    }