src/Client/ClientSerializer.php
public function serializeRelated($related, $meta = null, array $links = [])
    {
        $serializer = clone $this->serializer;
        $serializer->withMeta($meta)->withLinks($links);

        return $serializer->serializeIdentifiers($related);
    }
public function serializeRelated($related, $meta = null, array $links = [])
    {
        $serializer = clone $this->serializer;
        $serializer->withMeta($meta)->withLinks($links);

        return $serializer->serializeIdentifiers($related);
    }
Serialize related record(s).

@param object|iterable|array|null $related
@param mixed|null $meta
@param array $links
@return array