code: protected function fillRelationship(
          $record,
          $field,
          array $relationship,
          EncodingParametersInterface $parameters
      ) {
          $relation = $this->getRelated($field);
  
          $relation->update($record, $relationship, $parameters);
      }
docs: Fill a relationship from a resource object.
  
  @param $record
  @param $field
  @param array $relationship
  @param EncodingParametersInterface $parameters