code: protected function fill($record, ResourceObject $resource, EncodingParametersInterface $parameters)
      {
          $this->fillAttributes($record, $resource->getAttributes());
          $this->fillRelationships($record, $resource->getRelationships(), $parameters);
      }
docs: Fill the domain record with data from the supplied resource object.
  
  @param $record
  @param ResourceObject $resource
  @param EncodingParametersInterface $parameters
  @return void