code: public function getValues(ElggEntity $entity) {
  		$files = elgg_get_entities_from_metadata(array(
  			'types' => 'object',
  			'subtypes' => 'file',
  			'container_guids' => (int) $entity->guid,
  			'metadata_name_value_pairs' => array(
  				'name' => 'prototyper_field',
  				'value' => $this->getShortname(),
  			),
  			'limit' => 1,
  		));
  		return ($files) ? $files[0] : false;
  	}
docs: {@inheritdoc}