protected function add_additional_fields_to_object( $object, $request ) {

		$additional_fields = $this->get_additional_fields();

		foreach ( $additional_fields as $field_name => $field_options ) {

			if ( ! $field_options['get_callback'] ) {
				continue;
			}

			$object[ $field_name ] = call_user_func( $field_options['get_callback'], $object, $field_name, $request, $this->get_object_type() );
		}

		return $object;
	}