outline-8.x-1.x-dev/tests/modules/outline_serialization_test/src/OutlineSerializationTestController.php

<?php

namespace Drupal\outline_serialization_test;

use Drupal\outline\OutlineInterface;

class OutlineSerializationTestController {

  public function outlineResponse(OutlineInterface $outline) {
    $response = new OutlineResponse('this is the output');
    $response->setOutline($outline);
    return $response;
  }

}