ResourceResponse.php

<?php

namespace Drupal\rest;

use Drupal\Core\Cache\CacheableResponseInterface;
use Drupal\Core\Cache\CacheableResponseTrait;
use Symfony\Component\HttpFoundation\Response;

/**
 * Contains data for serialization before sending the response.
 *
 * We do not want to abuse the $content property on the Response class to store
 * our response data. $content implies that the provided data must either be a
 * string or an object with a __toString() method, which is not a requirement
 * for data used here.
 *
 * Routes that return this response must specify the '_format' requirement.
 *
 * @see \Drupal\rest\ModifiedResourceResponse
 */
class ResourceResponse extends Response implements CacheableResponseInterface, ResourceResponseInterface {
    use CacheableResponseTrait;
    use ResourceResponseTrait;
    
    /**
     * Constructor for ResourceResponse objects.
     *
     * @param mixed $data
     *   Response data that should be serialized.
     * @param int $status
     *   The response status code.
     * @param array $headers
     *   An array of response headers.
     */
    public function __construct($data = NULL, $status = 200, $headers = []) {
        $this->responseData = $data;
        parent::__construct('', $status, $headers);
    }

}