CallsDestructableServiceController.php

<?php

namespace Drupal\destructable_test\Controller;

use Drupal\Core\Controller\ControllerBase;
use Drupal\destructable_test\Destructable;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * Controller to instantiate the destructable service.
 */
final class CallsDestructableServiceController extends ControllerBase {
    
    /**
     * Destructable service.
     *
     * @var \Drupal\destructable_test\Destructable
     */
    protected $destructable;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get(Destructable::class));
    }
    public function __construct(Destructable $destructable) {
        $this->destructable = $destructable;
    }
    
    /**
     * Render callback.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     *   Response.
     */
    public function render(Request $request) : Response {
        $this->destructable
            ->setSemaphore($request->query
            ->get('semaphore'));
        return new Response('This is a longer-ish string of content to send to the client, to invoke any trivial transfer buffers both on the server and client side.');
    }

}