Auth.php

<?php

namespace Drupal\early_translation_test;

use Drupal\Core\Authentication\AuthenticationProviderInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Symfony\Component\HttpFoundation\Request;

/**
 * Test authentication provider.
 */
class Auth implements AuthenticationProviderInterface {
    
    /**
     * The user storage.
     *
     * @var \Drupal\user\UserStorageInterface
     */
    protected $userStorage;
    
    /**
     * Constructs an authentication provider object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager) {
        // Authentication providers are called early during in the bootstrap.
        // Getting the user storage used to result in a circular reference since
        // translation involves a call to \Drupal\locale\LocaleLookup that tries to
        // get the user roles.
        // @see https://www.drupal.org/node/2241461
        $this->userStorage = $entity_type_manager->getStorage('user');
    }
    
    /**
     * {@inheritdoc}
     */
    public function applies(Request $request) {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function authenticate(Request $request) {
        return NULL;
    }

}