code: protected function voteOnAttribute($attribute, $subject, TokenInterface $token): bool
      {
          $user = $token->getUser();
          [, $field] = explode('.', $attribute, 2);
  
          if (!$user instanceof BackendUser || (!is_scalar($subject) && !\is_array($subject))) {
              return false;
          }
  
          return $user->hasAccess($subject, $field);
      }
docs: {@inheritdoc}