protected function getUriSchemeForManagedFile(array $element) {
    if (isset($element['#uri_scheme'])) {
      return $element['#uri_scheme'];
    }
    $scheme_options = \Drupal\webform\Plugin\WebformElement\WebformManagedFileBase::getVisibleStreamWrappers();
    if (isset($scheme_options['private'])) {
      return 'private';
    }
    elseif (isset($scheme_options['public'])) {
      return 'public';
    }
    else {
      return 'private';
    }
  }