protected function indexStep($step) {
    $text = '<h1>' . $step->title . '</h1> ';
    $text .= $step->description . ' ';

    $text = trim($text);

    // Use the current default interface language.
    $language =  \Drupal::languageManager()->getCurrentLanguage();

    // Instantiate the transliteration class.
    $transliteration = \Drupal::service('transliteration');

    // Use this to transliterate some text.
    $text_transliterate .= $transliteration->transliterate($text, $language->getId());
    $text = $text . $text_transliterate . ' ';

    // Fetch extra data normally not visible.
    $extra = \Drupal::moduleHandler()->invokeAll('step_update_index', [$step]);
    foreach ($extra as $t) {
      $text .= $t;
    }

    // Update index, using search index "type" equal to the plugin ID.
    search_index($this->getPluginId(), $step->course_esid, $language->getId(), $text);
  }