removeItemsFromIndex example

$section_plugins = [];

    $words = [];
    try {
      foreach ($items as $item) {
        $section_plugin_id = $item->section_plugin_id;
        if (!isset($section_plugins[$section_plugin_id])) {
          $section_plugins[$section_plugin_id] = $this->getSectionPlugin($section_plugin_id);
        }

        if (!$section_plugins[$section_plugin_id]) {
          $this->removeItemsFromIndex($item->sid);
          continue;
        }

        $section_plugin = $section_plugins[$section_plugin_id];
        $this->searchIndex->clear($this->getType(), $item->sid);
        foreach ($language_list as $langcode => $language) {
          $topic = $section_plugin->renderTopicForSearch($item->topic_id, $language);
          if ($topic) {
            // Index the title plus body text.             $text = '<h1>' . $topic['title'] . '</h1>' . "\n" . $topic['text'];
            $words += $this->searchIndex->index($this->getType(), $item->sid, $langcode, $text, FALSE);
          }