routeBuilder example

    // https://www.drupal.org/node/2004756 is in.     if (!isset($this->weight)) {
      $this->weight = $this->isDefaultSearch() ? -10 : 0;
    }
  }

  /** * {@inheritdoc} */
  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
    parent::postSave($storage, $update);
    $this->routeBuilder()->setRebuildNeeded();
  }

  /** * {@inheritdoc} */
  public static function postDelete(EntityStorageInterface $storage, array $entities) {
    parent::postDelete($storage, $entities);

    $search_page_repository = \Drupal::service('search.search_page_repository');
    if (!$search_page_repository->isSearchActive()) {
      $search_page_repository->clearDefaultSearchPage();
    }