trait SlickFormatterViewTrait in Slick Carousel 8.2

trait SlickFormatterViewTrait {

  /**
   * Returns similar view elements.
   */
  public function commonViewElements(FieldItemListInterface $items, $langcode, array $entities = [], array $settings = []) {

    // Collects specific settings to this formatter.
    $settings = array_merge($this
      ->buildSettings(), $settings);
    $settings['langcode'] = $langcode;

    // Build the settings.
    $build = [
      'settings' => $settings,
    ];

    // Modifies settings before building elements.
    $entities = empty($entities) ? [] : array_values($entities);
    $this->formatter
      ->preBuildElements($build, $items, $entities);

    // Build the elements.
    $elements = $entities ?: $items;
    $this
      ->buildElements($build, $elements, $langcode);

    // Modifies settings post building elements.
    $this->formatter
      ->postBuildElements($build, $items, $entities);

    // Pass to manager for easy updates to all Blazy formatters.
    if (empty($settings['use_theme_field'])) {

      // Return field-vanilla without field markup.
      return $this->manager
        ->build($build);
    }
    else {

      // Return as array to render in regular field.html.twig:
      return [
        $this->manager
          ->build($build),
      ];
    }
  }

}