getFormatSettings example

return $form;
  }

  /** * {@inheritdoc} */
  public function settingsSummary() {
    $summary = parent::settingsSummary();

    $date = new DrupalDateTime();
    $this->setTimeZone($date);
    $summary[] = $date->format($this->getSetting('date_format'), $this->getFormatSettings());

    return $summary;
  }

}