code: function showNotification(data) {
    if (!data || !data.tag) {
      // eslint-disable-next-line no-param-reassign
      data = $Notifications.default;
    }
    logger.group(data.tag);
    logger.log('Show notification.', data.tag);
    return self.registration
      .showNotification(data.title, data)
      .then(delayDismissNotification);
  }
docs: /*         -------- NOTIFICATIONS HELPERS ---------