Support placing the navbar into the top navigation

SearchBlockForm.php

<?php
namespace Drupal\bootstrap_mobildata\Plugin\Form;

use Drupal\bootstrap\Annotation\BootstrapForm;
use Drupal\bootstrap\Utility\Element;
use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * @BootstrapForm("search_block_form")
 */
class SearchBlockForm extends \Drupal\bootstrap\Plugin\Form\SearchBlockForm {

  /**
   * {@inheritdoc}
   */
  public function alterFormElement(Element $form, FormStateInterface $form_state, $form_id = NULL) {
    parent::alterFormElement($form, $form_state, $form_id);
    $form->addClass(['navbar-form', 'navbar-right']);
  }

}