$form['advanced'] = array(
 '#type' => 'details',
 '#title' => t('Advanced settings'),
 '#description' => t('Lorem ipsum.'),
 '#open' => TRUE, // Controls the HTML5 'open' attribute.

 $role_object = Role::load('authenticated');
 if ($role_object) {
   $role_object->grantPermission('mymodule write messages');
   $role_object->save();
 }

use Drupal\field\Entity\FieldStorageConfig;
use Drupal\field\Entity\FieldConfig;

/**
* Implements hook_uninstall().
*/
function 

.slick-list {
  margin: 0 -24px;
}

.slick__slide {
  margin: 0 24px;
}

Theme file:

<?php
namespace Drupal\mymodule\Plugin\Block;
use Drupal\Core\Block\BlockBase;
use Drupal\Co

use Drupal\Core\Routing\RouteMatchInterface;

/**
 * The current route match.
 *
 * @var \Drupal\Core\Routing\RouteMatchInterface
 */
protected $routeMatch;

/**
 * Constructs a PrivatemsgMessageForm object.
 *
 * @param \Drupal\Core\En

use Drupal\Core\Logger\LoggerChannelFactoryInterface;

/**
 * Logger Factory.
 *
 * @var \Drupal\Core\Logger\LoggerChannelFactoryInterface
 */
protected $logger;

/**
 * Constructor.
 */
public 

$roles = $this->entityTypeManager->getStorage('user_role')->loadMultiple();

\Drupal::entityTypeManager()
 ->getStorage('entity_view_display')
 ->load('user.user.default')
 ->setComponent('field_notify', [
   'region' => 'hidden',
 ])->save();