How to check if user has Role in Drupal 8

Code snippet that can be used to check if user has Role in Drupal 8.

<?php

namespace Drupal\mymodule;

use Drupal\Core\Session\AccountInterface;

/**
 * Class CustomService
 * @package Drupal\mymodule\Services
 */
class CustomService
{

  protected $currentUser;

  /**
   * CustomService constructor.
   * @param AccountInterface $currentUser
   */
  public function __construct(AccountInterface $currentUser)
  {
    $this->currentUser = $currentUser;
  }


  /**
   * @return bool
   */
  public function isAdministrator()
  {
    $user_roles = $this->currentUser->getRoles();
    if (in_array('administrator', $user_roles)) {
      return true;
    }
    return false;
  }

}