Drupal8在控制器中渲染一个块？

namespace Drupal\my_module\Controller;

use Drupal\Core\Controller\ControllerBase;

class CustomController extends ControllerBase {

  public function renderBlock() {
    $block = \Drupal::service('plugin.manager.block')->createInstance('my_custom_block_id');
    $render_array = \Drupal::entityTypeManager()
      ->getViewBuilder('block')
      ->view($block);
    return $render_array;
  }

}

<div class="custom-block">
  {{ content }}
</div>

my_module.custom_controller_render_block:
  path: '/custom-controller/render-block'
  defaults:
    _controller: '\Drupal\my_module\Controller\CustomController::renderBlock'
    _title: 'Render Block'
  requirements:
    _permission: 'access content'