public static function createDemoContent($pluginId, array &$context) {
    // Reset time limit so we don't timeout.
    drupal_set_time_limit(0);

    // Needs to be resolved manually since we don't have a context.
    /** @var \Drupal\presto\Installer\DemoContentManager $demoContentManager */
    $demoContentManager = Drupal::service(
      'plugin.manager.presto.demo_content'
    );

    $definition = $demoContentManager->getDefinition($pluginId);
    /** @var \Drupal\Core\StringTranslation\TranslatableMarkup $label */
    $label = $definition['label'];

    /** @var \Drupal\presto\Plugin\Presto\DemoContent\AbstractDemoContent $instance */
    $instance = $demoContentManager->createInstance($pluginId);
    $instance->createContent();

    $context['results'][] = $pluginId;
    $context['message'] = t('Running %task_name', [
      '%task_name' => lcfirst($label->render()),
    ]);
  }