class ParagraphsServiceProvider

class ParagraphsServiceProvider extends ServiceProviderBase {

  /**
   * {@inheritdoc}
   */
  public function register(ContainerBuilder $container) {
    $modules = $container
      ->getParameter('container.modules');

    // Check for installed Replicate module.
    if (isset($modules['replicate'])) {

      // Add a Replicate field event subscriber.
      $service_definition = new Definition('Drupal\\paragraphs\\EventSubscriber\\ReplicateFieldSubscriber', [
        new Reference('replicate.replicator'),
      ]);
      $service_definition
        ->addTag('event_subscriber');
      $service_definition
        ->setPublic(TRUE);
      $container
        ->setDefinition('replicate.event_subscriber.paragraphs', $service_definition);
    }

    // Check for installed Migrate module.
    if (isset($modules['migrate'])) {

      // Add a Migration plugins alterer service.
      $service_definition = new Definition('Drupal\\paragraphs\\MigrationPluginsAlterer');
      $service_definition
        ->addArgument(new Reference('logger.factory'));
      $service_definition
        ->setPublic(TRUE);
      $container
        ->setDefinition('paragraphs.migration_plugins_alterer', $service_definition);
    }
  }

}