code: public function process(ContainerBuilder $container)
      {
          $serviceId = 'simple_bus.asynchronous.publishes_predefined_messages_middleware';
          if (!$container->hasDefinition($serviceId)) {
              return;
          }
  
          $names = array();
          $this->collectServiceIds(
              $container,
              'asynchronous_event_subscriber',
              'subscribes_to',
              function ($key) use (&$names) {
                  $names[] = $key;
              }
          );
  
          $container->getDefinition($serviceId)->replaceArgument(2, array_unique($names));
      }
docs: Get all asynchronous event subscribers and save the name of the event they are listening to.
  
  @param ContainerBuilder $container