@Path("process/{id}")
  @Produces(SseFeature.SERVER_SENT_EVENTS)
  @GET
  public EventOutput getProgress(
      @PathParam("id") int id,
      @DefaultValue("false") @QueryParam("testSource") boolean testSource) {
    final Process process = processes.get(id);

    if (process != null) {
      if (testSource) {
        process.release();
      }
      final EventOutput eventOutput = new EventOutput();
      process.getBroadcaster().add(eventOutput);
      return eventOutput;
    } else {
      throw new NotFoundException();
    }
  }