 = "data-url-shared-worker";
    const worker_1_name = `${worker_name_prefix}-1`;
    const worker_2_name = `${worker_name_prefix}-2`;

    const handler = e => {
      if(e.data == `${worker_1_name}-done`) {
        const worker_script = data_url_worker_src(channel_name, worker_2_name);
        const worker2 = new SharedWorker(worker_script, worker_2_name);
        worker2.port.addEventListener("message", handler);
        worker2.port.start();
        worker2.port.postMessage("go!");
      } else if(e.dat