<!doctype html>
<script>
const baseLocation = window.location;
const workerUrl = new URL('create-blob-url-worker.js', baseLocation).href;
const worker = new Worker(workerUrl);

function fetch_in_worker(url) {
  const resourceUrl = new URL(url, baseLocation).href;
  return new Promise((resolve) => {
    worker.onmessage = (event) => {
      resolve(event.data);
    };
    worker.postMessage(resourceUrl);
  });
}
</script>