async () =&gt; {
      let cache = await caches.open(&quot;supercookies&quot;);
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get(&quot;key&quot;);
    }

result, same first party: ae3a5c11-9564-4c12-8aa3-be101efafcac

result, different first party: ae3a5c11-9564-4c12-8aa3-be101efafcac

unsupported: false

passed: false

test failed: false</span>
</div></td></tr><tr><td><div class="tooltipParent">cookie (HTTP)<span class="tooltipText">Th