     document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) =&gt; {
        img.addEventListener(&quot;load&quot;, resolve, {once: true});
      });
      img.src = testURI(&quot;resource&quot;, &quot;image&quot;, key);
      await imgLoadPromise;
      let response = await fetch(
        testURI(&quot;ctr&quot;, &quot;image&quot;, key), {&quot;cache&quot;: &quot;reload&quot;});
      return (await response.text()).trim();
    }

result, same first party: 1

result, differe