hen((val) => {
              const elm = document.getElementById('testPromisePolyfilled');
              elm.textContent = val;
              elm.className = 'testPromisePolyfilled';
            });
          })();
        </script>
      </li>

      <li>
        <strong>performance.now()</strong>
        <code>
          <span id="testPerformanceNow"></span>
        </code>
        <script type="text/partytown">
          (function () {
            const elm = document.getElementById('testPerformanceNow')