<html>
<head>
<script>
window.addEventListener('load', async () => {
  const frame = document.createElement('frame')
  document.documentElement.appendChild(frame)
  const peer = new RTCPeerConnection()
  await peer.setRemoteDescription({}, () => {}, async () => await peer.getIdentityAssertion())
  peer.close()
})
</script>
</head>
</html>

