<script>
var timeout = async function (cmd) {
  const timer = new Promise((resolve, reject) => {
    const id = setTimeout(() => {
      clearTimeout(id)
      reject(new Error('Promise timed out!'))
    }, 750)
  })
  return Promise.race([cmd, timer])
}
window.addEventListener('load', async () => {
  let a = new RTCPeerConnection({
    'iceServers': [{'urls': 'stun:23.21.150.121'}],
    'peerIdentity': 'x',
  })
  let b = await timeout(a.createOffer({ }))
  a.setLocalDescription(b)
  try { a.setRemoteDescription(b) } catch (e) {}
  a.setLocalDescription(b)
})
</script>

