<script>
document.addEventListener('DOMContentLoaded', () => {
  let a = document.documentElement
  SpecialPowers.wrap(self).printPreview().document.adoptNode(a)
  let b = document.createElementNS('http://www.w3.org/1999/xhtml', 'optgroup')
  a.appendChild(b)
  b.focus({ })
})
</script>
