<html><body>
<iframe id="frame" sandbox="allow-scripts allow-popups"></iframe>
<script type="application/javascript">
/* eslint-disable no-useless-concat */
onmessage = function(e) {
parent.postMessage(e.data, '*');
}
var ifr = document.getElementById('frame');
if (location.search == '?nested') {
let url = new URL(location);
url.search = "";
ifr.src = url.href;
} else if (location.search == '?popup') {
let url = new URL(location);
url.search = "?opener";
ifr.srcdoc = "
