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<script>
  window.portalHost.postMessage("loaded");

  var ph = window.portalHost;

  window.onportalactivate = e => {
    var exception_name = ""
    try {
      ph.postMessage("message");
    }
    catch (error) {
      exception_name = error.name;
    }
    bc = new BroadcastChannel("portal-host-post-message-after-activate");
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    bc.close();
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</script>