id="hostDelegatesFocus"></div>
<div id="hostNonDelegatesFocus"></div>
<div contenteditable="true"></div>
<div id="scrollable"><div id="scrollable-inner"></div></div>
<fieldset></fieldset>
<output></output>
<slot></slot>
<script>
document.getElementById("hostDelegatesFocus").attachShadow({ mode: "open", delegatesFocus: true });
document.getElementById("hostNonDelegatesFocus").attachShadow({ mode: "open", delegatesFocus: false });
const defaultList = [
  ["input", 0],
  ["input[type='hidden']", 0],
  ["button