website/static/playground.js/replaceHash
function replaceHash(hash) {
  if (
    typeof URL === "function" &&
    typeof history === "object" &&
    typeof history.replaceState === "function"
  ) {
    var url = new URL(location);
    url.hash = hash;
    history.replaceState(null, null, url);
  } else {
    location.hash = hash;
  }
}