code: function compareKey(one, two) {
    const delta = one.length - two.length;
    if (delta > 0) {
      return 1;
    }
    if (delta < 0) {
      return -1;
    }
    return one > two ? 1 : -1;
  }
docs: Helper function to compare route keys (e.g. "9", "11").