shiftToAll() {
    if (!this.isValid) return this;
    return this.shiftTo(
      "years",
      "months",
      "weeks",
      "days",
      "hours",
      "minutes",
      "seconds",
      "milliseconds"
    );
  }
Shift this Duration to all available units.
Same as shiftTo("years", "months", "weeks", "days", "hours", "minutes", "seconds", "milliseconds")
@return {Duration}