equals(other) {
    return (
      this.isValid &&
      other.isValid &&
      this.valueOf() === other.valueOf() &&
      this.zone.equals(other.zone) &&
      this.loc.equals(other.loc)
    );
  }
Equality check
Two DateTimes are equal if and only if they represent the same millisecond, have the same zone and location, and are both valid.
To compare just the millisecond values, use `+dt1 === +dt2`.
@param {DateTime} other - the other DateTime
@return {boolean}