public RegularTimePeriod next() {
        
        Second result = null;
        if (this.second != LAST_SECOND_IN_MINUTE) {
            result = new Second(this.second + 1, getMinute());
        }
        else {
            Minute next = (Minute) getMinute().next();
            if (next != null) {
                result = new Second(FIRST_SECOND_IN_MINUTE, next);
            }
        }
        return result;