public static function minOf(LocalDateTime ...$times) : LocalDateTime
    {
        if (! $times) {
            throw new DateTimeException(__METHOD__ . ' does not accept less than 1 parameter.');
        }

        $min = LocalDateTime::max();

        foreach ($times as $time) {
            if ($time->isBefore($min)) {
                $min = $time;
            }
        }

        return $min;
    }