return StringUtil.EMPTY;
        }
        return date.format(DateTimeFormatter.ofPattern(format, Locale.ROOT));
    }

    /**
     * Formats a duration in milliseconds to a human-readable string.
     *
     * @param durationMillis the duration in milliseconds
     * @return formatted duration string (e.g., "2 days 14:30:25.123" or "14:30:25.123")
     */