public String eval(Long timestamp, Long roundTime, String format) {
        try {
            LocalDateTime dateTime = LocalDateTime.ofInstant(
                    Instant.ofEpochSecond(timestamp - timestamp % roundTime),
                    DEFAULT_ZONE);
            DateTimeFormatter formatter = formatters.get(format);
            if (formatter == null) {
                formatter = DateTimeFormatter.ofPattern(format);
                formatters.put(format, formatter);
            }
            return dateTime.format(formatter);
        } catch (Exception e) {
            LOG.error("get formatted timestamp error, timestamp: {}, roundTime: {},format: {}",
                    timestamp, roundTime, format, e);
            return null;
        }
    }
Round timestamp and output formatted timestamp.
For example, if the input timestamp is 1702610371(s), the roundTime is 600(s), and the format is "yyyyMMddHHmm",
the formatted timestamp is "2023121510".

@param timestamp The input timestamp in seconds.
@param roundTime The round time in seconds.
@param format The format of the output timestamp.
@return The formatted timestamp.
inlong-sort/sort-core/src/main/java/org/apache/inlong/sort/function/RoundTimestampFunction.java