private static TTimePartitionSlot getCurrentTimePartitionSlot() {
    if ("ms".equals(timestampPrecision)) {
      return new TTimePartitionSlot(System.currentTimeMillis());
    } else if ("us".equals(timestampPrecision)) {
      return new TTimePartitionSlot(System.currentTimeMillis() * 1000);
    } else {
      return new TTimePartitionSlot(System.currentTimeMillis() * 1000_000);
    }
  }
@return The time partition slot corresponding to current timestamp. Note that we do not shift
    the start time to the correct starting point, since this interface only constructs a time
    reference position for the partition table cleaner.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/procedure/PartitionTableAutoCleaner.java