@Override
      public DeviceInfo next() {
        IDeviceID deviceId = deviceIterator.next();
        return new DeviceInfo(
            deviceId,
            deviceTimeIndex.getStartTime(deviceId).get(),
            deviceTimeIndex.getEndTime(deviceId).get());
      }
The TsFile is unsealed means there may be more data which will be inserted into this file.

@return Whether the TsFile is unsealed.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/compaction/selector/utils/TsFileResourceCandidate.java