@Override
      public boolean hasNext() {
        return deviceIterator.hasNext();
      }
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