public void markAsSelected() {
    this.selected = true;
  }
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