@Override
  public void putStartTime(IDeviceID deviceId, long time) {
    this.startTime = time;
  }
end times. The value is Long.MIN_VALUE if it's an unsealed sequence tsfile
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/tsfile/timeindex/FileTimeIndex.java