public LlapFileSystemStatisticsData merge(FileSystem.Statistics.StatisticsData other) {
      this.bytesRead += other.getBytesRead();
      this.bytesWritten += other.getBytesWritten();
      this.readOps += other.getReadOps();
      this.largeReadOps += other.getLargeReadOps();
      this.writeOps += other.getWriteOps();
      return this;
    }
Convenience class over Hadoop's FileSystem.Statistics.StatisticsData.
Unfortunately, neither the fields, nor the convenience methods (e.g. StatisticsData.add, StatisticsData.negate)
are available here as they are package protected, so we cannot reuse them.
llap-common/src/java/org/apache/hadoop/hive/llap/LlapThreadLocalStatistics.java