@Override
    public String toString() {
      return MoreObjects.toStringHelper(this).add("numRows", numRows)
        .add("elapsedTime", elapsedTime).toString();
    }
Record the results from a single {@link PerformanceEvaluation} job run.
hbase-it/src/test/java/org/apache/hadoop/hbase/IntegrationTestRegionReplicaPerf.java