public int getRows() {
      return rows;
    }
This class works as the InputSplit of Performance Evaluation MapReduce InputFormat, and the
Record Value of RecordReader. Each map task will only read one record from a PeInputSplit, the
record value is the PeInputSplit itself.
hbase-rest/src/test/java/org/apache/hadoop/hbase/rest/PerformanceEvaluation.java