@Override
  public void getAvg(RpcController controller, AggregateRequest request,
    RpcCallback<AggregateResponse> done) {

  }
Mocks the behavior of getMin() in the real AggregateImplementation. Makes some fake data to
send back some partial results, and then finally a complete result.
hbase-endpoint/src/test/java/org/apache/hadoop/hbase/client/MockPartialResultAggregateImplemention.java