@Override
        protected R getFinalResult() {
          synchronized (lock) {
            return min;
          }
        }
This client class is for invoking the aggregate functions deployed on the Region Server side via
the AggregateService. This class will implement the supporting functionality for
summing/processing the individual results obtained from the AggregateService for each region.
hbase-endpoint/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AsyncAggregationClient.java