private void iterateHasNullsSelectionWithAggregationSelection(
        VectorAggregationBufferRow[] aggregationBufferSets,
        int aggregateIndex,
        int batchSize,
        int[] selection,
        boolean[] isNull) {

        for (int j=0; j < batchSize; ++j) {
          int i = selection[j];
          if (!isNull[i]) {
            Aggregation myagg = getCurrentAggregationBuffer(
              aggregationBufferSets,
              aggregateIndex,
              j);
            myagg.count++;
          }
        }
    }
class for storing the current aggregate value.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/aggregates/VectorUDAFCount.java