private void iterateHasNullsSelectionWithAggregationSelection(
      VectorAggregationBufferRow[] aggregationBufferSets,
      int aggregateIndex,
      long[] values,
      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.value += values[i];
      }
    }
  }
class for storing the current aggregate value.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/aggregates/VectorUDAFCountMerge.java