*/
private <R, S, P extends Message, Q extends Message, T extends Message>
Pair<NavigableMap<byte[], List<S>>, List<S>>
getMedianArgs(final HTable table,
final ColumnInterpreter<R, S, P, Q, T> ci, final Scan scan) throws Throwable {
final AggregateRequest requestArg = validateArgAndGetPB(scan, ci, false);
final NavigableMap<byte[], List<S>> map =
new TreeMap<byte[], List<S>>(Bytes.BYTES_COMPARATOR);
class StdCallback implements Batch.Callback<List<S>> {
S sumVal = null, sumWeights = null;