@Override
            public boolean executeWith(Object a, int b) {
              HeapDataOutputStream chunk = (HeapDataOutputStream) a;
              last = b > 0;
              try {
                boolean okay = sendChunk(recipient, processorId, dm, chunk, seriesNum, msgNum++,
                    numSeries, last);
                return okay;
              } catch (CancelException e) {
                return false;
              }
            }
@param a byte[] chunk
@param b positive if last chunk
@return true to continue to next chunk
geode-core/src/main/java/org/apache/geode/internal/cache/tx/RemoteFetchKeysMessage.java