public ThreadLocalWorkerGlobalCommUsage() {
threadReducerMap = Maps.newHashMapWithExpectedSize(
WorkerAggregatorHandler.this.reducerMap.size());
UnsafeByteArrayOutputStream out = new UnsafeByteArrayOutputStream();
UnsafeReusableByteArrayInput in = new UnsafeReusableByteArrayInput();
for (Entry<String, Reducer<Object, Writable>> entry :
reducerMap.entrySet()) {
ReduceOperation<Object, Writable> globalReduceOp =
entry.getValue().getReduceOp();