@Override
          public void onCompletion(Long result, Exception callbackException) {
            streamed += result;
            channelWriteException = callbackException;
            writeToChannel();
          }
Writes continuously to the provided {@link AsyncWritableChannel} until {@link #streamSize} is reached.
ambry-tools/src/main/java/com/github/ambry/tools/perf/rest/PerfRSC.java