@Override
    public void operationComplete(ChannelProgressiveFuture future) {
      if (future.isSuccess()) {
        logger.trace("Response sending complete on channel {}", ctx.channel());
        completeRequest(request == null || !request.isKeepAlive(), false, true);
      } else {
        handleChannelWriteFailure(future.cause(), true);
      }
    }
Called once the write is complete i.e. either all chunks that were needed to be written were written or there
was an error  writing the chunks.
@param future the {@link ChannelProgressiveFuture} that is being listened on.
ambry-rest/src/main/java/com/github/ambry/rest/NettyResponseChannel.java