docs: private void tryFinishCurrentBufferBuilder(int targetChannel) {
  		if (!bufferBuilders[targetChannel].isPresent()) {
  			return;
  		}
  		BufferBuilder bufferBuilder = bufferBuilders[targetChannel].get();
  		bufferBuilders[targetChannel] = Optional.empty();
  		numBytesOut.inc(bufferBuilder.finish());
  		numBuffersOut.inc();
  	}