docs: private void sendMessage(Message message) throws IOException {
          logger.debug("Sending> {}", message);
          int totalSize = 0;
          for (Field field : message.fields) {
              totalSize += field.getBytes().remaining();
          }
          ByteBuffer combined = ByteBuffer.allocate(totalSize);
          for (Field field : message.fields) {
              logger.debug("..sending> {}", field);
              combined.put(field.getBytes());
          }
          combined.flip();
          Util.writeFully(combined, channel);
      }