docs: private static ByteBuf writePayload(
  			final ByteBufAllocator alloc,
  			final long requestId,
  			final MessageType messageType,
  			final byte[] payload) {
  
  		final int frameLength = HEADER_LENGTH + REQUEST_ID_SIZE + payload.length;
  		final ByteBuf buf = alloc.ioBuffer(frameLength + Integer.BYTES);
  
  		buf.writeInt(frameLength);
  		writeHeader(buf, messageType);
  		buf.writeLong(requestId);
  		buf.writeBytes(payload);
  		return buf;
  	}