code: private static void writeHeader(final ByteBuf buf, final MessageType messageType) {
  		buf.writeInt(VERSION);
  		buf.writeInt(messageType.ordinal());
  	}
docs: Helper for serializing the header.
  
  @param buf         The {@link ByteBuf} to serialize the header into.
  @param messageType The {@link MessageType} of the message this header refers to.