writeShort(id);
writeShort(multicast ? 0 : id);
    void finish() throws IOException    {	int save = off;	off = 0;	writeShort(id);	writeShort(flags);	writeShort(numQuestions);	writeShort(numAnswers);	writeShort(numAuthorities);	writeShort(numAdditionals);	off = save;    }