# File lib/Dnsruby/message.rb, line 491
    def encode(msg)
      msg.put_pack('nnnnnn',
        @id,
        (@qr?1:0) << 15 |
        (@opcode.code & 15) << 11 |
        (@aa?1:0) << 10 |
        (@tc?1:0) << 9 |
        (@rd?1:0) << 8 |
        (@ra?1:0) << 7 |
        (@ad?1:0) << 5 | 
        (@cd?1:0) << 4 |
        (@rcode.code & 15),
        @qdcount,
        @ancount,
        @nscount,
        @arcount)
    end