# File lib/dnsruby/message/header.rb, line 103
  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