class Gem::Resolv::DNS::Requester::TCP

def sender(msg, data, host=@host, port=@port)
  unless host == @host && port == @port
    raise RequestError.new("host/port don't match: #{host}:#{port}")
  end
  id = DNS.allocate_request_id(@host, @port)
  request = msg.encode
  request[0,2] = [request.length, id].pack('nn')
  return @senders[[nil,id]] = Sender.new(request, data, @socks[0])
end