if test.accept != "" {
			req.Header.Set("Accept-Encoding", test.accept)
		}
		res, err := tr.RoundTrip(req)
		if err != nil {
			t.Errorf("%d. RoundTrip: %v", i, err)
			continue
		}
		var body []byte
		if test.compressed {
			var r *gzip.Reader
			r, err = gzip.NewReader(res.Body)
			if err != nil {

	if res != nil {
		defer res.Body.Close()
	}
	if mode == http2Mode {
		// In HTTP/2, the result depends on a race. If the client has received the
		// server's SETTINGS before RoundTrip starts sending the request, then RoundTrip
		// will fail with an error. Otherwise, the client should receive a 431 from the
		// server.
		if err == nil && res.StatusCode != 431 {