pkg          []uint32 // indices of referenced package by PkgIdx (index into loader.objs array)
	ndef         int      // cache goobj.Reader.NSym()
	nhashed64def int      // cache goobj.Reader.NHashed64Def()
	nhasheddef   int      // cache goobj.Reader.NHashedDef()
	objidx       uint32   // index of this reader in the objs slice
}

// Total number of defined symbols (package symbols, hashed symbols, and

			if h == nil {
				continue
			}
			if vs.Headers == nil {
				vs.Headers = &istio.Headers{}
			}
			vs.Headers.Request = h
		case k8s.GRPCRouteFilterResponseHeaderModifier:
			h := createHeadersFilter(filter.ResponseHeaderModifier)
			if h == nil {
				continue
			}
			if vs.Headers == nil {
				vs.Headers = &istio.Headers{}
			}
			vs.Headers.Response = h
		case k8s.GRPCRouteFilterRequestMirror:

				overrideCheck(&opt)
				src.CallOrFail(t, opt)
			})
			t.NewSubTest("headers allow").Run(func(t framework.TestContext) {
				opt := opt.DeepCopy()
				opt.HTTP.Path = "/headers"
				if opt.HTTP.Headers == nil {
					opt.HTTP.Headers = map[string][]string{}
				}
				opt.HTTP.Headers.Set("x-test-header", "match")
				opt.Check = check.OK()
				overrideCheck(&opt)
				src.CallOrFail(t, opt)

			if !canBeConvertedToPresentMatch(stringMatch) {
				matcher.TreatMissingHeaderAsEmpty = true
			}
			out.Headers = append(out.Headers, matcher)
		}
	}

	// guarantee ordering of headers
	sort.Slice(out.Headers, func(i, j int) bool {
		return out.Headers[i].Name < out.Headers[j].Name
	})

	if in.Uri != nil {
		switch m := in.Uri.MatchType.(type) {
		case *networking.StringMatch_Exact:

		Name:             "acme",
	},
	Spec: &networking.VirtualService{
		Hosts:    []string{"headers.test.istio.io"},
		Gateways: []string{"some-gateway"},
		Http: []*networking.HTTPRoute{
			{
				Match: []*networking.HTTPMatchRequest{
					{
						Name: "headers-only",
						Headers: map[string]*networking.StringMatch{
							"version": {
								MatchType: &networking.StringMatch_Exact{

			headerMap[strings.ToLower(k)] = vv
		}
	}

	// Get header keys.
	headers := []string{"host"}
	for k := range headerMap {
		headers = append(headers, k)
	}
	sort.Strings(headers)

	// Get canonical headers.
	var buf bytes.Buffer
	for _, k := range headers {
		buf.WriteString(k)
		buf.WriteByte(':')
		switch {
		case k == "host":

      --feature-gates="${FEATURE_GATES}" \
      --external-hostname="${EXTERNAL_HOSTNAME}" \
      --requestheader-username-headers=X-Remote-User \
      --requestheader-group-headers=X-Remote-Group \
      --requestheader-extra-headers-prefix=X-Remote-Extra- \
      --requestheader-client-ca-file="${CERT_DIR}/request-header-ca.crt" \
      --requestheader-allowed-names=system:auth-proxy \

	}
	if req.Header == nil {
		req.closeBody()
		return nil, errors.New("http: nil Request.Header")
	}
	scheme := req.URL.Scheme
	isHTTP := scheme == "http" || scheme == "https"
	if isHTTP {
		// Validate the outgoing headers.
		if err := validateHeaders(req.Header); err != "" {
			req.closeBody()
			return nil, fmt.Errorf("net/http: invalid header %s", err)
		}

		}
		if c := r.Header.Get("Proxy-Connection"); c != "" {
			t.Errorf("handler got Proxy-Connection header value %q", c)
		}
		if g, e := r.Host, "some-name"; g != e {
			t.Errorf("backend got Host header %q, want %q", g, e)
		}
		w.Header().Set("Trailers", "not a special header field name")
		w.Header().Set("Trailer", "X-Trailer")
		w.Header().Set("X-Foo", "bar")
		w.Header().Set("Upgrade", "foo")

	}

	// Subsequent lines: Key: value.
	mimeHeader, err := tp.ReadMIMEHeader()
	if err != nil {
		return nil, err
	}
	req.Header = Header(mimeHeader)
	if len(req.Header["Host"]) > 1 {
		return nil, fmt.Errorf("too many Host headers")
	}

	// RFC 7230, section 5.3: Must treat
	//	GET /index.html HTTP/1.1
	//	Host: www.google.com
	// and