res.Trailer[k] = vv2
			}
		}
	}
	for k, vv := range rw.HeaderMap {
		if !strings.HasPrefix(k, http.TrailerPrefix) {
			continue
		}
		if res.Trailer == nil {
			res.Trailer = make(http.Header)
		}
		for _, v := range vv {
			res.Trailer.Add(strings.TrimPrefix(k, http.TrailerPrefix), v)
		}
	}
	return res
}

// parseContentLength trims whitespace from s and returns -1 if no value

pkg math/rand, type Source64 interface { Int63, Seed, Uint64 }
pkg math/rand, type Source64 interface, Seed(int64)
pkg math/rand, type Source64 interface, Uint64() uint64
pkg net/http, const TrailerPrefix ideal-string
pkg net/http, const TrailerPrefix = "Trailer:"
pkg net/http/httptrace, type ClientTrace struct, TLSHandshakeDone func(tls.ConnectionState, error)
pkg net/http/httptrace, type ClientTrace struct, TLSHandshakeStart func()

//	https://pkg.go.dev/net/http#example-ResponseWriter-Trailers
const TrailerPrefix = "Trailer:"

// finalTrailers is called after the Handler exits and returns a non-nil
// value if the Handler set any trailers.
func (w *response) finalTrailers() Header {
	var t Header
	for k, vv := range w.handlerHeader {
		if kk, found := strings.CutPrefix(k, TrailerPrefix); found {
			if t == nil {
				t = make(Header)
			}

		http.SetCookie(w, &http.Cookie{Name: "flavor", Value: "chocolateChip"})
		w.WriteHeader(backendStatus)
		w.Write([]byte(backendResponse))
		w.Header().Set("X-Trailer", "trailer_value")
		w.Header().Set(http.TrailerPrefix+"X-Unannounced-Trailer", "unannounced_trailer_value")
	}))
	defer backend.Close()
	backendURL, err := url.Parse(backend.URL)
	if err != nil {
		t.Fatal(err)
	}
	proxyHandler := NewSingleHostReverseProxy(backendURL)

		http.NewResponseController(rw).Flush()
	}

	if len(res.Trailer) == announcedTrailers {
		copyHeader(rw.Header(), res.Trailer)
		return
	}

	for k, vv := range res.Trailer {
		k = http.TrailerPrefix + k
		for _, v := range vv {
			rw.Header().Add(k, v)
		}
	}
}

var inOurTests bool // whether we're in our own tests

// shouldPanicOnCopyError reports whether the reverse proxy should

			streamID:  rws.stream.id,
			h:         rws.handlerHeader,
			trailers:  rws.trailers,
			endStream: true,
		})
		return len(p), err
	}
	return len(p), nil
}

// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys
// that, if present, signals that the map entry is actually for
// the response trailers, and not the response headers. The prefix

		{"StatusUpgradeRequired", Const, 7},
		{"StatusUseProxy", Const, 0},
		{"StatusVariantAlsoNegotiates", Const, 7},
		{"StripPrefix", Func, 0},
		{"TimeFormat", Const, 0},
		{"TimeoutHandler", Func, 0},
		{"TrailerPrefix", Const, 8},
		{"Transport", Type, 0},
		{"Transport.Dial", Field, 0},
		{"Transport.DialContext", Field, 7},
		{"Transport.DialTLS", Field, 4},
		{"Transport.DialTLSContext", Field, 14},