_, _ = w.Write([]byte("h2c upgrade not allowed"))
			return
		}
		h.ServeHTTP(w, r)
	})
}

func isH2CUpgrade(h http.Header) bool {
	return httpguts.HeaderValuesContainsToken(h[textproto.CanonicalMIMEHeaderKey("Upgrade")], "h2c") &&
		httpguts.HeaderValuesContainsToken(h[textproto.CanonicalMIMEHeaderKey("Connection")], "HTTP2-Settings")

	'z':  true,
	'|':  true,
	'~':  true,
}

func IsTokenRune(r rune) bool {
	return r < utf8.RuneSelf && isTokenTable[byte(r)]
}

// HeaderValuesContainsToken reports whether any string in values
// contains the provided token, ASCII case-insensitively.
func HeaderValuesContainsToken(values []string, token string) bool {
	for _, v := range values {
		if headerValueContainsToken(v, token) {
			return true
		}
	}

	// advertise that unless the incoming client request thought it was worth
	// mentioning.) Note that we look at req.Header, not outreq.Header, since
	// the latter has passed through removeHopByHopHeaders.
	if httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") {
		outreq.Header.Set("Te", "trailers")
	}

	// After stripping all the hop-by-hop connection headers above, add back any

}

// isProtocolSwitchHeader reports whether the request or response header
// is for a protocol switch.
func isProtocolSwitchHeader(h Header) bool {
	return h.Get("Upgrade") != "" &&
		httpguts.HeaderValuesContainsToken(h["Connection"], "Upgrade")

	if major < 1 {
		return true
	}

	conv := header["Connection"]
	hasClose := httpguts.HeaderValuesContainsToken(conv, "close")
	if major == 1 && minor == 0 {
		return hasClose || !httpguts.HeaderValuesContainsToken(conv, "keep-alive")
	}

	if hasClose && removeCloseHeader {
		header.Del("Connection")
	}

	return hasClose
}

	sc.serveG.check()

	var tlsState *tls.ConnectionState // nil if not scheme https
	if rp.scheme == "https" {
		tlsState = sc.tlsState
	}

	needsContinue := httpguts.HeaderValuesContainsToken(rp.header["Expect"], "100-continue")
	if needsContinue {
		rp.header.Del("Expect")
	}
	// Merge Cookie headers into one "; "-delimited value.
	if cookies := rp.header["Cookie"]; len(cookies) > 1 {

				}
				count := 0
				trace := &httptrace.ClientTrace{
					WroteHeaderField: func(key string, field []string) {
						if key != "Connection" {
							return
						}
						if httpguts.HeaderValuesContainsToken(field, "close") {
							count += 1
						}
					},
				}
				req = req.WithContext(httptrace.WithClientTrace(req.Context(), trace))
				req.Close = tc.close
				res, err := c.Do(req)