The new type [KeepAliveConfig] permits fine-tuning the keep-alive
options for TCP connections, via a new [TCPConn.SetKeepAliveConfig]

	if err != nil {
		t.Fatalf("%v: %v\n%s", cmd, err, string(out))
	}
	syms := make(map[string]string)
	scanner := bufio.NewScanner(bytes.NewReader(out))
	for scanner.Scan() {
		f := strings.Fields(scanner.Text())
		if len(f) < 3 {
			continue
		}
		syms[f[2]] = f[0]
	}
	if err := scanner.Err(); err != nil {
		t.Fatalf("error reading symbols: %v", err)
	}
	return syms
}

[Cookie] now preserves double quotes surrounding a cookie value.
The new [Cookie.Quoted] field indicates whether the [Cookie.Value]