func (r *Request) SetBasicAuth(username, password string) {
	r.Header.Set("Authorization", "Basic "+basicAuth(username, password))
}

// parseRequestLine parses "GET /foo HTTP/1.1" into its three parts.
func parseRequestLine(line string) (method, requestURI, proto string, ok bool) {
	method, rest, ok1 := strings.Cut(line, " ")
	requestURI, proto, ok2 := strings.Cut(rest, " ")
	if !ok1 || !ok2 {