header.go
func (h *ResponseHeader) VisitAllCookie(f func(key, value []byte)) {
	visitArgs(h.cookies, f)
}
func (h *ResponseHeader) VisitAllCookie(f func(key, value []byte)) {
	visitArgs(h.cookies, f)
}
// VisitAllCookie calls f for each response cookie.
//
// Cookie name is passed in key and the whole Set-Cookie header value
// is passed in value on each f invocation. Value may be parsed
// with Cookie.ParseBytes().
//
// f must not retain references to key and/or value after returning.