ruleset

var (
	AuthorizationRule = func(header GetHeader) bool {
		return header("Authorization") == "" &&
			header("Proxy-Authenticate") == ""
	}

	MustRevalidateRule = func(header GetHeader) bool {
		return header("Must-Revalidate") == ""
	}

	ZeroMaxAgeRule = func(header GetHeader) bool {
		return header("S-Maxage") != "0" &&
			header("Max-Age") != "0"
	}

	NoCacheRule = func(header GetHeader) bool {
		return header("No-Cache") != "true"
	}
)

var EmptyHeaderPredicate = func(GetHeader) bool {
	return true
}