if len(v) == 0 {
		return false
	}
	for i := 0; i < len(v); i++ {
		if !isTokenTable[v[i]] {
			return false
		}
	}
	return true
}

// ValidHostHeader reports whether h is a valid host header.
func ValidHostHeader(h string) bool {
	// The latest spec is actually this:
	//
	// http://tools.ietf.org/html/rfc7230#section-5.4
	//     Host = uri-host [ ":" port ]
	//
	// Where uri-host is: