return Region(m[k].To)
	}
	return 0
}

const (
	iso3166UserAssigned = 1 << iota
	ccTLD
	bcp47Region
)

func (r Region) typ() byte {
	return regionTypes[r]
}

// String returns the BCP 47 representation for the region.
// It returns "ZZ" for an unspecified region.
func (r Region) String() string {
	if r < isoRegionOffset {
		if r == 0 {
			return "ZZ"

func getSigningKey(secretKey string, t time.Time, region string, stype serviceType) []byte {
	date := sumHMAC([]byte("AWS4"+secretKey), []byte(t.Format(yyyymmdd)))
	regionBytes := sumHMAC(date, []byte(region))
	service := sumHMAC(regionBytes, []byte(stype))
	signingKey := sumHMAC(service, []byte("aws4_request"))
	return signingKey
}

// getSignature final signature in hexadecimal form.

	Type string
}

// Region provides details about a Region event.
type Region struct {
	// Task is the ID of the task this region is associated with.
	Task TaskID

	// Type is the regionType that was passed to runtime/trace.StartRegion or runtime/trace.WithRegion.
	Type string
}

// Log provides details about a Log event.
type Log struct {
	// Task is the ID of the task this region is associated with.