creds.go
func (permaCreds *Credentials) CreateTemporaryCredentials(duration time.Duration, scopes ...string) (tempCreds *Credentials, err error) {
	return permaCreds.CreateNamedTemporaryCredentials("", duration, scopes...)
}
func (permaCreds *Credentials) CreateTemporaryCredentials(duration time.Duration, scopes ...string) (tempCreds *Credentials, err error) {
	return permaCreds.CreateNamedTemporaryCredentials("", duration, scopes...)
}
// CreateTemporaryCredentials is an alias for CreateNamedTemporaryCredentials
// with an empty name.