tarball/tarball_reference.go
func (r *tarballReference) ConfigUpdate(config imgspecv1.Image, annotations map[string]string) error {
	r.config = config
	if r.annotations == nil {
		r.annotations = make(map[string]string)
	}
	for k, v := range annotations {
		r.annotations[k] = v
	}
	return nil
}
func (r *tarballReference) ConfigUpdate(config imgspecv1.Image, annotations map[string]string) error {
	r.config = config
	if r.annotations == nil {
		r.annotations = make(map[string]string)
	}
	for k, v := range annotations {
		r.annotations[k] = v
	}
	return nil
}
// ConfigUpdate updates the image's default configuration and adds annotations
// which will be visible in source images created using this reference.