signature/mechanism_openpgp.go
func (m *openpgpSigningMechanism) Sign(input []byte, keyIdentity string) ([]byte, error) {
	return nil, SigningNotSupportedError("signing is not supported in github.com/containers/image built with the containers_image_openpgp build tag")
}
func (m *openpgpSigningMechanism) Sign(input []byte, keyIdentity string) ([]byte, error) {
	return nil, SigningNotSupportedError("signing is not supported in github.com/containers/image built with the containers_image_openpgp build tag")
}
// Sign creates a (non-detached) signature of input using keyIdentity.
// Fails with a SigningNotSupportedError if the mechanism does not support signing.