golang - marshal PKCS8 private key?

Question

Is there a way to marshal a PKCS8 private key in go 1.5?
e.g. something similar to or starting from x509.MarshalPKCS1PrivateKey?

Answer 1

Since the above answer was written, go 1.10 has been released with a x509.MarshalPKCS8PrivateKey method.