code: func UnmarshalEnvelopeOrPanic(encoded []byte) *cb.Envelope {
  	envelope, err := UnmarshalEnvelope(encoded)
  	if err != nil {
  		panic(err)
  	}
  	return envelope
  }
docs: // UnmarshalEnvelopeOrPanic unmarshals bytes to an Envelope structure or panics
  // on error