code: func CreateSignedEnvelope(txType common.HeaderType, channelID string, signer crypto.LocalSigner, dataMsg proto.Message, msgVersion int32, epoch uint64) (*common.Envelope, error) {
  	return CreateSignedEnvelopeWithTLSBinding(txType, channelID, signer, dataMsg, msgVersion, epoch, nil)
  }
docs: // CreateSignedEnvelope creates a signed envelope of the desired type, with
  // marshaled dataMsg and signs it