In protocol.go the Propose protobuf is writen using a function called writeMsgCtx. This method accepts a w msgio.Writer
func writeMsgCtx(ctx context.Context, w msgio.Writer, msg proto.Message) ([]byte, error)The msgio.Writer passed into writeMsgCtx is the s.insecureM writer which is set in the newSecureSession function. s.insecureM is created from a insecure io.ReadWriteCloser. This however, is already a msgio ReadWrite.
- newSecureSession is called from
NewSessionin interface.go