def update(self, body=values.unset, attributes=values.unset):
return self._proxy.update(body=body, attributes=attributes, )<EOL>
Update the MessageInstance

:param unicode body: The new message body string.
:param unicode attributes: The new attributes metadata field you can use to store any data you wish.

:returns: Updated MessageInstance
:rtype: twilio.rest.chat.v1.service.channel.message.MessageInstance