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

:param unicode author: The identity of the message's author.
:param unicode attributes: A string metadata field you can use to store any data you wish.
:param datetime date_created: The date that this resource was created.
:param datetime date_updated: The date that this resource was last updated.
:param unicode body: The contents of the message.

:returns: Updated MessageInstance
:rtype: twilio.rest.messaging.v1.session.message.MessageInstance