def ip_addresses(self, value):
        """ :param value: a list of ip addresses """
        if not isinstance(value, list):
            raise ValueError('ip_addresses value must be a list')
        # in soem cases self.data might be none, so let's instantiate an empty dict
        if self.data is None:
            self.data = {}
        # update field
        self.data['ip_addresses'] = ', '.join(value)
:param value: a list of ip addresses