'Wrapper on message_subscribe, using users. If user_ids is not
provided, unsubscribe uid instead.'

@api.multi
def message_unsubscribe_users(self, user_ids=None):

    if (user_ids is None):
        user_ids = [self._uid]
    partner_ids = [user.partner_id.id for user in self.env['res.users'].browse(user_ids)]
    return self.message_unsubscribe(partner_ids)
