def ex_update_balancer_error_page(self, balancer, page_content):
        accepted = self.ex_update_balancer_error_page_no_poll(balancer,
                                                              page_content)
        if not accepted:
            msg = 'Update error page request not accepted'
            raise LibcloudError(msg, driver=self)

        return self._get_updated_balancer(balancer)
Updates a Balancer's custom error page.  This method blocks until
dataset/ETHPy150Open apache/libcloud/libcloud/loadbalancer/drivers/rackspace.py/RackspaceLBDriver.ex_update_balancer_error_page