'Sets a Balancer\'s health monitor.  This method blocks until the update
request has been processed and the balancer is in a RUNNING state
again.
:param balancer: Balancer to update.
:type  balancer: :class:`LoadBalancer`
:param health_monitor: Health Monitor for the balancer.
:type  health_monitor: :class:`RackspaceHealthMonitor`
:return: Updated Balancer.
:rtype: :class:`LoadBalancer`'

def ex_update_balancer_health_monitor(self, balancer, health_monitor):

    accepted = self.ex_update_balancer_health_monitor_no_poll(balancer, health_monitor)
    if (not accepted):
        msg = 'Update    health    monitor    request    not    accepted'
        raise LibcloudError(msg, driver=self)
    return self._get_updated_balancer(balancer)
