'Updates a Balancer\'s custom error page.  This method blocks until
the update request has been processed and the balancer is in a
RUNNING state again.
:param balancer: Balancer to update the custom error page for.
:type  balancer: :class:`LoadBalancer`
:param page_content: HTML content for the custom error page.
:type  page_content: ``str``
:return: Updated Balancer.
:rtype:  :class:`LoadBalancer`'

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)
