'Updates the service plan on a node with monitoring
:param   node: The node to monitor
:type    node: :class:`Node`
:param   service_plan: The service plan, one of ESSENTIALS or
ADVANCED
:type    service_plan: ``str``
:rtype: ``bool``'

def ex_update_monitoring_plan(self, node, service_plan='ESSENTIALS'):

    update_node = ET.Element('changeServerMonitoringPlan', {'xmlns': TYPES_URN})
    update_node.set('id', node.id)
    ET.SubElement(update_node, 'servicePlan').text = service_plan
    result = self.connection.request_with_orgId_api_2('server/changeServerMonitoringPlan', method='POST', data=ET.tostring(update_node)).object
    response_code = findtext(result, 'responseCode', TYPES_URN)
    return (response_code in ['IN_PROGRESS', 'OK'])
