def METHOD_NAME(aggregator, instance):
    c = GnatsdCheck(CHECK_NAME, {}, [instance])
    c.check(instance)
    aggregator.assert_metric_has_tag_prefix('gnatsd.varz.connections', 'gnatsd-server_id', at_least=1)
    aggregator.assert_metric_has_tag_prefix('gnatsd.connz.connections.foo-sub.out_msgs', 'gnatsd-cid', at_least=1)
    aggregator.assert_metric_has_tag_prefix('gnatsd.connz.connections.foo-sub.out_msgs', 'gnatsd-ip', at_least=1)
    aggregator.assert_metric_has_tag_prefix('gnatsd.connz.connections.foo-sub.out_msgs', 'gnatsd-name', at_least=1)
    aggregator.assert_metric_has_tag_prefix('gnatsd.connz.connections.foo-sub.out_msgs', 'gnatsd-lang', at_least=1)
    aggregator.assert_metric_has_tag_prefix('gnatsd.connz.connections.foo-sub.out_msgs', 'gnatsd-version', at_least=1)
    route_ip = get_container_ip('docker_nats_serverA_1').replace('.', '_')
    aggregator.assert_metric_has_tag_prefix(
        'gnatsd.routez.routes.{}.in_msgs'.format(route_ip), 'gnatsd-rid', at_least=1
    )
    aggregator.assert_metric_has_tag_prefix(
        'gnatsd.routez.routes.{}.in_msgs'.format(route_ip), 'gnatsd-remote_id', at_least=1
    )
    aggregator.assert_metric_has_tag_prefix('gnatsd.routez.routes.{}.in_msgs'.format(route_ip), 'gnatsd-ip', at_least=1)