def METHOD_NAME(dd_agent_check, aggregator, instance, iis_host):
    """
    Assert the app pool state when it is running.
    The status is used to calculate the serive check for app pools.
    """
    start_iis()
    aggregator = dd_agent_check(instance)
    value = IIS_APPLICATION_POOL_STATE['Running']
    assert value == 3
    aggregator.assert_metric(
        'iis.app_pool.state', value=value, tags=normalize_tags(['app_pool:DefaultAppPool', iis_host])
    )