def METHOD_NAME():
    cw = boto3.client("cloudwatch", region_name="eu-central-1")
    cw.put_metric_alarm(
        AlarmName="testalarm",
        EvaluationPeriods=1,
        ComparisonOperator="GreaterThanThreshold",
        Period=60,
        MetricName="test",
        Namespace="test",
    )
    alarms = cw.describe_alarms()
    alarm_arn = alarms["MetricAlarms"][0]["AlarmArn"]
    # List 0 tags - none have been added
    assert cw.list_tags_for_resource(ResourceARN=alarm_arn)["Tags"] == []
    # Tag the Alarm for the first time
    cw.tag_resource(ResourceARN=alarm_arn, Tags=[{"Key": "tk", "Value": "tv"}])
    assert len(cw.list_tags_for_resource(ResourceARN=alarm_arn)["Tags"]) == 1