def METHOD_NAME(self):
    session_factory = self.replay_flight_data("test_cfn_add_tag_w_params")
    p = self.load_policy(
        {
            "name": "cfn-add-tag",
            "resource": "cfn",
            "filters": [{"StackName": "mosdef2"}],
            "actions": [{"type": "tag", "tags": {"App": "Ftw"}}],
        },
        session_factory=session_factory,
    )
    resources = p.run()
    self.assertEqual(len(resources), 1)
    client = session_factory(region="us-east-1").client("cloudformation")
    rtags = {t["Key"]: t["Value"] for t in resources[0]["Tags"]}
    self.assertEqual(rtags, {"Env": "Dev"})
    tags = {
        t["Key"]: t["Value"]
        for t in client.describe_stacks(StackName=resources[0]["StackName"])[
            "Stacks"
        ][0]["Tags"]
    }
    self.assertEqual(tags, {"Env": "Dev", "App": "Ftw"})