code: def _add_cwa_installed_tag(self, node_id: str) -> None:
      self.ec2_client.create_tags(
          Resources=[node_id],
          Tags=[
              {"Key": CLOUDWATCH_AGENT_INSTALLED_TAG, "Value": "True"}
          ],
      )
      logger.info(
          "Successfully add Unified CloudWatch Agent installed "
          "tag on {}".format(node_id)
      )
  
imports: import copy
  import hashlib
  import json
  import logging
  import os
  import time
  from enum import Enum
  from typing import Any, Callable, Dict, List, Union
  import botocore
  from ray.autoscaler._private.aws.utils import client_cache, resource_cache
  from ray.autoscaler.tags import NODE_KIND_HEAD, TAG_RAY_CLUSTER_NAME, TAG_RAY_NODE_KIND
label_desc: Use image node_id 18 for calling the CloudwatchHelper obj's underlying member method code with example usage: obj._add_cwa_installed_tag(node_id) without return types