code: def delete_sns_topic(topic_arn) -> None:
      boto3.client("sns").delete_topic(TopicArn=topic_arn)
  
file_path: airflow/tests/system/providers/amazon/aws/example_rds_event.py
imports: from __future__ import annotations
  from datetime import datetime
  import boto3
  from airflow.decorators import task
  from airflow.models.baseoperator import chain
  from airflow.models.dag import DAG
  from airflow.providers.amazon.aws.operators.rds import RdsCreateDbInstanceOperator, RdsCreateEventSubscriptionOperator, RdsDeleteDbInstanceOperator, RdsDeleteEventSubscriptionOperator
  from airflow.utils.trigger_rule import TriggerRule
  from tests.system.providers.amazon.aws.utils import ENV_ID_KEY, SystemTestContextBuilder
  from tests.system.utils import get_test_run
label_desc: Use image node_id 2 for calling a global function with example usage: delete_sns_topic(topic_arn) without return types