code: def set_env_id() -> str:
      """
      Retrieves or generates an Environment ID, validate that it is suitable,
      export it as an Environment Variable, and return it.
  
      If an Environment ID has already been generated, use that.
      Otherwise, try to fetch it and export it as an Environment Variable.
      If there is not one available to fetch then generate one and export it as an Environment Variable.
  
      :return: A valid System Test Environment ID.
      """
      env_id: str = str(
          fetch_variable(ENV_ID_ENVIRON_KEY, DEFAULT_ENV_ID)
      )
      env_id = _validate_env_id(env_id)
  
      os.environ[ENV_ID_ENVIRON_KEY] = env_id
      return env_id
  
imports: from __future__ import annotations
  import inspect
  import json
  import logging
  import os
  import time
  from pathlib import Path
  from typing import TYPE_CHECKING
  from uuid import uuid4
  import boto3
  from botocore.exceptions import ClientError, NoCredentialsError
  from airflow.decorators import task
  from airflow.providers.amazon.aws.hooks.ssm import SsmHook
  from airflow.utils.state import State
  from airflow.utils.trigger_rule import TriggerRule
label_desc: Use image node_id 5 for calling a global function with example usage: set_env_id() and returns: env_id