code: def test_set_env_id_generates_if_required(self):
      # No environment variable nor SSM value has been found
      result = set_env_id()
  
      assert len(result) == DEFAULT_ENV_ID_LEN + len(
          DEFAULT_ENV_ID_PREFIX
      )
      assert result.isalnum()
      assert result.islower()
  
file_path: airflow/tests/providers/amazon/aws/system/utils/test_helpers.py
imports: from __future__ import annotations
  import os
  import sys
  from io import StringIO
  from unittest.mock import ANY, patch
  import pytest
  from moto import mock_ssm
  from tests.system.providers.amazon.aws import utils
  from tests.system.providers.amazon.aws.utils import DEFAULT_ENV_ID_LEN, DEFAULT_ENV_ID_PREFIX, ENV_ID_ENVIRON_KEY, INVALID_ENV_ID_MSG, LOWERCASE_ENV_ID_MSG, NO_VALUE_MSG, _validate_env_id, set_env_id
label_desc: Use image node_id 4 for calling the TestAmazonSystemTestHelpers obj's underlying member method code with example usage: obj.test_set_env_id_generates_if_required() without return types