code: def test_deferred_env_var():
      assert str(TEST_ENV_VAR) == "value1"
  
      os.environ["TEST_ENV_VAR"] = "other2"
  
      assert str(TEST_ENV_VAR) == "other2"
  
file_path: ray/release/ray_release/tests/test_env.py
imports: import os
  import pytest
  from ray_release.config import DEFAULT_ANYSCALE_PROJECT
  from ray_release.env import load_environment, populate_os_env
  from ray_release.exception import ReleaseTestConfigError
  from ray_release.util import DeferredEnvVar
label_desc: Use image node_id 1 for calling a global function with example usage: test_deferred_env_var() without return types