code: def fail_download():
      with mock.patch.dict(
          os.environ,
          {
              RAY_RUNTIME_ENV_FAIL_DOWNLOAD_FOR_TESTING_ENV_VAR: "1",
          },
      ):
          print("RAY_RUNTIME_ENV_FAIL_DOWNLOAD_FOR_TESTING enabled.")
          yield
  
file_path: ray/python/ray/tests/test_runtime_env_failure.py
imports: import os
  from unittest import mock
  import pytest
  from ray._private.ray_constants import RAY_RUNTIME_ENV_URI_PIN_EXPIRATION_S_DEFAULT
  from ray._private.runtime_env.packaging import RAY_RUNTIME_ENV_FAIL_DOWNLOAD_FOR_TESTING_ENV_VAR, RAY_RUNTIME_ENV_FAIL_UPLOAD_FOR_TESTING_ENV_VAR
  import ray
  from ray.exceptions import RuntimeEnvSetupError
label_desc: Use image node_id 2 for calling a global function with example usage: fail_download() without return types