code: def mock_app_config_env_var(app_config_path):
      with mock.patch.dict(
          os.environ, {"FIFTYONE_APP_CONFIG_PATH": app_config_path}
      ):
          yield
  
file_path: fiftyone/tests/unittests/plugins/core_tests.py
imports: import os
  import fiftyone
  import pytest
  import json
  import yaml
  from unittest import mock
  import fiftyone.plugins
label_desc: Use image node_id 2 for calling a global function with example usage: mock_app_config_env_var(app_config_path) without return types