code: def test_return_none_for_invalid_class_name(imagenet):
      class_index = imagenet["invalid class name"]
  
      assert class_index is None
  
file_path: flashtorch/tests/test_imagenet.py
imports: import pytest
  from collections.abc import Iterable
  from flashtorch.utils import ImageNetIndex
label_desc: Use image node_id 12 for calling a global function with example usage: test_return_none_for_invalid_class_name(imagenet) without return types