def create_json_map(test_files_to_run: List[str], json_output_file: str):
    """
    Creates a map from a list of tests to run to easily split them by category, when running parallelism of slow tests.

    Args:
        test_files_to_run (`List[str]`): The list of tests to run.
        json_output_file (`str`): The path where to store the built json map.
    """
    if json_output_file is None:
        return

    test_map = {}
    for test_file in test_files_to_run:
        # `test_file` is a path to a test folder/file, starting with `tests/`. For example,
        #   - `tests/models/bert/test_modeling_bert.py` or `tests/models/bert`
        #   - `tests/trainer/test_trainer.py` or `tests/trainer`
        #   - `tests/test_modeling_common.py`
        names = test_file.split(os.path.sep)
        if names[1] == "models":
            # take the part like `models/bert` for modeling tests
            key = os.path.sep.join(names[1:3])
        elif len(names) > 2 or not test_file.endswith(".py"):
            # test folders under `tests` or python files under them
            # take the part like tokenization, `pipeline`, etc. for other test categories
            key = os.path.sep.join(names[1:2])
        else:
            # common test files directly under `tests/`
            key = "common"

        if key not in test_map:
            test_map[key] = []
        test_map[key].append(test_file)

    # sort the keys & values
    keys = sorted(test_map.keys())
    test_map = {k: " ".join(sorted(test_map[k])) for k in keys}
    with open(json_output_file, "w", encoding="UTF-8") as fp:
        json.dump(test_map, fp, ensure_ascii=False)

    Creates a map from a list of tests to run to easily split them by category, when running parallelism of slow tests.

    Args:
        test_files_to_run (`List[str]`): The list of tests to run.
        json_output_file (`str`): The path where to store the built json map.
    
dpkd/transformers/utils/tests_fetcher.py