def METHOD_NAME(
    input_dir: str | None = None,
    output_dir: str | None = None,
) -> None:
    """Set PUDL_INPUT and/or PUDL_OUTPUT env variables.
    Args:
        input_dir: if set, overrides PUDL_INPUT env variable.
        output_dir: if set, overrides PUDL_OUTPUT env variable.
    """
    if input_dir:
        os.environ["PUDL_INPUT"] = input_dir
    if output_dir:
        os.environ["PUDL_OUTPUT"] = output_dir