How to use the invoice2data.extract.loader.read_templates function in invoice2data

def setUp(self):
        self.templates = read_templates()
        self.parser = create_parser()

--------
    read_template : Function where templates are loaded
    InvoiceTemplate : Class representing single template files that live as .yml files on the disk

    Examples
    --------
    When using `invoice2data` as an library

    >>> from invoice2data.input import pdftotext
    >>> extract_data("invoice2data/test/pdfs/oyo.pdf", None, pdftotext)
    {'issuer': 'OYO', 'amount': 1939.0, 'date': datetime.datetime(2017, 12, 31, 0, 0), 'invoice_number': 'IBZY2087',
     'currency': 'INR', 'desc': 'Invoice IBZY2087 from OYO'}

    """
    if templates is None:
        templates = read_templates()

    # print(templates[0])
    extracted_str = input_module.to_text(invoicefile).decode("utf-8")

    logger.debug("START pdftotext result ===========================")
    logger.debug(extracted_str)
    logger.debug("END pdftotext result =============================")

    logger.debug("Testing {} template files".format(len(templates)))
    for t in templates:
        optimized_str = t.prepare_input(extracted_str)

        if t.matches_input(optimized_str):
            return t.extract(optimized_str)

    logger.error("No template for %s", invoicefile)

if args is None:
        parser = create_parser()
        args = parser.parse_args()

    if args.debug:
        logging.basicConfig(level=logging.DEBUG)
    else:
        logging.basicConfig(level=logging.INFO)

    input_module = input_mapping[args.input_reader]
    output_module = output_mapping[args.output_format]

    templates = []
    # Load templates from external folder if set.
    if args.template_folder:
        templates += read_templates(os.path.abspath(args.template_folder))

    # Load internal templates, if not disabled.
    if not args.exclude_built_in_templates:
        templates += read_templates()
    output = []
    for f in args.input_files:
        res = extract_data(f.name, templates=templates, input_module=input_module)
        if res:
            logger.info(res)
            output.append(res)
            if args.copy:
                filename = args.filename.format(
                    date=res["date"].strftime("%Y-%m-%d"),
                    invoice_number=res["invoice_number"],
                    desc=res["desc"],
                )

if args.debug:
        logging.basicConfig(level=logging.DEBUG)
    else:
        logging.basicConfig(level=logging.INFO)

    input_module = input_mapping[args.input_reader]
    output_module = output_mapping[args.output_format]

    templates = []
    # Load templates from external folder if set.
    if args.template_folder:
        templates += read_templates(os.path.abspath(args.template_folder))

    # Load internal templates, if not disabled.
    if not args.exclude_built_in_templates:
        templates += read_templates()
    output = []
    for f in args.input_files:
        res = extract_data(f.name, templates=templates, input_module=input_module)
        if res:
            logger.info(res)
            output.append(res)
            if args.copy:
                filename = args.filename.format(
                    date=res["date"].strftime("%Y-%m-%d"),
                    invoice_number=res["invoice_number"],
                    desc=res["desc"],
                )
                shutil.copyfile(f.name, join(args.copy, filename))
            if args.move:
                filename = args.filename.format(
                    date=res["date"].strftime("%Y-%m-%d"),