How to use the configargparse.ArgumentDefaultsHelpFormatter function in ConfigArgParse

def test_executable_pathname(self):
        config_dir = os.path.join(uth.cakedir(), "ct.conf.d")
        config_files = [os.path.join(config_dir, "gcc.debug.conf")]
        cap = configargparse.getArgumentParser(
            description="TestNamer",
            formatter_class=configargparse.ArgumentDefaultsHelpFormatter,
            default_config_files=config_files,
            args_for_setting_config_path=["-c", "--config"],
            ignore_unknown_config_file_keys=True,
        )
        argv = ["--no-git-root"]
        ct.apptools.add_common_arguments(cap=cap, argv=argv, variant="gcc.debug")
        ct.namer.Namer.add_arguments(cap=cap, argv=argv, variant="gcc.debug")
        args = ct.apptools.parseargs(cap, argv)
        namer = ct.namer.Namer(args, argv=argv, variant="gcc.debug")
        exename = namer.executable_pathname("/home/user/code/my.cpp")
        self.assertEqual(exename, "bin/gcc.debug/my")

def test_multiple_parse_known_args(self):
        non_existent_config_files = ["/blah/foo.conf", "/usr/bin/ba.conf"]
        cap = configargparse.getArgumentParser(
            prog="UnitTest",
            description="unit testing",
            formatter_class=configargparse.ArgumentDefaultsHelpFormatter,
            default_config_files=non_existent_config_files,
            args_for_setting_config_path=["-c", "--config"],
        )

        cap.add(
            "--variant",
            help="Specifies which variant of the config should be used. Use the config name without the .conf",
            default="debug",
        )
        parsed_args = cap.parse_known_args()

        add_to_parser_in_func()

        cap.add(
            "-c",
            "--cfg",

def setUp(self):
        uth.reset()
        cap = configargparse.getArgumentParser(
            description="Configargparser in test code",
            formatter_class=configargparse.ArgumentDefaultsHelpFormatter,
            args_for_setting_config_path=["-c", "--config"],
            ignore_unknown_config_file_keys=False,
        )
        ct.headerdeps.add_arguments(cap)

def get_config(base_dir=''):
    """Get config from defaults, config file and/or parse arguments.

    Uses configargparse to allow argments to be set from a config file
    or via command line arguments.

      base_dir - set a specific base directory for file/path defaults.
    """
    p = configargparse.ArgParser(description='IIIF Image Testserver',
                                 default_config_files=[os.path.join(base_dir, 'iiif_testserver.cfg')],
                                 formatter_class=configargparse.ArgumentDefaultsHelpFormatter)
    add_shared_configs(p, base_dir)
    p.add('--container-prefix', default='',
          help="Container prefix seen by client to add to links generated")
    p.add('--scale-factors', default='auto',
          help="Set of tile scale factors or 'auto' to calculate for each image "
               "such that there are tiles up to the full image")
    p.add('--api-versions', default='1.0,1.1,2.0,2.1,3.0',
          help="Set of API versions to support")
    p.add('--manipulators', default='pil',
          help="Set of manipuators to instantiate. May be dummy,netpbm,pil "
               "or gen for generated image")
    p.add('--auth-types', default='none',
          help="Set of authentication types to support")
    p.add('--pages-dir', default=os.path.join(base_dir, 'testpages'),
          help="Test pages directory")
    p.add('--auth', action='store_true',

def __init__(self,
                 config_file_parser_class=configargparse.YAMLConfigFileParser,
                 formatter_class=configargparse.ArgumentDefaultsHelpFormatter,
                 **kwargs):
        """This funtion decides config parser and formatter
        
        Keyword Arguments:
            config_file_parser_class {configargparse.ConfigFileParser} -- config file parser (default: {configargparse.YAMLConfigFileParser})
            formatter_class {configargparse.ArgumentDefaultsHelpFormatter} -- config formatter (default: {configargparse.ArgumentDefaultsHelpFormatter})
        """
        
        self.parser = configargparse.ArgumentParser(
            config_file_parser_class=config_file_parser_class,
            formatter_class=formatter_class,
            **kwargs)

def get_config(base_dir=''):
    """Get config from defaults, config file and/or parse arguments.

    Uses configargparse to allow argments to be set from a config file
    or via command line arguments.

      base_dir - set a specific base directory for file/path defaults.
    """
    p = configargparse.ArgParser(description='IIIF Image API Reference Service',
                                 default_config_files=[os.path.join(base_dir, 'iiif_reference_server.cfg')],
                                 formatter_class=configargparse.ArgumentDefaultsHelpFormatter)
    add_shared_configs(p, base_dir)
    p.add('--scale-factors', default='auto',
          help="Set of tile scale factors or 'auto' to calculate for each image "
               "such that there are tiles up to the full image")
    p.add('--api-versions', default='1.0,1.1,2.0,2.1,3.0',
          help="Set of API versions to support")
    args = p.parse_args()

    if (args.debug):
        args.verbose = True
    elif (args.verbose):
        args.quiet = False

    # Split list arguments
    args.scale_factors = split_comma_argument(args.scale_factors)
    args.api_versions = split_comma_argument(args.api_versions)

def get_parser():
    parser = configargparse.ArgumentParser(
        description="ASR Decoding",
        config_file_parser_class=configargparse.YAMLConfigFileParser,
        formatter_class=configargparse.ArgumentDefaultsHelpFormatter,
    )

    # Note(kamo): Use '_' instead of '-' as separator.
    # '-' is confusing if written in yaml.
    parser.add_argument(
        "--config", is_config_file=True, help="config file path"
    )

    parser.add_argument(
        "--log_level",
        type=lambda x: x.upper(),
        default="INFO",
        choices=("INFO", "ERROR", "WARNING", "INFO", "DEBUG", "NOTSET"),
        help="The verbose level of logging",
    )

def get_parser():
    """Get parser of decoding arguments."""
    parser = configargparse.ArgumentParser(
        description='Synthesize speech from text using a TTS model on one CPU',
        config_file_parser_class=configargparse.YAMLConfigFileParser,
        formatter_class=configargparse.ArgumentDefaultsHelpFormatter)
    # general configuration
    parser.add('--config', is_config_file=True, help='config file path')
    parser.add('--config2', is_config_file=True,
               help='second config file path that overwrites the settings in `--config`.')
    parser.add('--config3', is_config_file=True,
               help='third config file path that overwrites the settings in `--config` and `--config2`.')

    parser.add_argument('--ngpu', default=0, type=int,
                        help='Number of GPUs')
    parser.add_argument('--backend', default='pytorch', type=str,
                        choices=['chainer', 'pytorch'],
                        help='Backend library')
    parser.add_argument('--debugmode', default=1, type=int,
                        help='Debugmode')
    parser.add_argument('--seed', default=1, type=int,
                        help='Random seed')

def parse():
    parser = configargparse.ArgumentParser(
        config_file_parser_class=configargparse.YAMLConfigFileParser,
        formatter_class=configargparse.ArgumentDefaultsHelpFormatter)
    parser.add('--config', is_config_file=True, help='config file path')
    parser.add('--config2', is_config_file=True, default=False, nargs='?',
               help='another config file path to overwrite --config')
    # general
    parser.add_argument('--corpus', type=str,
                        help='corpus name')
    parser.add_argument('--n_gpus', type=int, default=1,
                        help='number of GPUs (0 indicates CPU)')
    parser.add_argument('--model_save_dir', type=str, default=False,
                        help='directory to save a model')
    parser.add_argument('--resume', type=str, default=False, nargs='?',
                        help='model path to resume training')
    parser.add_argument('--job_name', type=str, default=False,
                        help='job name')
    parser.add_argument('--stdout', type=strtobool, default=False,
                        help='print to standard output during training')

def add_arguments(
        cls, parser: configargparse.ArgumentParser = None
    ) -> configargparse.ArgumentParser:
        assert check_argument_types()
        # NOTE(kamo): Use '_' instead of '-' to avoid confusion
        if parser is None:
            parser = configargparse.ArgumentParser(
                description="Train ASR",
                config_file_parser_class=configargparse.YAMLConfigFileParser,
                formatter_class=configargparse.ArgumentDefaultsHelpFormatter,
            )

        AbsTask.add_arguments(parser)
        group = parser.add_argument_group(description="Task related")

        # NOTE(kamo): add_arguments(..., required=True) can't be used
        # to provide --print_config mode. Instead of it, do as
        required = parser.get_default("required")
        required += ["token_list"]

        group.add_argument(
            "--token_list",
            type=str_or_none,
            default=None,
            help="A text mapping int-id to token",
        )