How to use the configargparse.ConfigFileParserException function in ConfigArgParse

items[key] = "true"
                continue

            key_value_match = re.match("^"+key+value+comment+"$", line)
            if key_value_match:
                key = key_value_match.group("key")
                value = key_value_match.group("value")

                if value.startswith("[") and value.endswith("]"):
                    # handle special case of lists
                    value = [elem.strip() for elem in value[1:-1].split(",")]

                items[key] = value
                continue

            raise ConfigFileParserException("Unexpected line {} in {}: {}".format(i,
                getattr(stream, 'name', 'stream'), line))
        return items

def _load_yaml(self):
        """lazy-import PyYAML so that configargparse doesn't have to dependend
        on it unless this parser is used."""
        try:
            import yaml
        except ImportError:
            raise ConfigFileParserException("Could not import yaml. "
                "It can be installed by running 'pip install PyYAML'")

        return yaml

def parse(self, stream):
        """Parses the keys and values from a config file."""
        yaml = self._load_yaml()

        try:
            parsed_obj = yaml.safe_load(stream)
        except Exception as e:
            raise ConfigFileParserException("Couldn't parse config file: %s" % e)

        if not isinstance(parsed_obj, dict):
            raise ConfigFileParserException("The config file doesn't appear to "
                "contain 'key: value' pairs (aka. a YAML mapping). "
                "yaml.load('%s') returned type '%s' instead of 'dict'." % (
                getattr(stream, 'name', 'stream'),  type(parsed_obj).__name__))

        result = OrderedDict()
        for key, value in parsed_obj.items():
            if isinstance(value, list):
                result[key] = value
            else:
                result[key] = str(value)

        return result

for config_key in self.get_possible_config_keys(action)}

        # open the config file(s)
        config_streams = []
        if config_file_contents is not None:
            stream = StringIO(config_file_contents)
            stream.name = "method arg"
            config_streams = [stream]
        elif not skip_config_file_parsing:
            config_streams = self._open_config_files(args)

        # parse each config file
        for stream in reversed(config_streams):
            try:
                config_items = self._config_file_parser.parse(stream)
            except ConfigFileParserException as e:
                self.error(e)
            finally:
                if hasattr(stream, "close"):
                    stream.close()

            # add each config item to the commandline unless it's there already
            config_args = []
            nargs = False
            for key, value in config_items.items():
                if key in known_config_keys:
                    action = known_config_keys[key]
                    discard_this_key = already_on_command_line(
                        args, action.option_strings, self.prefix_chars)
                else:
                    action = None
                    discard_this_key = self._ignore_unknown_config_file_keys or \