write config in current state, not in the initial state

        # set attributes from merged dictionary

        self.__dict__.update(cfg)

        # store the merged config for writing to file later

        self._yaml_dump = self._dump_yaml(cfg)

        # store keys from merged config for later writing to file

        self._keys_to_dump = list( cfg.keys() )

        # convert to Path

        self.input_path = Path(self.input_path).resolve().absolute()

        return cfg

    def to_file(self, outfile: str|Path):

        dict_to_dump = { k: v for k, v in self.__dict__.items() if k in self._keys_to_dump }

        yaml_dump = self._dump_yaml(dict_to_dump)

        with open(outfile, "w") as f:

            yaml.safe_dump(self._yaml_dump, f)

            yaml.safe_dump(yaml_dump, f, sort_keys=False)

    def _validate_file_cfg(self, cfg: dict, use_windows_codec_binaries: bool):

        """ensure configuration contains required keys"""