def METHOD_NAME(self) -> dict:
    """Transform options object into a flat dictionary.
    Returns:
        dict: dictionary maps the namespace
    """
    def _flatten_dict(data: dict, path: str = "") -> dict:
        """Flatten a nested dictionary.
        Args:
            data (dict): input dictionary
            path (str, optional): basepath in the structure. Defaults to ''.
        Returns:
            dict: dictionary maps the namespace
        """
        output = dict()
        for key, value in data.items():
            if isinstance(value, dict):
                output.update(_flatten_dict(value, path=os.path.join(path, key)))
            else:
                if not key.startswith("_"):
                    output[os.path.join(path, key)] = value
        return output
    return _flatten_dict(self.to_dict())