def METHOD_NAME(self, path: str) -> None:
    """Save the cost model to given file location.
    Parameters
    ----------
    path : str
        The file path.
    """
    import numpy as np  # type: ignore # pylint: disable=import-outside-toplevel
    np.METHOD_NAME(path, np.array(self.random_state, dtype=object), allow_pickle=True)