def _gen_param_excluder(added_kwargs):
    """
    Pass through all the original keys, but exclude any kwargs that we added
    manually through prep_scalar

    Parameters
    ----------
    added_kwargs : list of str

    Returns
    -------
    excluder : callable
    """

    def excluder(params, except_=None):
        """
        Parameters
        ----------
        params : dict
        except : str
        """
        return {k: v for k, v in params.items() if k not in added_kwargs or k == except_}

    return excluder