def METHOD_NAME(f):
    """
    A decorator that presents the calling dataset with a range index.
    This decorator facilitates writing methods that are agnostic to the
    true indices in a DataSet. Original index columns are preserved through
    wrapped function calls.
    """
    @wraps(f)
    def wrapped(ds, *args, **kwargs):
        names = ds.index.names
        ds = ds._index_from_names([None], inplace=True)
        result = f(ds, *args, **kwargs)
        result = result._index_from_names(names, inplace=True)
        ds = ds._index_from_names(names, inplace=True)
        return result.__finalize__(ds)
    return wrapped