def combine_options(options=None):
    """ Returns the ``copy_options`` or ``format_options`` attribute with spaces in between and as
    a string. If options is ``None`` then return an empty string.

    Parameters
    ----------
    options : list, optional
        list of strings which is to be converted into a single string with spaces
        inbetween. Defaults to ``None``

    Returns
    -------
    str:
        ``options`` attribute with spaces in between
    """
    return " ".join(options) if options is not None else ""