`

    :param long_desc:   A detailed description of the option. Will be used by
                        `sos info`
    :type long_desc:    ``str``

    :param val_type:    The type of object the option accepts for values. If
                        not provided, auto-detect from the type of ``default``
    :type val_type:     A single type or a ``list`` of types
    r!