def register(cls, range_mixin):
        """
        Decorator for registering range set mixins for global use. This works
        the same as :meth:`~spans.settypes.MetaRangeSet.add`

        :param range_mixin: A :class:`~spans.types.Range` mixin class to
                            to register a decorated range set mixin class for
        :return: A decorator to use on a range set mixin class
        """

        def decorator(range_set_mixin):
            cls.add(range_mixin, range_set_mixin)
            return range_set_mixin
        return decorator
Decorator for registering range set mixins for global use. This works
        the same as :meth:`~spans.settypes.MetaRangeSet.add`

        :param range_mixin: A :class:`~spans.types.Range` mixin class to
                            to register a decorated range set mixin class for
        :return: A decorator to use on a range set mixin class