def decorateExternalMapping(original, external):
    """
        Decorate the externalized object mapping.

        :param original: The object that is being externalized. Passed
            to facilitate using non-classes as decorators.
        :param external: The externalization of that object, an
            :class:`~nti.externalization.interfaces.ILocatedExternalMapping`,
            produced by an implementation of
            :class:`~nti.externalization.interfaces.IInternalObjectExternalizer` or default rules.
        :return: Undefined.
        """
