def __call__(toplevel, register):
    """Given the top-level object that is being copied, return the
        version of the adapted object that should be used in the new copy.

        Raising ResumeCopy means that you are foregoing the hook: the
        adapted object will continue to be recursively copied as usual.

        If you need to have a post-copy actions executed, register a
        callable with ``register``.  This callable must take a single
        argument: a callable that, given an object from the original,
        returns the equivalent in the copy.

        See README.txt for more explanation.
        """
