Returns a serialized string representing the object, post-deduplication.

        :param o: the object

def dumps(self, o):
        """
        Returns a serialized string representing the object, post-deduplication.

        :param o: the object
        """
        f = io.BytesIO()
        VaultPickler(self, f).dump(o)
        f.seek(0)
        return f.read()