def getSlice(size, endpoint_memo='', forwards=True):
    """Returns a slice of the results starting after endpoint_memo.

        Note that endpoint_memo should be a simple string and is untrusted.

        :param size: The maximum number of entries to return in the slice.
        :param endpoint_memo: An endpoint memo as returned by getEndpointMemos.
            If None or '', the edge of the results is used.
        :param forwards: If True, slice forwards from endpoint_memo. Otherwise
            slice backwards from endpoint_memo (e.g. ascending indices in the
            result will indicate earlier items in the results collection).
        :return: An object honouring the tuple protocol, just like 'results' in
            the IBatchNavigatorFactory constructor call. If forwards was not
            True, the order will be reversed vs the 'results' object, otherwise
            it is identical. The object should be fully materialized from any
            backing store and have no more than size elements in it.
        """
