def _get_marker(query_id, page_number):
    """
        For a query_id, returns the marker at the end of the
        previous page. Returns a tuple of (marker, pages) where pages is
        the number of pages we had to go back to find the marker (this is the
        number of pages we need to skip in the result set)
    """

    counter = 1 - page_number
    pages_skipped = 0

    while counter > 0   :
        cache_key = _marker_cache_key(query_id, counter)
        ret = cache.get(cache_key)

        if ret:
            return ret, pages_skipped

        counter -= 1
        pages_skipped += 1

    # If we get here then we couldn't find a stored marker anywhere
    return None, pages_skipped
dataset/ETHPy150Open potatolondon/djangae/djangae/contrib/pagination/paginator.py/_get_marker/swapped operands of `-`