def cache_scan(self):
        """
        Scan the lineage for the index of the most recent cache.
        :return: Index of most recent cache
        """
        try:
            return len(self.transformations) - self.transformations[::-1].index(CACHE_T)
        except ValueError:
            return 0
Scan the lineage for the index of the most recent cache.
        :return: Index of most recent cache