code: def get(self, path):
          
          key = tuple(map(id, path))
          item = self._cache.get(key, None)
          if item is None:
              logger.debug("Transform cache miss: %s", key)
              item = [0, self._create(path)]
              self._cache[key] = item
          item[0] = 0  # reset age for this item
  
          # make sure the chain is up to date
          #tr = item[1]
          #for i, node in enumerate(path[1:]):
          #    if tr.transforms[i] is not node.transform:
          #        tr[i] = node.transform
  
          return item[1]
docs: Get a transform from the cache that maps along *path*, which must
          be a list of Transforms to apply in reverse order (last transform is
          applied first).
  
          Accessed items have their age reset to 0.