code: def Get(self, key):
      
      if key not in self._hash:
        raise KeyError(key)
  
      node = self._hash[key]
  
      self._age.Unlink(node)
      self._age.AppendNode(node)
  
      return node.data
docs: Fetch the object from cache.
  
      Objects may be flushed from cache at any time. Callers must always
      handle the possibility of KeyError raised here.
  
      Args:
        key: The key used to access the object.
  
      Returns:
        Cached object.
  
      Raises:
        KeyError: If the object is not present in the cache.