code: def PathList(self, pathlist):
          
          pathlist = self._PathList_key(pathlist)
          try:
              memo_dict = self._memo['PathList']
          except KeyError:
              memo_dict = {}
              self._memo['PathList'] = memo_dict
          else:
              try:
                  return memo_dict[pathlist]
              except KeyError:
                  pass
  
          result = _PathList(pathlist)
  
          memo_dict[pathlist] = result
  
          return result
docs: Returns the cached _PathList object for the specified pathlist,
          creating and caching a new object as necessary.