class Delegator:     # The cache is only used to be able to change delegates!     def __init__(self, delegate=None):        self.delegate = delegate        self.__cache = {}     def __getattr__(self, name):        attr = getattr(self.delegate, name) # May raise AttributeError        setattr(self, name, attr)        self.__cache[name] = attr        return attr     def resetcache(self):        for key in self.__cache.keys():            try:                delattr(self, key)            except AttributeError:                pass        self.__cache.clear()     def cachereport(self):        keys = self.__cache.keys()        keys.sort()        print keys     def setdelegate(self, delegate):        self.resetcache()        self.delegate = delegate     def getdelegate(self):        return self.delegate