def get(self):
        assert self.value is not None, "Instance not initialized"
        if self.cache is None:
            manager = DataManager.sharedManager()
            name = self._name
            self.cache = map(lambda e: manager.retrieve(name, e), self.value)

        return self.cache
    def get(self):
        if self.cache is None:
            if self.value is None:
                return None
            manager = DataManager.sharedManager()
            name = self._name
            self.cache = manager.retrieve(name, self.value)

        return self.cache