Save or update the private state needed by the cloud provider.

def _save_or_update(self):
        """Save or update the private state needed by the cloud provider.
        """
        with self._resource_lock:
            if not self._config or not self._config._storage_path:
                raise Exception("self._config._storage path is undefined")
            if not self._config._base_name:
                raise Exception("self._config._base_name is undefined")
            if not os.path.exists(self._config._storage_path):
                os.makedirs(self._config._storage_path)
            path = self._get_cloud_provider_storage_path()
            with open(path, 'wb') as storage:
                pickle.dump(self._config, storage, pickle.HIGHEST_PROTOCOL)
                pickle.dump(self._subscriptions, storage,
                            pickle.HIGHEST_PROTOCOL)