code: private void createParent(Path path) throws IOException {
        Path parent = path.getParent();
        if (parent != null) {
            String key = pathToKey(makeAbsolute(parent));
            if (key.length() > 0) {
                store.storeEmptyFile(key + FOLDER_SUFFIX);
            }
        }
    }
docs: of the source does not vanish.