code: public static LocalFsClient create(Eventloop eventloop, Path storageDir, Object lock) {
  		return new LocalFsClient(eventloop, storageDir, Executors.newSingleThreadExecutor(), lock);
  	}
docs: Use this to synchronize multiple LocalFsClient's over some filesystem space
  that they may all try to access (same storage folder, one storage is subfolder of another etc.)