@Override
  public FSDataOutputStream create(Path path, boolean overwrite, int bufferSize, short replication,
                                   long blockSize, Progressable progress) throws IOException {
    String confUmask = mAlluxioConf.getString(PropertyKey.SECURITY_AUTHORIZATION_PERMISSION_UMASK);
    Mode mode = ModeUtils.applyFileUMask(Mode.defaults(), confUmask);
    return this.create(path, new FsPermission(mode.toShort()), overwrite, bufferSize, replication,
        blockSize, progress);
  }
@Test
  public void concurrentInitialize() throws Exception {
    List<Thread> threads = new ArrayList<>();
    final org.apache.hadoop.conf.Configuration conf = getConf();
    for (int i = 0; i < 100; i++) {
      Thread t = new Thread(() -> {
        URI uri = URI.create(Constants.HEADER + "randomhost:410/");
        try {
          org.apache.hadoop.fs.FileSystem.get(uri, conf);
        } catch (IOException e) {
          fail();
        }
      });
      threads.add(t);
    }
    for (Thread t : threads) {
      t.start();
    }
    for (Thread t : threads) {
      t.join();
    }
  }