@Test
  public void concurrentDeleteTest() throws Exception {
    ConcurrentCreator concurrentCreator =
        new ConcurrentCreator(DEPTH, CONCURRENCY_DEPTH, ROOT_PATH);
    concurrentCreator.call();

    ConcurrentDeleter concurrentDeleter =
        new ConcurrentDeleter(DEPTH, CONCURRENCY_DEPTH, ROOT_PATH);
    concurrentDeleter.call();

    Assert.assertEquals(1, mMasterInfo.ls("/", true).size());
  }
  @Test
  public void concurrentDeleteTest() throws Exception {
    ConcurrentCreator concurrentCreator =
        new ConcurrentCreator(DEPTH, CONCURRENCY_DEPTH, ROOT_PATH);
    concurrentCreator.call();

    ConcurrentDeleter concurrentDeleter =
        new ConcurrentDeleter(DEPTH, CONCURRENCY_DEPTH, ROOT_PATH);
    concurrentDeleter.call();

    Assert.assertEquals(0, mFsMaster.getFileInfoList(new AlluxioURI("/"), true).size());
  }