BatchHelper { public boolean isEmpty() { return pendingRequests.isEmpty(); } private  BatchHelper(
      HttpRequestInitializer requestInitializer,
      Storage gcs,
      long maxRequestsPerBatch,
      int numThreads); void queue(StorageRequest<T> req, JsonBatchCallback<T> callback); void flush(); boolean isEmpty();  }
@Test public void testIsEmpty() { Storage storage = new Storage(HTTP_TRANSPORT, JSON_FACTORY, httpRequestInitializer); BatchHelper batchHelper = batchFactory.newBatchHelper(httpRequestInitializer, storage, 2); assertThat(batchHelper.isEmpty()).isTrue(); }