@Override
  public void onSuccess(T result)
  {
    _future.complete(result);
  }
@Test
  public void testSuccess()
  {
    CompletableFuture<String> future = new CompletableFuture<>();
    CompletableFutureCallbackAdapter<String> adapter = new CompletableFutureCallbackAdapter<>(future);
    adapter.onSuccess("haha");
    assertTrue(future.isDone());
    assertFalse(future.isCompletedExceptionally());
    assertFalse(future.isCancelled());
    assertEquals(future.join(), "haha");
  }