Workmanager：FutureCallback总是返回成功，无论结果如何

Question

我正在这样做：

val fileUploadRequest = OneTimeWorkRequestBuilder<FileUploadWorker>().build()

Futures.addCallback(workManager.enqueueUniqueWork(this::class.simpleName!!, ExistingWorkPolicy.KEEP, fileUploadRequest).result,
    object : FutureCallback<Operation.State.SUCCESS> {
        override fun onSuccess(result: Operation.State.SUCCESS?) {
            Log.d(TAG, "onSuccess: ")
        }

        override fun onFailure(t: Throwable) {
            Log.d(TAG, "onFailure: ")
        }
    },
    executor
)

使用此RXWorker代码：

override fun createWork(): Single<Result> {
        return Single.just(Result.failure())
}

我总是最终进入OnSuccess（）。怎么会？

另外：期货回调是否被删除了？还是永远活着？在某些情况下，我需要手动删除它吗？