public CompletableFuture<Acknowledge> triggerSavepoint(
            AsynchronousJobOperationKey operationKey,
            String targetDirectory,
            SavepointFormatType formatType,
            TriggerSavepointMode savepointMode,
            Time timeout) {
        return registerOperationIdempotently(
                operationKey,
                () ->
                        triggerSavepointFunction.apply(
                                operationKey.getJobId(),
                                targetDirectory,
                                formatType,
                                savepointMode,
                                timeout));
    }
@Test
    public void throwsIfCacheIsShuttingDown() {
        savepointTriggerCache.closeAsync();
        assertThrows(
                IllegalStateException.class,
                () ->
                        handler.triggerSavepoint(
                                operationKey,
                                targetDirectory,
                                SavepointFormatType.CANONICAL,
                                TriggerSavepointMode.SAVEPOINT,
                                TIMEOUT));
    }