public CompletableFuture<Result> getTerminationFuture() {
        return terminationFuture;
    }
@Test
    void testUnexpectedTaskManagerTerminationFailsRunnerFatally() throws Exception {
        final CompletableFuture<Void> terminationFuture = new CompletableFuture<>();
        final TestingTaskExecutorService taskExecutorService =
                TestingTaskExecutorService.newBuilder()
                        .setTerminationFuture(terminationFuture)
                        .build();
        final TaskManagerRunner taskManagerRunner =
                createTaskManagerRunner(
                        createConfiguration(),
                        createTaskExecutorServiceFactory(taskExecutorService));

        terminationFuture.complete(null);

        assertThatFuture(taskManagerRunner.getTerminationFuture())
                .eventuallySucceeds()
                .isEqualTo(TaskManagerRunner.Result.FAILURE);
    }