@Override
    public void close() {
        this.internalClient.close();
        ExecutorUtils.gracefulShutdown(5, TimeUnit.SECONDS, this.kubeClientExecutorService);
    }
@Test
    void testIOExecutorShouldBeShutDownWhenFlinkKubeClientClosed() {
        final ScheduledExecutorService executorService =
                Executors.newSingleThreadScheduledExecutor();
        final FlinkKubeClient flinkKubeClient =
                new Fabric8FlinkKubeClient(flinkConfig, kubeClient, executorService);
        flinkKubeClient.close();
        assertThat(executorService.isShutdown()).isTrue();
    }