@Override
    protected Observable<Void> resumeWithFallback() {
        return RxReactiveStreams.toObservable(doFallback());
    }
@Test
    public void testResumeWithFallback() {
        MockServerWebExchange exchange = MockServerWebExchange.from(MockServerHttpRequest.get("http://localhost:8080/http")
                .remoteAddress(new InetSocketAddress(8092))
                .header("MetaDataCache", "Hello")
                .build());
        HystrixHandle hystrixHandle = new HystrixHandle();
        hystrixHandle.setGroupKey("groupKey");
        hystrixHandle.setCommandKey("commandKey");
        final HystrixCommandProperties.Setter propertiesSetter =
                HystrixCommandProperties.Setter()
                        .withExecutionTimeoutInMilliseconds((int) hystrixHandle.getTimeout())
                        .withCircuitBreakerEnabled(true)
                        .withExecutionIsolationStrategy(HystrixCommandProperties.ExecutionIsolationStrategy.SEMAPHORE)
                        .withExecutionIsolationSemaphoreMaxConcurrentRequests(hystrixHandle.getMaxConcurrentRequests())
                        .withCircuitBreakerErrorThresholdPercentage(hystrixHandle.getErrorThresholdPercentage())
                        .withCircuitBreakerRequestVolumeThreshold(hystrixHandle.getRequestVolumeThreshold())
                        .withCircuitBreakerSleepWindowInMilliseconds(hystrixHandle.getSleepWindowInMilliseconds());
        HystrixObservableCommand.Setter setter = HystrixObservableCommand.Setter
                .withGroupKey(HystrixCommandGroupKey.Factory.asKey(hystrixHandle.getGroupKey()))
                .andCommandKey(HystrixCommandKey.Factory.asKey(hystrixHandle.getCommandKey()))
                .andCommandPropertiesDefaults(propertiesSetter);
        assertThrows(NullPointerException.class, () -> {
            HystrixCommand hystrixCommand = new HystrixCommand(setter, exchange, mock(ShenyuPluginChain.class), null);
            TestSubscriber<Void> testSubscriberWithNull = new TestSubscriber<>();
            when(hystrixCommand.resumeWithFallback().subscribe(testSubscriberWithNull)).thenThrow(NullPointerException.class);
        });
    }