### Question:
DubboFallbackRegistry { public static DubboFallback getConsumerFallback() { return consumerFallback; } private  DubboFallbackRegistry(); static DubboFallback getConsumerFallback(); static void setConsumerFallback(DubboFallback consumerFallback); static DubboFallback getProviderFallback(); static void setProviderFallback(DubboFallback providerFallback);  }### Answer:
@Test(expected = SentinelRpcException.class) public void testDefaultFallback() { BlockException ex = new FlowException("xxx"); DubboFallbackRegistry.getConsumerFallback() .handle(null, null, ex); }