@Override
    public Object run() throws ZuulException {
        RequestContext ctx = RequestContext.getCurrentContext();
        Throwable throwable = ctx.getThrowable();
        if (throwable != null) {
            if (!BlockException.isBlockException(throwable)) {
                // Trace exception for each entry and exit entries in order.
                // The entries can be retrieved from the request context.
                SentinelEntryUtils.tryTraceExceptionThenExitFromCurrentContext(throwable);
                RecordLog.info("[SentinelZuulErrorFilter] Trace error cause", throwable.getCause());
            }
        }
        return null;
    }
@Test
    public void testRun() throws Exception {
        SentinelZuulErrorFilter sentinelZuulErrorFilter = new SentinelZuulErrorFilter();
        Object result = sentinelZuulErrorFilter.run();
        Assert.assertNull(result);
    }