@Test
    @Order(2)
    public void submitTest() {
        final UpstreamCacheManager upstreamCacheManager = UpstreamCacheManager.getInstance();
        List<Upstream> upstreamList = new ArrayList<>(2);
        upstreamCacheManager.submit(SELECTOR_ID, upstreamList);
        upstreamList.add(Upstream.builder().url("url").status(true).build());
        upstreamList.add(Upstream.builder().status(true).build());
        upstreamCacheManager.submit(SELECTOR_ID, upstreamList);
        // hit `existUpstream.stream().filter`
        upstreamList.clear();
        upstreamList.add(Upstream.builder().url("url2").status(true).build());
        upstreamList.add(Upstream.builder().url("url").status(true).build());
        upstreamCacheManager.submit(SELECTOR_ID, upstreamList);
    }
The type UpstreamCacheManager check task test.
shenyu-loadbalancer/src/test/java/org/apache/shenyu/loadbalancer/cache/UpstreamCacheManagerTest.java