@VisibleForTesting
  String getCacheStats() {
    StringJoiner cacheStats = new StringJoiner("\n");
    cacheStats.add("========== CACHE STATS ==========");
    cacheStats.add(cache.describeStats());
    return cacheStats.toString();
  }
@Test
  public void testCacheStatsExist() {
    ManagedChannelFactory channelFactory = ManagedChannelFactory.createInProcess();
    BeamFnStatusClient client =
        new BeamFnStatusClient(
            apiServiceDescriptor,
            channelFactory::forDescriptor,
            mock(BundleProcessorCache.class),
            PipelineOptionsFactory.create(),
            Caches.fromOptions(
                PipelineOptionsFactory.fromArgs("--maxCacheMemoryUsageMb=234").create()));
    assertThat(client.getCacheStats(), containsString("used/max 0/234 MB"));
  }