private static void verifyNoCacheLoaderLoads() throws Exception {
    Region region = cache.getRegion(REGION_NAME);
    ReturnKeyCacheLoader cacheLoader =
        (ReturnKeyCacheLoader) region.getAttributes().getCacheLoader();
    assertEquals(0/* expected */, cacheLoader.getLoads()/* actual */);
  }
unregister a key for a particular client in the server

@param clientId the client's ID
@param key the key it's no longer interest in
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/InterestListDUnitTest.java