@Override
      public void run() {
        loaderInvoked = false;
        remoteLoaderInvoked = false;
        remoteLoaderInvokedCount = 0;
        try {
          RegionFactory<Object, Object> factory = getCache().createRegionFactory();
          factory.setScope(Scope.DISTRIBUTED_ACK);
          factory.setCacheLoader(new CacheLoader<Object, Object>() {
            @Override
            public Object load(LoaderHelper helper) {
              remoteLoaderInvoked = true;
              remoteLoaderInvokedCount++;
              return null;
            }

            @Override
            public void close() {

            }
          });
          createRegion(name, factory);
        } catch (CacheException ex) {
          fail("While creating ACK region", ex);
        }
      }
Confirm that a netLoad that returns null will NOT allow other netLoad methods to be called.
geode-core/src/distributedTest/java/org/apache/geode/cache30/SearchAndLoadDUnitTest.java