@Test
  public void testLocalLoad() throws CacheException {
    final String name = getUniqueName() + "-ACK";
    final String objectName = "C";
    final Integer value = 44;
    remoteLoaderInvoked = false;
    loaderInvoked = false;
    vm0.invoke("Create ACK Region", () -> {
      remoteLoaderInvoked = false;
      loaderInvoked = false;
      try {
        RegionFactory<Object, Object> factory = getCache().createRegionFactory();
        factory.setScope(Scope.DISTRIBUTED_ACK);
        factory.setCacheLoader(new CacheLoader<Object, Object>() {
          @Override
          public Object load(LoaderHelper helper) {
            loaderInvoked = true;
            return value;
          }

          @Override
          public void close() {}
        });

        Region<Object, Object> region = createRegion(name, factory);
        region.create(objectName, null);

      } catch (CacheException ex) {
        fail("While creating ACK region", ex);
      }
    });

    vm1.invoke("Create ACK Region", () -> {
      remoteLoaderInvoked = false;
      loaderInvoked = false;
      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;
            return value;
          }

          @Override
          public void close() {}
        });

        createRegion(name, factory);
      } catch (CacheException ex) {
        fail("While creating ACK region", ex);
      }
    });

    vm0.invoke("Get a value from local loader", () -> {
      try {
        Object result = getRootRegion().getSubregion(name).get(objectName);
        assertThat(value).isEqualTo(result);
        assertThat(loaderInvoked).isEqualTo(Boolean.TRUE);
        assertThat(remoteLoaderInvoked).isEqualTo(Boolean.FALSE);

      } catch (CacheLoaderException | TimeoutException ignored) {
      }
    });
  }
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