@Test
  public void accessorTriggersCacheLoader() throws Exception {
    vm2.invoke(this::createPartitionedRegionWithCacheLoader);
    vm3.invoke(this::createPartitionedRegionWithCacheLoader);

    // create a "pure" accessor, no data storage
    Cache cache = getCache();

    PartitionAttributesFactory<String, String> partitionAttributesFactory =
        new PartitionAttributesFactory<>();
    partitionAttributesFactory.setRedundantCopies(1);
    partitionAttributesFactory.setLocalMaxMemory(0);

    RegionFactory<String, String> regionFactory =
        cache.createRegionFactory(RegionShortcut.PARTITION);
    regionFactory.setPartitionAttributes(partitionAttributesFactory.create());

    Region<String, String> region = regionFactory.create(regionName);

    assertThat(region.get(key1, cacheLoaderArg)).isEqualTo(cacheLoaderArg);
  }
This is a PartitionedRegion test for scope = D_ACK. 4 VMs are used to create the PR with and
without(Only Accessor) the DataStore.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/PartitionedRegionAPIDUnitTest.java