@Override
          public void run2() throws CacheException {
            assertNotNull(cache);
            // Test hook to make put wait after RE lock is released but before Gateway events are
            // sent.
            DistributedCacheOperation.SLOW_DISTRIBUTION_MS = 2000;

            Region region = cache.getRegion(SEPARATOR + "repRegion");
            Map testMap = new HashMap();
            testMap.put("testKey", "testValue1");
            region.putAll(testMap);

            assertEquals(1, region.size());
            assertEquals("testValue2", region.get("testKey"));
          }
This is similar to above test but for PartitionedRegion.
geode-wan/src/distributedTest/java/org/apache/geode/internal/cache/wan/misc/NewWANConcurrencyCheckForDestroyDUnitTest.java