@Override
          public void run2() throws CacheException {

            Region region = getCache().getRegion(regionName);
            for (int i = 0; i < 100; i++) {
              if (i == 50) {
                IndexManager.testHook = new LocalTestHook();
              }
              region.put(i, new Portfolio(i));
              if (i == 50) {
                Wait.pause(20);
              }
            }
          }
This tests if index updates are blocked while region.clear() is called and indexes are being
reinitialized.
geode-core/src/distributedTest/java/org/apache/geode/cache/query/internal/index/ConcurrentIndexInitOnOverflowRegionDUnitTest.java