@Override
    public synchronized void afterWritingBytes() {
      try {
        if (cleared) {
          CacheObserverHolder.setInstance(null);
          // now that the flusher finished the async create of VALUE1 do another create
          region.create("KEY", "VALUE2");
          completedLatch.countDown();
        }
      } catch (AssertionError | Exception e) {
        errorCollector.addError(e);
      }
    }
Performs Region clear during DiskStore flush and then performs create after flushing.

<p>
TRAC #41770: ConcurrentRegionOperationsJUnitTest fails with duplicate create in an oplog
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/DiskRegionJUnitTest.java