@Override
          public void goingToFlush() {
            t2 = System.currentTimeMillis();
            delta = t2 - t1;
            LocalRegion.ISSUE_CALLBACKS_TO_CACHE_OBSERVER = false;
            synchronized (OplogJUnitTest.this) {
              OplogJUnitTest.this.notify();
            }
          }
Tests if buffer size & time are not set , the asynch writer gets awakened on time basis of
default 1 second
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/OplogJUnitTest.java