@Override
      public void afterHavingCompacted() {
        proceed = true;
        synchronized (OplogJUnitTest.this) {
          OplogJUnitTest.this.notify();
        }
      }
This tests the bug which caused the oplogRoller to attempt to roll a removed entry whose value
is Token.Removed This bug can occur if a remove operation causes oplog switching & hence roller
thread gets notified, & the roller thread obtains the iterator of the concurrent region map
before the remove
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/OplogJUnitTest.java