void resume() throws StoreException {
    hardDeleteLock.lock();
    try {
      if (paused.compareAndSet(true, false)) {
        startToken =
            startTokenBeforeLogFlush = startTokenSafeToPersist = endToken = index.revalidateFindToken(startToken);
        pauseCondition.signal();
      }
      logger.info("Hard delete resumed for {}", dataDir);
    } finally {
      hardDeleteLock.unlock();
    }
  }
Resumes hard deletes, if {@link #pause()} has been called prior to this.
ambry-store/src/main/java/com/github/ambry/store/HardDeleter.java