@Override
  public void shutdown() {
    logger.info("Shutting down the Prioritization Manager.");
    running = false;
    try {
      shutDownLatch.await();
    } catch (Exception e) {
      logger.error("There was an error while waiting for shut down.", e);
    }
    logger.info("Shut down of the Prioritization Manager completed.");
  }
Shuts down the prioritization manager gracefully.
Sets {@link #running} to false
and waits until run method exits
ambry-prioritization/src/main/java/com/github/ambry/replica/prioritization/FileCopyDisruptionBasedPrioritizationManager.java