boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
    return schedulerService.awaitTermination(timeout, unit);
  }
Wait until this service has shutdown. Returns true if shutdown occurred within the timeout
and false otherwise.
<p>
This is currently exposed at the package private level for tests only.
samza-core/src/main/java/org/apache/samza/container/disk/PollingScanDiskSpaceMonitor.java