private static boolean isProactiveEvictionSweeperThreadStarted() throws Exception {
    ScheduledExecutorService service = retrieveSweeperExecutor();
    if (service == null) {
      return false;
    }
    return !service.isShutdown();
  }
Test cases for proactive LLAP cache eviction.
llap-server/src/test/org/apache/hadoop/hive/llap/cache/TestProactiveEviction.java