void forTestSignalSchedulingRun() throws InterruptedException {
      testLock.lock();
      try {
        schedulingTriggered = true;
        triggerSchedulingCondition.signal();
      } finally {
        testLock.unlock();
      }
    }
Note: this only works for testing the lack of invocations from the main thread.
llap-tez/src/test/org/apache/hadoop/hive/llap/tezplugins/TestLlapTaskSchedulerService.java