code: static Clock getClock() {
      assert(engine.getCurrentTime() == clock.getTime()): 
      	   " Engine time = " + engine.getCurrentTime() + 
      	   " JobTracker time = " + clock.getTime();
      return clock;
    }
docs: Returns the simulatorClock in that is a static object in SimulatorJobTracker.
  
  @return SimulatorClock object.