code: protected synchronized void startEvictor(long delay)
      {
          if (null != evictor)
          {
              evictor.cancel();
              evictor = null;
          }
          if (delay > 0)
          {
              evictor = new Evictor();
              EVICTION_TIMER.schedule(evictor, delay, delay);
          }
      }
docs: Start the eviction thread or service, or when
  <i>delay</i> is non-positive, stop it
  if it is already running.
  
  @param delay milliseconds between evictor runs.