public static void sleep(long millis){
  if (mockSleepQueue == null) {
    sleepUninterruptibly(millis,TimeUnit.MILLISECONDS);
  }
 else {
    try {
      boolean isMultiPass=mockSleepQueue.take();
      rollMockClockMillis(millis);
      if (isMultiPass)       mockSleepQueue.offer(true);
    }
 catch (    InterruptedException e) {
    }
  }
}

public static void sleep ( long millis ) { if ( mockSleepQueue == null ) { sleepUninterruptibly ( millis , TimeUnit . MILLISECONDS ) ; } else { try { boolean isMultiPass = mockSleepQueue . take ( ) ; rollMockClockMillis ( millis ) ; if ( isMultiPass ) mockSleepQueue . offer ( true ) ; } catch ( InterruptedException e ) { } } }
sleep for a span of time , or mock sleep if enabled
