sclass Test_MultiSleeper {
  new MultiSleeper ms;
  
  void allTests {
    assertNull(ms.nextWakeUpTime());
    singleTask();
    singleTask();
  }
  
  void singleTask {
    new Flag flag;
    ms.doLater(new Timestamp().plusSeconds(0.5), flag);
    assertFalseVerbose("Not yet", flag.isUp());
    sleepSeconds(1);
    assertTrueVerbose(flag.isUp());
  }
}

svoid test_MultiSleeper() {
  new Test_MultiSleeper().allTests();

}