private TimerEvent getNextTimerEvent() {
    TimerEvent timerEvent = timerEventQueue.poll();
    Assert.assertNotNull(timerEvent);
    return timerEvent;
  }
Gets the next {@link TimerEvent} on the {@link #timerEventQueue}.

@return the next {@link TimerEvent}
jib-core/src/test/java/com/google/cloud/tools/jib/builder/TimerEventDispatcherTest.java