public void testLastContentChange() {
   TimeBase.setSimulated(10);
   AuState aus = new AuState(mau, historyRepo);
   aus.newCrawlStarted();
   TimeBase.step(10);
   aus.contentChanged();
   assertEquals(20, aus.getLastContentChange());
   TimeBase.step(10);
   aus.contentChanged();
   assertEquals(20, aus.getLastContentChange());
   TimeBase.step(10);
   aus.newCrawlFinished(1, "foo");
   TimeBase.step(10);
   aus.contentChanged();
   assertEquals(50, aus.getLastContentChange());
 }