anchor.diff:      var historyReplaceCalls = 0;
       var historyPushCalls = 0;
   
  -    ViewMock viewStatic = new ViewMock();
  -    ViewMock viewOneParameter = new ViewMock();
  +    ViewSpy viewStatic = new ViewSpy(new DummyView());
  +    ViewSpy viewOneParameter = new ViewSpy(new DummyView());
   
       PageNavigator pageNavigator = new PageNavigator(router, history);
       pageNavigator.registerView(routeNameStatic, viewStatic);
  
positive.code: 
        //then
        history.getLogs(callsTo("replaceState")).verify(happenedExactly(historyReplaceCalls));
        history.getLogs(callsTo("pushState")).verify(++historyPushCalls);
      });
  
      test('PageNavigator navigate to non existing site', () {
  
negative.code:       var pathOld = routeOneParameter.path(paramsOld);
        var pathNew = routeOneParameter.path(paramsNew);
  
        var view = new ViewSpy(new DummyView());
        var historyTest = new DummyTestHistory("", pathNew)
          ..test = false;
        var historyAsync = new AsyncHistoryMock(historyTest);
        var navigator = new PageNavigator(router, historyAsync);
  
        navigator.registerView(routeNameOneParameter, view);
  