anchor.diff:      controller.animateTo(0.5, duration: const Duration(milliseconds: 100));
       expect(statusLog, equals(<AnimationStatus>[ AnimationStatus.completed ]));
       expect(controller.value, equals(0.5));
  +    controller.dispose();
     });
   
     test('Do not animate to upperBound if already at upperBound', () {
  
positive.code:     tick(const Duration(milliseconds: 40));
      expect(controller.lastElapsedDuration, equals(const Duration(milliseconds: 20)));
      controller.stop();
    });
  
    test('toString control test', () {
  
negative.code:     controller.animateTo(0.0, duration: const Duration(milliseconds: 100));
      expect(statusLog, equals(<AnimationStatus>[ AnimationStatus.completed ]));
      expect(controller.value, equals(0.0));
      controller.dispose();
    });
  
    test('Do not animate if already at target mid-flight (forward)', () {
  