anchor.diff:            ..append(DeviceClass.audioCapture)
             ..append(DeviceClass.audioRender);
           final containsElement = vector.indexOf(DeviceClass.audioRender, pIndex);
  -        expect(containsElement, true);
  +        expect(containsElement, isTrue);
           expect(pIndex.value, equals(1));
         });
   
  
positive.code:           ..append('.jpeg')
            ..append('.png');
          final iterator = vector.first();
          expect(iterator.hasCurrent, true);
          expect(iterator.current, equals('.jpg'));
          expect(iterator.moveNext(), true);
          expect(iterator.current, equals('.jpeg'));
          expect(iterator.moveNext(), true);
          expect(iterator.current, equals('.png'));
          expect(iterator.moveNext(), false);
        });
  
        tearDown(() {
  
negative.code:           ..append('.jpg')
            ..append('.jpeg');
          final containsElement = vector.indexOf('.jpeg', pIndex);
          expect(containsElement, isTrue);
          expect(pIndex.value, equals(1));
        });
  
  