+
              Widget build(BuildContext context) {

+
                final animation = listenable as Animation<double>;

10

+
                return Center(

11

+
                  child: Container(

12

+
                    margin: const EdgeInsets.symmetric(vertical: 10),

13

+
                    height: animation.value,

14

+
                    width: animation.value,

15

+
                    child: const FlutterLogo(),

16

+
                  ),

17

+
                );

18

+
              }

19

+
            }