startAnims method
Implementation
@override
startAnims(List<AnimationController> controllers) {
var delays = [100, 200, 300, 400, 500];
for (var i = 0; i < controllers.length; i++) {
Future.delayed(Duration(milliseconds: delays[i]), () {
if (context.mounted) controllers[i].repeat(reverse: true);
});
}
}