Recurring Error From SpinKitDoubleBounce  #127

Describe the bug
Spin kit throws error
"TypeError - Null check operator used on a null value " from the initstate -
Error thrown from -
double_bounce.dart in _SpinKitDoubleBounceState.initState at line 35 within flutter_spinkit
@OverRide
void initState() {
super.initState();

line 35 : _controller = (widget.controller ?? AnimationController(vsync: this, duration: widget.duration))
..addListener(() {
if (mounted) {
setState(() {});
}
})
SpinKit name
SpinKitDoubleBounce

environment:
sdk: ">=3.0.0 <4.0.0"

version -
flutter_spinkit: ^5.1.0