use fvm & change tween

.fvm/flutter_sdk

@@ -0,0 +1 @@
+/Users/akufe/fvm/versions/2.0.0

.fvm/fvm_config.json

@@ -0,0 +1,3 @@
+{
+  "flutterSdkVersion": "2.0.0"
+}

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "dart.flutterSdkPath": "/Users/akufe/fvm/versions/2.0.0"
+}

lib/src/animated_rotate.dart

@@ -28,7 +28,6 @@ class _AnimatedRoateState extends AnimatedWidgetBaseState<AnimatedRotate> {
 
   @override
   Widget build(BuildContext context) {
-    // return AnimatedOpacity()
     return Transform.rotate(
       angle: _rotateTween?.evaluate(animation) ?? 0,
       child: widget.child,
@@ -38,9 +37,9 @@ class _AnimatedRoateState extends AnimatedWidgetBaseState<AnimatedRotate> {
   @override
   void forEachTween(visitor) {
     _rotateTween = visitor(
-      _rotateTween,
+      _rotateTween!,
       widget.angle,
-      (dynamic value) => Tween<double>(begin: value),
+      (dynamic value) => Tween<double>(begin: value as double),
     ) as Tween<double>?;
   }
 }