why deprecated API ?

after flutter run
```
flutter run
Launching lib/main.dart on 2201116SG in debug mode...
Note: /home/mnotoone/.pub-cache/hosted/pub.dev/flutter_windowmanager-0.2.0/android/src/main/java/io/adaptant/labs/flutter_windowmanager/FlutterWindowManagerPlugin.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
```