null safety

example/pubspec.yaml

@@ -1,6 +1,9 @@
 name: flutter_app_badger_example
 description: Demonstrates how to use the flutter_app_badger plugin.
 
+environment:                                                      
+  sdk: '>=2.12.0 <3.0.0'
+
 dependencies:
   flutter:
     sdk: flutter

lib/flutter_app_badger.dart

@@ -15,7 +15,7 @@ class FlutterAppBadger {
   }
 
   static Future<bool> isAppBadgeSupported() async {
-    bool appBadgeSupported = await _channel.invokeMethod('isAppBadgeSupported');
-    return appBadgeSupported;
+    bool? appBadgeSupported = await _channel.invokeMethod('isAppBadgeSupported');
+    return appBadgeSupported ?? false;
   }
 }

pubspec.yaml

@@ -17,5 +17,5 @@ flutter:
         pluginClass: FlutterAppBadgerPlugin
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
   flutter: ">=1.10.0 <2.0.0"