Refactor random number example to use NotifierProvider

examples/random_number/lib/main.dart

@@ -7,19 +7,20 @@ void main() {
   runApp(const ProviderScope(child: RandomNumberApp()));
 }
 
-// State notifier for generating a random number exposed by a state notifier
+// Notifier for generating a random number exposed by a state notifier
 // provider
-class RandomNumberGenerator extends Notifier<int>  {
+class RandomNumberGenerator extends Notifier<int> {
   @override
   int build() => Random().nextInt(9999);
-  
+
   void generate() {
     state = Random().nextInt(9999);
   }
 }
 
-// State notifier provider holding the state
-final randomNumberProvider = NotifierProvider(RandomNumberGenerator.new);
+// Notifier provider holding the state
+final randomNumberProvider =
+    NotifierProvider<RandomNumberGenerator, int>(RandomNumberGenerator.new);
 
 class RandomNumberApp extends StatelessWidget {
   const RandomNumberApp({super.key});