feat: add new method

Author: LeoPaulJulie

packages/pillar-core/example/lib/repositories/example_repository.dart

@@ -4,6 +4,8 @@ import 'package:pillar_core/pillar_core.dart';
 abstract interface class ExampleRepository implements BaseRepository {
   /// Repository name
   Future<String> getData();
+  /// Clear cached data
+  Future<void> clearCache();
 }
 
 /// Implementation of ExampleRepository
@@ -17,4 +19,9 @@ class ExampleRepositoryImpl implements ExampleRepository {
     await Future<void>.delayed(const Duration(milliseconds: 500));
     return 'Sample data from repository';
   }
+
+  @override
+  Future<void> clearCache() {
+    return Future<void>.delayed(const Duration(milliseconds: 200));
+  }
 }