migrate chatty

packages/chatty/lib/domain/usecases/create_group_usecase.dart

@@ -7,9 +7,9 @@ import 'package:uuid/uuid.dart';
 
 class CreateGroupInput {
   CreateGroupInput({this.imageFile, this.name, this.members});
-  final File imageFile;
-  final String name;
-  final List<String> members;
+  final File? imageFile;
+  final String? name;
+  final List<String?>? members;
 }
 
 class CreateGroupUseCase {
@@ -23,7 +23,7 @@ class CreateGroupUseCase {
 
   Future<Channel> createGroup(CreateGroupInput input) async {
     final channelId = Uuid().v4();
-    String image;
+    String? image;
     if (input.imageFile != null) {
       image = await _uploadStorageRepository.uploadPhoto(
           input.imageFile, 'channels/$channelId');