merge

lib/pages/user_search/user_serach.dart

@@ -17,7 +17,7 @@ Future<User?> searchUser(BuildContext context,
     );
 
 class UserSearchDelegate extends SearchDelegate<User> {
-  final OnUserSelect onUserSelect;
+  final OnUserSelect? onUserSelect;
   final bool popPage;
 
   UserSearchDelegate({required this.onUserSelect, required this.popPage});
@@ -119,7 +119,7 @@ class UserSearchDelegate extends SearchDelegate<User> {
 
   _onUserRowSelect(BuildContext context, User user) {
     if (onUserSelect != null) {
-      onUserSelect(user);
+      onUserSelect!(user);
     }
     if (popPage) {
       Navigator.pop(context);