save method
Implementation
Future<void> save() async {
final json = <String, dynamic>{};
final p = <String, dynamic>{};
profiles.forEach((k, v) => p[k] = v.toJson());
json['profiles'] = p;
if (lastResults != null) json['lastResults'] = lastResults;
await file.writeAsString(JsonEncoder.withIndent(' ').convert(json));
}