opt.: use json_serializable

lib/data/model/app/backup.g.dart

@@ -0,0 +1,35 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'backup.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+Backup _$BackupFromJson(Map<String, dynamic> json) => Backup(
+      version: (json['version'] as num).toInt(),
+      date: json['date'] as String,
+      spis: (json['spis'] as List<dynamic>)
+          .map((e) => ServerPrivateInfo.fromJson(e as Map<String, dynamic>))
+          .toList(),
+      snippets: (json['snippets'] as List<dynamic>)
+          .map((e) => Snippet.fromJson(e as Map<String, dynamic>))
+          .toList(),
+      keys: (json['keys'] as List<dynamic>)
+          .map((e) => PrivateKeyInfo.fromJson(e as Map<String, dynamic>))
+          .toList(),
+      container: json['container'] as Map<String, dynamic>,
+      history: json['history'] as Map<String, dynamic>,
+      lastModTime: (json['lastModTime'] as num?)?.toInt(),
+    );
+
+Map<String, dynamic> _$BackupToJson(Backup instance) => <String, dynamic>{
+      'version': instance.version,
+      'date': instance.date,
+      'spis': instance.spis,
+      'snippets': instance.snippets,
+      'keys': instance.keys,
+      'container': instance.container,
+      'history': instance.history,
+      'lastModTime': instance.lastModTime,
+    };