class Wallet { final double balance; final int id; final DateTime timestamp; Wallet({ required this.balance, required this.id, required this.timestamp, }); factory Wallet.fromJson(Map json) { return Wallet( balance: (json['balance'] ?? 0).toDouble(), id: json['id'], timestamp: (json['timestamp'] ?? json['timestmp']) != null ? DateTime.fromMillisecondsSinceEpoch( json['timestamp'] ?? json['timestmp']) : DateTime.now(), ); } Map toJson() { return { 'balance': balance, 'id': id, 'timestmp': timestamp.millisecondsSinceEpoch, }; } }