class Transaction { final String? id; final String? name; final String? date; final int? amount; final String? type; Transaction({this.id, this.name, this.date, this.amount, this.type}); Map toJson() { return { 'id': id, 'name': name, 'date': date, 'amount': amount, 'type': type, }; } factory Transaction.fromJson(Map json) { return Transaction( id: json['id'] as String?, name: json['name'] as String?, date: json['date'] as String?, amount: json['amount'] as int?, type: json['type'] as String?, ); } }