import 'package:json_conversion_annotation/json_conversion_annotation.dart'; @JsonConversion() class SystemBean { String? version; SystemBean({this.version}); SystemBean.fromJson(Map json) { version = json['version']; } Map toJson() { final Map data = new Map(); data['version'] = this.version; return data; } static SystemBean jsonConversion(Map json) { return SystemBean.fromJson(json); } }