import 'package:json_annotation/json_annotation.dart'; part 'chat_message.g.dart'; @JsonSerializable() class ChatMessage { late MessageContent mssg; ChatMessage(); factory ChatMessage.fromJson(Map json) => _$ChatMessageFromJson(json); Map toJson() => _$ChatMessageToJson(this); } @JsonSerializable() class MessageContent { late String text; late String subj; late String time; MessageContent(); factory MessageContent.fromJson(Map json) => _$MessageContentFromJson(json); Map toJson() => _$MessageContentToJson(this); }