class ImMessage {
  final String type;
  final String from;
  final String to;
  final String content;

  ImMessage({
    required this.type,
    required this.from,
    required this.to,
    required this.content,
  });

  Map<String, dynamic> toJson() => {
    'type': type,
    'from': from,
    'to': to,
    'content': content,
  };
}