Sender.fromJson constructor
Implementation
factory Sender.fromJson(Map<String, dynamic> json) {
if (json['guest_id'] != null) json['user_id'] = json['guest_id'];
if (json['name'] != null) json['nickname'] = json['name'];
if (json['image'] != null) json['profile_url'] = json['image'];
return _$SenderFromJson(json)
..set(SendbirdChat().chat); // Set the singleton chat
}