toJson method
Implementation
@override
Map<String, dynamic> toJson() => <String, dynamic>{
'user_id': userId,
'title': title,
'name': name,
'sticker_type': stickerType?.toJson(),
'needs_repainting': needsRepainting,
'stickers': stickers.map((item) => item.toJson()).toList(),
'source': source,
'@type': constructor,
};