toJson method
Implementation
Map<String, dynamic> toJson() => {
"product_id": productId == null ? null : productId,
"asset_id": assetId == null ? null : assetId,
"sort_id": sortId == null ? null : sortId,
"created_at": createdAt == null ? null : createdAt!.toIso8601String(),
"updated_at": updatedAt == null ? null : updatedAt!.toIso8601String(),
};