toJson method
Implementation
Map<String, dynamic> toJson() => {
if (ownPrivate != null) 'private': ownPrivate!.toJson(),
if (ownPublic != null) 'public': ownPublic!.toJson(),
if (latestOwnReceipt != null) 'latest': latestOwnReceipt!.toJson(),
'others': otherUsers.map((k, v) => MapEntry(k, v.toJson())),
};