public JObject ToJson()
{
var json = new JObject();
json["version"] = Version?.ToJson();
json["ownerID"] = OwnerId?.ToJson();
json["nonce"] = Nonce.ToBase64();
json["basicACL"] = BasicAcl;
json["attributes"] = new JArray(Attributes.Select(p => p.ToJson()));
json["placementPolicy"] = PlacementPolicy?.ToJson();
return(json);
}