toJson method
Implementation
Map toJson(){
Map result = {};
if (errorCode != null) result.addAll({"errorCode": errorCode});
if (localizedMessage != null) result.addAll({"localizedMessage": localizedMessage});
if (message != null) result.addAll({"message": message});
if (string != null) result.addAll({"string": string});
if (stackTrace != null) result.addAll({"stackTrace": stackTrace});
return result;
}