public Value getValue(int index)
    {
        if (indexedValues == null)
            indexedValues = new ArrayList<Value>(values.values());

        return indexedValues.get(index);
    }
Disabled by default (the earlier protoc 2.x versions enabled this by default, but was changed later on).
protostuff-parser/src/main/java/io/protostuff/parser/EnumGroup.java