void cacheFullyQualifiedName()
    {
        final Boolean b = (Boolean) getOptions().get("allow_alias");
        if (b != null)
        {
            if (b.booleanValue())
                Collections.sort(sortedValues);
            else
                Collections.sort(sortedValues, Value.NO_ALIAS_COMPARATOR);
        }
        else if (ENUM_ALLOW_ALIAS)
            Collections.sort(sortedValues);
        else
            Collections.sort(sortedValues, Value.NO_ALIAS_COMPARATOR);

        final Proto proto = getProto();
        final String fullName = getFullName();

        proto.fullyQualifiedEnumGroups.put(fullName, this);

        if (!standardOptions.isEmpty())
            proto.references.add(new ConfiguredReference(standardOptions, extraOptions, fullName));

        for (Value v : values.values())
        {
            if (!v.field.standardOptions.isEmpty())
            {
                proto.references.add(new ConfiguredReference(
                        v.field.standardOptions, v.field.extraOptions, fullName));
            }
        }
    }
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