private Set<TKey<?, ?>> setupDescriptionKeys() {
        Set<TKey<?, ?>> descriptionKeys = new HashSet<>();

        descriptionKeys.add(DatasetKeys.DISCIPLINE);
        descriptionKeys.add(DatasetKeys.LANGUAGE);
        descriptionKeys.add(DatasetKeys.SUBJECT);
        descriptionKeys.add(DatasetKeys.TIME_COVERAGE);
        descriptionKeys.add(DatasetKeys.SPATIAL_COVERAGE);
        descriptionKeys.add(DatasetKeys.ITEM_TYPE);
        descriptionKeys.add(DatasetKeys.COLLECTION_DESCRIPTION);

        validQualifiers.put(DatasetKeys.COLLECTION_DESCRIPTION, new HashSet<Class<? extends Enum<?>>>() {
            {
                add(DatasetQualifiers.LANGUAGE);
            }
        });

        return descriptionKeys;
    }