code: public static Map<String, List<String>> deduplicateFormats(Format format) {
     Map<String, List<String>> res = new LinkedHashMap<>();
     mapAdd(res, format.short_, "SHORT");
     mapAdd(res, format.medium, "MEDIUM");
     mapAdd(res, format.long_, "LONG");
     mapAdd(res, format.full, "FULL");
     return res;
    }
docs: De-duplication of formats.