map.put("キャ", new String[] { "kya" });
        map.put("キュ", new String[] { "kyu" });
        map.put("キョ", new String[] { "kyo" });

        map.put("シャ", new String[] { "sya", "sha" });
        map.put("シュ", new String[] { "syu", "shu" });
        map.put("ショ", new String[] { "syo", "sho" });
        map.put("シェ", new String[] { "sye", "she" });

        map.put("チャ", new String[] { "tya", "cha" });

        if (id.length() <= idPrefixLength) {
            return id;
        }
        return id.substring(0, idPrefixLength) + MessageDigestUtil.digest("SHA-256", id.substring(idPrefixLength));
    }

    /**
     * Extracts the URL from the target object using reflection.
     *
     * @param target The target object.