private static final int INPUTS_MASK = 0xFFF;

  enum EncodingOption {
    BASE64(BaseEncoding.base64()),
    BASE64_URL(BaseEncoding.base64Url()),
    BASE32(BaseEncoding.base32()),
    BASE32_HEX(BaseEncoding.base32Hex()),
    BASE16(BaseEncoding.base16());

    final BaseEncoding encoding;

    EncodingOption(BaseEncoding encoding) {
      this.encoding = encoding;
    }
  }