* Encoded Data. Line feeds may be added using {@link #withSeparator(String, int)}.
   */
  public static BaseEncoding base64() {
    return BASE64;
  }

  private static final BaseEncoding BASE64_URL =
      new Base64Encoding(
          "base64Url()", "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_", '=');

  /**
   * The "base64url" encoding specified by <a