public void testBase64UrlInvalidDecodings() {
    assertFailsToDecode(base64Url(), "+zzz", "Unrecognized character: +");
    assertFailsToDecode(base64Url(), "/zzz", "Unrecognized character: /");
  }

  public void testBase32() {
    // The following test vectors are specified in RFC 4648 itself
    testEncodingWithCasing(base32(), "", "");
    testEncodingWithCasing(base32(), "f", "MY======");