return new Base16Encoding(alphabet);
    }
  }

  private static final class Base64Encoding extends StandardBaseEncoding {
    Base64Encoding(String name, String alphabetChars, @CheckForNull Character paddingChar) {
      this(new Alphabet(name, alphabetChars.toCharArray()), paddingChar);
    }

    private Base64Encoding(Alphabet alphabet, @CheckForNull Character paddingChar) {
      super(alphabet, paddingChar);