code: @Nonnull
      static String convertStringToAlphabet(@Nonnull final String string, @Nullable final Alphabet alphabet) throws IllegalArgumentException {
          return (alphabet != null) ? Decoder.encodeUTF16(string.toUpperCase(), alphabet.getNumber()) :
                  string.toUpperCase();
      }
docs: Convert a string into the same string using a different (or the same) alphabet.
  
  @param string   Any string.
  @param alphabet Alphabet to convert to, may contain Unicode characters.
  @return Converted mapcode.
  @throws IllegalArgumentException Thrown if string has incorrect syntax or if the string cannot be encoded in
  the specified alphabet.