code: public static String decodeToString(InputStream in, String enc) throws IOException {
      return new String(decodeToBytes(in), enc);
    }
docs: Decode Base64 encoded data from the InputStream to a String. Characters that are not part of
  the Base64 alphabet are ignored in the input.
  
  @param in Stream from which to read data that needs to be decoded.
  @param enc Character encoding to use when converting bytes to characters.
  @return decoded data.
  @throws IOException if an IO error occurs.Throws:
  @throws UnsupportedEncodingException if the character encoding specified is not supported.
  @since ostermillerutils 1.02.16