code: public byte[] decodeWebSafe(String s) throws Base64DecoderException {
      byte[] bytes = s.getBytes();
      return decodeWebSafe(bytes, 0, bytes.length);
    }
docs: Decodes data from web safe Base64 notation.
  Web safe encoding uses '-' instead of '+', '_' instead of '/'
  
  @param s the string to decode (decoded in default encoding)
  @return the decoded data