public static ByteString valueOfBase64(final String s){
  if (s.length() == 0) {
    return EMPTY;
  }
  return Base64.decode(s);
}

public static ByteString valueOfBase64 ( final String s ) { if ( s . length ( ) == 0 ) { return EMPTY ; } return Base64 . decode ( s ) ; }
returns a byte string containing the base64 decoded bytes of the provided string .
