code: public static ByteString quoteRegularExpression(byte[] unquoted) throws IOException {
      ByteString.Output output = ByteString.newOutput(unquoted.length * 2);
      writeQuotedRegularExpression(output, unquoted);
      return output.toByteString();
    }
docs: <p>quoteRegularExpression.</p>
  
  @param unquoted an array of byte.
  @return an array of byte.
  @throws java.io.IOException if any.