/**
  * Get the FileUpload (new one or current one)
  *
  * @param delimiter the delimiter to use
  * @return the InterfaceHttpData if any
  * @throws ErrorDataDecoderException
  */
 protected InterfaceHttpData getFileUpload(String delimiter) {
   if (decoder instanceof HttpPostMultipartRequestDecoder) {
     ((HttpPostMultipartRequestDecoder) decoder).getFileUpload(delimiter);
   }
   return null;
 }