code: protected String responseToPid( final String responseText ) throws IOException {
          LOGGER.debug("responseToPid({})", responseText);
          if ( !isBlank(regex) ) {
              return responseText.replaceFirst(regex,"");
          } else if ( xpath != null ) {
              try {
                  return xpath( responseText, xpath );
              } catch (ParserConfigurationException | SAXException | XPathExpressionException e) {
                  throw new IOException(e);
              }
          } else {
              return responseText;
          }
      }
docs: Remove unwanted text from the minter service response to produce the desired identifier.
  Override this method for processing more complex than a simple regex replacement.
  @param responseText the response text
  @throws IOException if exception occurred
  @return the response