code: public void addRespondToURL(String label, String respondToURL) throws MalformedURLException {
  
      // Sanity check on the respondToURL
      // The requirement for the respondToURL is a REST POST call, so that means
      // only HTTP and HTTPS schemes.
      // Localhost is allowed as well as a valid response destination
      String[] schemes = { "http", "https" };
      UrlValidator urlValidator = new UrlValidator(schemes, UrlValidator.ALLOW_LOCAL_URLS);
      if (!urlValidator.isValid(respondToURL))
        throw new MalformedURLException("The probe respondTo URL is invalid: " + respondToURL);
  
      _probe.addRespondToURL(label, respondToURL);
  
    }
docs: Add a URL that specifies where the Responder should send the response.
  Provide a label as a hint to the Responder about why this URL was included.
  For example: give a "internal" label for a respondToURL that is only
  accessible from inside a NATed network.
  
  @param label - hint about the URL
  @param respondToURL - the URL the responder will POST a payload to
  @throws MalformedURLException if the URL is bad