code: private boolean processAttributeElement(HttpMessage message, int depth, String baseURL, Element element,
  			String attributeName) {
  		// The URL as written in the attribute (can be relative or absolute)
  		String localURL = element.getAttributeValue(attributeName);
  		if (localURL == null) {
  			return false;
  		}
  
  		processURL(message, depth, localURL, baseURL);
  		return true;
  	}
docs: Processes the attribute with the given name of a Jericho element, for an URL. If an URL is
  found, notifies the listeners.
  
  @param message the message
  @param depth the depth
  @param baseURL the base url
  @param element the element
  @param attributeName the attribute name
  @return {@code true} if a URL was processed, {@code false} otherwise.