private void extractToMap(Map<String, WordField[]> result, LinkNeighborhood ln)
            throws MalformedURLException {
        String urlStr = ln.getLink().toString();
        WordField[] wordsArray = extract(ln, urlStr, false);
        if (wordsArray != null) {
            result.put(urlStr, wordsArray);
        }
    }
Extract the information from links as word in the URL, anchor and around links, and converts
it to an Instance object

@param linkNeighboors The LinkNeighborhood instances to be converted to Instance
@param features String[] pre-defined words
@return HashMap mapping url -> instance
ache/src/main/java/achecrawler/link/classifier/builder/LinkNeighborhoodWrapper.java