@Override
 protected ArticleFiles createArticleFiles(CachedUrl cu) {
   String url = cu.getUrl();
   log.debug3("iterating url: " + url);
   Matcher mat = PATTERN.matcher(url);
   if (mat.find()) {
     return processFullTextPdf(cu, mat);
   }
   log.warning("Mismatch between article iterator factory and article iterator: " + url);
   return null;
 }
    @Override
    protected ArticleFiles createArticleFiles(CachedUrl cu) {
      String url = cu.getUrl();
      Matcher mat = ABSTRACT_PATTERN.matcher(url);
      if (mat.find()) {
        return processAbstract(cu, mat);
      }

      log.warning("Mismatch between article iterator factory and article iterator: " + url);
      return null;
    }
 /*
  * This is comlicated. MOST AUs have articles that live below and issue level TOC
  * that is,
  * <blah>/<journal_id>/vol#/iss#/ is a toc with no relevant metadata
  * <blah>/<journal_id>/vol#/iss#/xxx is an article with metadata
  * (eg Economist Voice V1)
  * BUT
  * in some AUs there are issues with only 1 article, in which case
  * <blah>/<journal_id>/vol#/iss#/ is an abstract with metadata
  * (eg Rhodes Cook V4)
  * and a few AUs with a mixture
  * (eg Forum for Health Economics V5)
  * So to identify ALL articles, we'll also have to capture issue level items and then look
  * at the html and if it has article metadata in it, count it as an article.
  *
  */
 @Override
 protected ArticleFiles createArticleFiles(CachedUrl cu) {
   String url = cu.getUrl();
   Matcher mat = pattern.matcher(url);
   if (mat.find()) {
     // we matched, but could this pattern potentially be a toc?
     Matcher tocmat = TOC_pattern.matcher(url);
     // if we could be a TOC then we must have metadata to be considered an article
     if (tocmat.find()) {
       if (hasArticleMetadata(cu)) {
         return processUrl(cu, mat);
       }
     } else {
       // we're not a potential TOC, so treat this as an article without checking
       return processUrl(cu, mat);
     }
     return null; // this was a TOC, not an article
   }
   log.warning("Mismatch between article iterator factory and article iterator: " + url);
   return null;
 }