/** Adds the specified search result to the results list. */
  @Override
  public void addSearchResult(SearchResult result) {
    if (result.getUrn() == null) {
      // Some results can be missing a URN, specifically
      // secure results.  For now, we drop these.
      // We should figure out a way to show them later on.
      return;
    }

    LOG.debugf("Adding result urn: {0} EDT: {1}", result.getUrn(), EventQueue.isDispatchThread());
    allSearchResults.add(result);
  }
 @Override
 public int compare(SearchResult o1, SearchResult o2) {
   return o1.getUrn().compareTo(o2.getUrn());
 }