LOG.error(ERR_FBS + o.getClass());
ErrorLog.error(BaseQueryFilter.class, E.FILTER_SCOPE + o.getClass());
  public Set filterByScope(Stem  ns, Set candidates) {    Set filtered = new LinkedHashSet();    Iterator iter = candidates.iterator();    while (iter.hasNext()) {      Object o = iter.next();      if      (o.getClass().equals(Group.class)) {        Group g = (Group) o;        if (StemFinder.isChild(ns, g)) {          filtered.add(g);        }      }      else if (o.getClass().equals(Stem.class)) {        Stem stem = (Stem) o;        if (StemFinder.isChild(ns, stem)) {          filtered.add(stem);        }      }      else {        LOG.error(ERR_FBS + o.getClass());      }    }    return filtered;  } // public Set filterByScope(ns, candidates)