code: public Set<Key> keySet(int access) {
  
  	Set<Key> set = new LinkedHashSet<Key>();
  	Map.Entry<Key, Member> entry;
  	Iterator<Entry<Key, Member>> it = _data.entrySet().iterator();
  	while (it.hasNext()) {
  	    entry = it.next();
  	    if (entry.getValue().getAccess() <= access) set.add(entry.getKey());
  	}
  	return set;
      }
docs: list of keys
  
  @param c
  @param access
  @param doBase
  @return key set