if (hasntSeen(f)){
if (f != null && hasntSeen(f)){
	public Filterable filter(String fieldId, Filterable f) {		//log.info("Filtering Model "+f);				if (hasntSeen(f)){			//log.info("Haven't seen. Stepping into "+f);			enter(f);			addSeen(f);			f.acceptFilter(this);			exit(f);		} 				return f;// null;			}