public CoreInterface getTreeObject(CoreInterface ci){
		if(ci.getClass() == Dvd.class){
			return dvdTree.get(ci);
		}else if(ci.getClass() == Location.class){
			return locationTree.get(ci);
		}else if(ci.getClass() == Genre.class){
			return genreTree.get(ci);
		}
		return null;
	}