boolean treeContains(CoreInterface ci){
		if(ci.getClass() == Dvd.class){
			if(dvdTree.contains(ci)){
				return true;
			}
			return false;
		}else if(ci.getClass() == Location.class){
			if(locationTree.contains(ci)){
				return true;
			}
			return false;
		}else if(ci.getClass() == Genre.class){
			if(genreTree.contains(ci)){
				return true;
			}
			return false;
		}
		return false;
	}