public ArrayList getArrayList(Object key) throws ClassCastException { return (ArrayList) get(key);
public ArrayList getArrayList(Object key)  { try { return (ArrayList) get(key); } catch (ClassCastException e) { throw new IllegalArgumentException("value to key is not an arraylist"); }
    public ArrayList getArrayList(Object key) throws ClassCastException {        return (ArrayList) get(key);        }