public function dataStore($name)
    {
        if (gettype($name) == "string") {
            if (!isset($this->dataStores[$name])) {
                $this->dataStores[$name] = new DataStore;
            }
            return $this->dataStores[$name];
        } else {
            //$name's type is different from string
            //return everything for further process
            return $name;
        }
    }