call_user_func_array() expects parameter 1 to be a valid callback, class 'think\Collection' does not have a method 'css'

     * Specify data which should be serialized to JSON
     */
    public function jsonSerialize()
    {
        return $this->toArray();
    }

    public function __call($name, $arguments)
    {
        return call_user_func_array([$this->getCollection(), $name], $arguments);
    }

}