protected function removeCss($css)
    {
        $key=array_keys($this->data['css']['internal'],$css);
        if($key){
            array_splice($this->data['css']['internal'],$key[0],1);
        }

        $key=array_keys($this->data['css']['external'],$css);
        if($key){
            array_splice($this->data['css']['external'],$key[0],1);
        }
    }