public function handleModel(Basic $model, $lang = null)
    {
        // Handle links to static items
        $items = $model->getSitemapItems($lang);
        if (is_array($items)) {
            // Foreach static model content
            foreach ($items as $item) {
                /* @var $item Basic|GoogleImage|GoogleAlternateLang|ActiveRecord */
                $this->handleItem($item, $lang);
            }
        }

        // Search models in db
        $query = $model->getSitemapItemsQuery($lang);
        if ($query instanceof \yii\db\Query) {
            // Foreach batch models
            $batchSize = static::getModelBatchSize($model);
            foreach ($query->each($batchSize) as $item) {
                /* @var $item Basic|GoogleImage|GoogleAlternateLang|ActiveRecord */
                $this->handleItem($item, $lang);
            }
        }
    }