public function cache_widget($args, $content)
    {
        /**
         * Retrieve widget classname as cache key.
         *
         * @param string $classname
         * @return string $classname
         */
        wp_cache_set(
            $this->getModel()->getIdentifier(),
            [$args['widget_id'] => $content],
            'widget'
        );

        return $content;
    }