public static function getSkuImageLinks($skuMetaId) {
        global $wpdb, $usces;

        $defaultres = [
            'fullSizeLink' => '',
            'thumbnailLink' => '',
        ];

        $data = $wpdb->get_row(
            $wpdb->prepare(
                "SELECT * FROM {$wpdb->postmeta} WHERE meta_id = %d AND meta_key = '_isku_'",
                (int)$skuMetaId
            ),
            ARRAY_A
        );

        if (empty($data)) {
            return $defaultres;
        }

        $skudata = unserialize($data['meta_value']);
        if (empty($skudata)) {
            return $defaultres;
        }

        $imgid = $usces->get_subpictid($skudata['code']);
        if (empty($imgid)) {
            $imgid = $usces->get_mainpictid($usces->getItemCode($data['post_id']));
        }

        $imgid = !empty($imgid) ? $imgid : 0;

        return [
            'fullSizeLink' => wp_get_attachment_image_src($imgid, 'full-size', true),
            'mediumSizeLink' => wp_get_attachment_image_src($imgid, 'medium', true),
            'thumbnailLink' => wp_get_attachment_image_src($imgid, 'thumbnail', true),
        ];
    }