GP_Translation::last_modified PHP Method

    public function last_modified($translation_set)
    {
        global $wpdb;
        $last_modified = wp_cache_get($translation_set->id, 'translation_set_last_modified');
        // Cached as "" if no translations.
        if ("" === $last_modified) {
            return false;
        } elseif (false !== $last_modified) {
            return $last_modified;
        }
        $last_modified = $wpdb->get_var($wpdb->prepare("SELECT date_modified FROM {$this->table} WHERE translation_set_id = %d AND status = %s ORDER BY date_modified DESC LIMIT 1", $translation_set->id, 'current'));
        wp_cache_set($translation_set->id, (string) $last_modified, 'translation_set_last_modified');
        return $last_modified;
    }