public static function compositeGUIDs($models)
    {
        if (empty($models)) {
            return null;
        }
        if (!is_array($models) && $models instanceof static) {
            return $models->getGUID();
        }
        if (is_string($models) && strlen($models) == 16) {
            return $models;
        }
        $guids = [];
        foreach ($models as $model) {
            if ($model instanceof static) {
                $guids[] = $model->getGUID();
            } elseif (is_string($model)) {
                if (strlen($model) == 16) {
                    $guids[] = $model;
                } elseif (preg_match(Number::GUID_REGEX, $model)) {
                    $guids[] = Number::guid_bin($model);
                }
            }
        }
        return $guids;
    }