framework/data/ArrayDataProvider.php
protected function sortModels($models, $sort)
    {
        $orders = $sort->getOrders();
        if (!empty($orders)) {
            ArrayHelper::multisort($models, array_keys($orders), array_values($orders));
        }

        return $models;
    }
protected function sortModels($models, $sort)
    {
        $orders = $sort->getOrders();
        if (!empty($orders)) {
            ArrayHelper::multisort($models, array_keys($orders), array_values($orders));
        }

        return $models;
    }
Sorts the data models according to the given sort definition.
@param array $models the models to be sorted
@param Sort $sort the sort definition
@return array the sorted data models