Fix static test.

Author: nmalevanec

app/code/Magento/Reports/Model/ResourceModel/Order/Collection.php

@@ -3,7 +3,6 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-
 namespace Magento\Reports\Model\ResourceModel\Order;
 
 use Magento\Framework\DB\Select;
@@ -81,7 +80,7 @@ class Collection extends \Magento\Sales\Model\ResourceModel\Order\Collection
      * @param \Magento\Framework\Stdlib\DateTime\TimezoneInterface $localeDate
      * @param \Magento\Sales\Model\Order\Config $orderConfig
      * @param \Magento\Sales\Model\ResourceModel\Report\OrderFactory $reportOrderFactory
-     * @param null $connection
+     * @param \Magento\Framework\DB\Adapter\AdapterInterface $connection
      * @param \Magento\Framework\Model\ResourceModel\Db\AbstractDb $resource
      *
      * @SuppressWarnings(PHPMD.ExcessiveParameterList)