PHPUnit tests are failing with the following error for this patch: https://gerrit.wikimedia.org/r/#/c/177987/
15:59:14 Fatal error: Class Mock_BagOStuff_dbf9b0e9 contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (BagOStuff::cas) in /srv/deployment/integration/phpunit/vendor/phpunit/phpunit-mock-objects/PHPUnit/Framework/MockObject/Generator.php(231) : eval()'d code on line 452
Jenkins console: https://integration.wikimedia.org/ci/job/mwext-TwnMainPage-testextension-zend/9/console