创建控制器实例:在非对象上调用成员函数getModule()

I want to test actions of the controller in the Unit test, as described here: yii controller action unit testing without selenium. Optional; I know that this is done by using functional tests. Just interesting to try this approach.

For that I need to create the controller instance:

$controller = new SomeController('SomeController', Yii::$app->getModule('somemodule'));

As a result of executing this code I get the error:

Fatal error: Call to a member function getModule() on a non-object in C:\projects\ais\tests\codeception\backend\unit\SomeControllerTest.php on line 27

How to create a controller instance in the Unit test (and in general)?