所以我有一個想要進行組件測試的方法，但我無法模擬注入類的已使用方法：測試方法class PageEventHandler{    public const PAGE_TYPE_PRODUCT_LIST = 'product_list';    ...    private $pagePublishValidator;    public function __construct(        ...        PagePublishValidator $pagePublishValidator    ) {        ...        $this->pagePublishValidator = $pagePublishValidator;    }    public function preUpdate(AbstractObject $object)    {        $this->pagePublishValidator->validate($object);    }}在publishValidator類中，我有一個我想模擬的方法getPrevious，它是一個trait的方法GetPrevious.php。publishValidator 類如下所示：驗證注入類的方法    public function validate(Page $object)    {        /** @var Page $previous */        $previous = $this->getPrevious($object);        var_dump('-----------------'); // <-- goes into here        if (!$previous) {            // a newly created object has no children            return;        }        var_dump('+++++++++++++++++++'); // <-- Does not go into here        var_dump('should go into here');    }測試用例public function testPreUpdateWithChildPageAndNewParent(){    $rootPage = $this->buildPage('', 'root');    $trait = $this->getMockBuilder(GetPrevious::class)        ->setMethods(['getPrevious'])        ->disableOriginalConstructor()        ->getMockForTrait();    $trait->expects($this->once())        ->method('getPrevious')        ->with($rootPage)        ->willReturn($rootPage); //Method called 0 times instead of one time, so mock seems to be wrong    $handler = new PageEventHandler(        $this->createAssertingMockProducer([], 0),        new NullProducer(),        new PagePublishValidator([PageEventHandler::PAGE_TYPE_PRODUCT_LIST])    );    $handler->preUpdate($rootPage);}