我有一個簡單的單元測試來確保應用程序的主窗口是未修飾的：public class MainWindowUT extends AbstractMainWindowTest {    @Test    public void whenApplicationIsStarted_thenMainFrameIsUndecorated() {        @SuppressWarnings("boxing")        Boolean isUndecorated = GuiActionRunner.execute(() -> window.target().isUndecorated());        assertThat(isUndecorated).isTrue();    }}AbstractMainWindowTest 是：public abstract class AbstractMainWindowTest extends AssertJSwingJUnitTestCase {    protected FrameFixture window;    @Override    protected void onSetUp() {        ScaleRuler frame = GuiActionRunner.execute(() -> new ScaleRuler());        window = new FrameFixture(robot(), frame);        window.show();    }}ScaleRuler 是我的框架，目前什么都不做，只是 setUndecorated(true)。測試運行良好。如何從 Cucumber 執行相同的測試？public final class WindowAspectSteps {    @Then("the main window should be undecorated")    public void checkMainWindowIsUndecorated() {        //????    }}我試圖讓 WindowAspectSteps 擴展 AbstractMainWindowTest，但窗口變量仍然為空。