fail("Expected NullPointerException");
        } catch (NullPointerException e) {
            // Expected behavior when no listener is set
        }
    }

    @Test
    public void test_addShutdownListener_replacesExisting() {
        // Add first listener
        TestShutdownListener listener1 = new TestShutdownListener();
        scriptExecutor.addShutdownListener(listener1);

Shinsuke Sugaya <******@****.***> 1768400947 +0900