}

    @Nested
    @DisplayName("Input validation tests")
    class InputValidationTests {

        @Test
        @DisplayName("list with null root throws NullPointerException")
        void list_withNullRoot_throwsNpe() {
            // Intent: null root is invalid input
            assertThrows(NullPointerException.class, () -> SmbEnumerationUtil.list(null, "*", 0, null, null));
        }

        @Test