assertFalse(result.contains("\n"));
        }

        @Test
        @DisplayName("Should include stack trace when root cause exists")
        void testToStringWithRootCause() {
            String message = "Transport error";
            String rootMessage = "Root cause error";
            Exception rootCause = new IllegalArgumentException(rootMessage);

    /**
     * Verify that {@link #toString()} includes a stack trace when a root cause
     * is present.
     */
    @Test
    @DisplayName("toString with root cause contains stack trace")
    void testToStringWithRootCause() {
        RuntimeException cause = new RuntimeException("boom");
        SmbException ex = new SmbException(0, cause);