assertNotNull(ex);
        assertEquals(message, ex.getMessage());
        assertNull(ex.getCause());
    }

    @Test
    @DisplayName("Should create SpnegoException with cause")
    void testWithCause() {
        // Given
        IllegalArgumentException cause = new IllegalArgumentException("bad arg");

        // When
        SpnegoException ex = new SpnegoException(cause);

        // Then