void getNetbiosName_null() {
        assertNull(ctx.getNetbiosName());
    }

    @Test
    @DisplayName("getSigningKey throws when ExtendedGSSContext not implemented")
    void getSigningKey_notImplementedByGSSContext() {
        SmbException ex = assertThrows(SmbException.class, () -> ctx.getSigningKey());
        assertTrue(ex.getMessage().contains("ExtendedGSSContext is not implemented"));
    }

    @Test