* Oracle both implement a similar API to make an ExtendedGSSContext
         * available. That API is accessed via reflection to make this independent
         * of the runtime JRE
         */
        if (EXT_GSS_CONTEXT_CLASS == null || INQUIRE_SEC_CONTEXT == null || INQUIRE_TYPE_SESSION_KEY == null) {
            throw new SmbException("ExtendedGSSContext support not available from JRE");
        }

    }

    @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