// After negotiation, check if unicode capability is preserved
        assertTrue((response.getNegotiatedCapabilities() & SmbConstants.CAP_UNICODE) != 0);
    }

    @Test
    public void testIsValidWithInvalidDialect() {
        SmbNegotiationRequest request = mock(SmbNegotiationRequest.class);
        // Use reflection to set private dialectIndex field
        setDialectIndex(response, 11);