// Prepare test data
        byte[] buffer = new byte[50];
        byte[] originalGuid = new byte[16];
        for (int i = 0; i < 16; i++) {
            originalGuid[i] = (byte) i;
        }
        System.arraycopy(originalGuid, 0, buffer, 4, 16);

        // Decode
        response.decode(buffer, 0, 24);

        // Get the server GUID

            when(decodeBuffer.dec_ndr_small()).thenReturn((int) originalSid.revision, (int) originalSid.sub_authority_count,
                    (int) originalSid.identifier_authority[0], (int) originalSid.identifier_authority[1],
                    (int) originalSid.identifier_authority[2], (int) originalSid.identifier_authority[3],