static int dc_list_counter;

    private static NtlmChallenge interrogate(final NbtAddress addr) throws SmbException {
        final UniAddress dc = new UniAddress(addr);
        final SmbTransport trans = SmbTransport.getSmbTransport(dc, 0);
        if (USERNAME == null) {
            trans.connect();
            if (LogStream.level >= 3) {
                SmbTransport.log.println("""

    }

    @Test
    void testGetDc_Success() throws IOException, SmbAuthException {
        lenient().when(UniAddress.getByName("domain.com", true)).thenReturn(uniAddress);
        lenient().when(SmbTransport.getSmbTransport(uniAddress, 0)).thenReturn(smbTransport);

        DfsReferral referral = new DfsReferral();
        referral.server = "dc1.domain.com";
        referral.next = referral;

        when(mockConfig.isDfsDisabled()).thenReturn(false);
        when(mockContext.getTransportPool()).thenReturn(mockTransportPool);
        when(mockTransportPool.getSmbTransport(any(), anyString(), anyInt(), anyBoolean(), anyBoolean())).thenReturn(mockTransport);
        when(mockTransport.unwrap(any())).thenReturn(mockTransport);

        when(mockConfig.getDfsTtl()).thenReturn(300L);

        // Mock transport to throw IOException - simulating connection failure
        when(mockTransportPool.getSmbTransport(any(CIFSContext.class), anyString(), anyInt(), anyBoolean(), anyBoolean()))
                .thenThrow(new IOException("Connection failed"));

        // Instantiate the class under test

                        log.println("DFS redirect: " + dr);
                    }

                    final UniAddress addr = UniAddress.getByName(dr.server);
                    final SmbTransport trans = SmbTransport.getSmbTransport(addr, url.getPort());
                    /* This is a key point. This is where we set the "tree" of this file which
                     * is like changing the rug out from underneath our feet.
                     */