// 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
        dfsImpl = new DfsImpl(mockContext);
    }

    // Test for the constructor

        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(mockTransport.getDfsReferrals(any(), anyString(), anyString(), anyString(), anyInt())).thenReturn(null);