when(request.getSession()).thenReturn(session);

        ntlmServlet.service(request, response);

        ArgumentCaptor<NtlmPasswordAuthentication> authCaptor = ArgumentCaptor.forClass(NtlmPasswordAuthentication.class);
        verify(session).setAttribute(eq("NtlmHttpAuth"), authCaptor.capture());

        NtlmPasswordAuthentication capturedAuth = authCaptor.getValue();

        // Verify
        assertNull(result, "Authentication result should be null");

        // Capture the header value to verify its contents
        ArgumentCaptor<String> headerCaptor = ArgumentCaptor.forClass(String.class);
        verify(mockResponse).setHeader(eq("WWW-Authenticate"), headerCaptor.capture());
        String headerValue = headerCaptor.getValue();