assertDoesNotThrow(() -> filter.destroy());
    }

    @Test
    void testDoFilter_noAuthorizationHeader_shouldChallengeClient() throws Exception {
        // Initialize filter first
        initializeFilter();

        // Test request without Authorization header should challenge client
        when(request.getHeader("Authorization")).thenReturn(null);
        when(httpSession.getAttribute("NtlmHttpAuth")).thenReturn(null);