when(mockConfig.isDfsDisabled()).thenReturn(true);
        DfsReferralData mockReferralData = mock(DfsReferralData.class);
        assertDoesNotThrow(() -> dfsResolver.cache(mockContext, "\\\\anyServer\\anyShare\\anyPath", mockReferralData));
    }

    @Test
    void testCache_InvalidPath() {
        when(mockConfig.isDfsDisabled()).thenReturn(false);

        @DisplayName("toString with null challenge throws NPE")
        void testToStringWithNullChallengeThrowsNPE() {
            UniAddress dc = mock(UniAddress.class);
            when(dc.toString()).thenReturn("ANYSERVER");

            NtlmChallenge nc = new NtlmChallenge(null, dc);

            // Hexdump.toHexString will throw NPE when accessing challenge.length
            assertThrows(NullPointerException.class, nc::toString);