assertThrows(NullPointerException.class, () -> {
            new MsrpcLookupSids(mockPolicyHandle, testSids);
        });
    }

    @Test
    void getOpnum_shouldReturnCorrectValue() {
        // Arrange
        jcifs.SID mockSid = mock(jcifs.SID.class);
        when(mockSid.unwrap(sid_t.class)).thenReturn(mockSidT);
        testSids = new jcifs.SID[] { mockSid };