// When
            int opnum1 = bind.getOpnum();
            int opnum2 = bind.getOpnum();
            int opnum3 = bind.getOpnum();

            // Then
            assertEquals(opnum1, opnum2, "Opnum should be consistent");
            assertEquals(opnum2, opnum3, "Opnum should be consistent");
            assertEquals(0, opnum1, "All calls should return 0");
        }

        @Test

    class SamrCloseHandleTests {

        @Test
        @DisplayName("Should construct with correct opnum")
        void testConstructorAndOpnum() {
            // When: Creating close handle message
            samr.SamrCloseHandle message = new samr.SamrCloseHandle(mockPolicyHandle);

            // Then: Should have correct opnum and handle
            assertEquals(0x01, message.getOpnum());

    class SamrCloseHandleTests {

        @Test
        @DisplayName("Should construct with correct opnum")
        void testConstructorAndOpnum() {
            // When: Creating close handle message
            samr.SamrCloseHandle message = new samr.SamrCloseHandle(mockPolicyHandle);

            // Then: Should have correct opnum and handle
            assertEquals(0x01, message.getOpnum());

            // Simulate decoding some data
            buf.dec_ndr_long();
        }
    }

    @BeforeEach
    void setUp() {
        message = new TestDcerpcMessage(10); // Example opnum
    }

    @Nested
    @DisplayName("Flag Management Tests")
    class FlagManagementTests {

        @Test
        @DisplayName("isFlagSet should correctly identify set flags")
        void testIsFlagSet() {

        testSids = new jcifs.SID[] { mockSid };
        lookupSids = new MsrpcLookupSids(mockPolicyHandle, testSids);

        // Act
        int opnum = lookupSids.getOpnum();

        // Assert
        assertEquals(0x0f, opnum);
    }

    @Test
    void constructor_shouldPreservePolicyHandleReference() throws Exception {
        // Arrange
        jcifs.SID mockSid = mock(jcifs.SID.class);