@Test
        @DisplayName("Should read valid structure with size 4")
        void testReadBytesWireFormatValidStructure() throws SMBProtocolDecodingException {
            // Given
            byte[] buffer = new byte[10];
            int bufferIndex = 0;
            SMBUtil.writeInt2(4, buffer, bufferIndex); // Write structure size = 4
            SMBUtil.writeInt2(0, buffer, bufferIndex + 2); // Reserved field

        assertEquals(0, bytesWritten);
    }

    @Test
    @DisplayName("Should handle error response structure size 9")
    void testReadBytesWireFormatErrorResponse() throws Exception {
        // Given
        byte[] buffer = new byte[256];
        int bufferIndex = 0;

        // Write structure size (9) - indicates error response
        SMBUtil.writeInt2(9, buffer, bufferIndex);

            int read = resp.readBytesWireFormat(buffer, start);

            // Assert
            assertEquals(4, read, "Should return the fixed structure size (4)");
        }

        @ParameterizedTest
        @ValueSource(ints = { 0, 1, 7 })
        @DisplayName("Throws when structure size is not 4")
        void throws_whenStructureSizeIsNotFour(int size) {
            // Arrange
            byte[] buffer = new byte[2];

    
    // Maximum channels per session
    public static final int DEFAULT_MAX_CHANNELS = 4;
    public static final int ABSOLUTE_MAX_CHANNELS = 32;
}
```

## 4. Data Structures

### 4.1 Network Interface Information
```java
package jcifs.internal.smb2.multichannel;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.ArrayList;
import java.util.List;

            try {
                Pac pac = new Pac(pacData, keys);
                assertNotNull(pac.getServerSignature());
                assertNotNull(pac.getKdcSignature());
            } catch (PACDecodingException e) {
                // Expected due to invalid logon info structure
                assertNotNull(e.getMessage());
            }

    @Test
    @DisplayName("Test wire format structure matches SMB2 specification")
    void testWireFormatStructure() {
        byte[] buffer = new byte[256];
        Arrays.fill(buffer, (byte) 0xCC); // Fill with pattern to detect unwritten areas

        int written = request.writeBytesWireFormat(buffer, 0);

        // Verify structure according to SMB2 FLUSH specification
        // Structure Size (2 bytes) - should be 24

            assertArrayEquals(testFileId, Arrays.copyOfRange(buffer, 8, 24));

            // Verify total bytes written (structure + lock data)
            assertEquals(24 + 24, bytesWritten); // 24 for structure, 24 for lock
        }

        @Test
        @DisplayName("Should write request structure correctly with multiple locks")
        void testWriteBytesWireFormatMultipleLocks() {

    @Test
    @DisplayName("Test readBytesWireFormat with valid structure size")
    void testReadBytesWireFormatValidStructureSize() throws Exception {
        response = new Smb2QueryDirectoryResponse(mockConfig, Smb2QueryDirectoryRequest.FILE_BOTH_DIRECTORY_INFO);

        byte[] buffer = new byte[512];
        int bufferIndex = 0;

        // Set structure size to 9 (valid)
        SMBUtil.writeInt2(9, buffer, bufferIndex);

import jcifs.smb1.dcerpc.ndr.NdrBuffer;
import jcifs.smb1.dcerpc.ndr.NdrException;

/**
 * Comprehensive test suite for SMB1 samr (Security Account Manager Remote) protocol
 * Tests all message types, data structures, and constants
 */
@ExtendWith(MockitoExtension.class)
@DisplayName("SMB1 SAMR Protocol Test Suite")
class samrTest {

    @Mock
    private NdrBuffer mockNdrBuffer;

    @Mock

This way, its schema will show up in the API docs user interface:

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses in Nested Data Structures { #dataclasses-in-nested-data-structures }

You can also combine `dataclasses` with other type annotations to make nested data structures.