return buf;
    }

    // Helper: build an error body (without header) with structureSize=9
    private static byte[] buildErrorBody(int errorContextCount, int bc, byte[] errorData) {
        int bodyLen = 8 + bc; // 8 bytes fixed + variable data
        byte[] buf = new byte[bodyLen];
        SMBUtil.writeInt2(9, buf, 0); // structureSize
        buf[2] = (byte) errorContextCount; // ErrorContextCount

        // Assert
        assertEquals(expected, actual, "size() must be 8-byte aligned");
    }

    @ParameterizedTest
    @ValueSource(ints = { 0, 1, 5 })
    @DisplayName("writeBytesWireFormat writes StructureSize=4 and Reserved=0 at given offset")
    void writeBytesWireFormat_writesExpectedValuesAtOffset(int offset) {
        // Arrange
        Smb2LogoffRequest req = newRequest();

                        "Should throw SMBProtocolDecodingException for invalid structure size");

        assertEquals("Expected structureSize = 2", exception.getMessage());
    }

    @Test
    @DisplayName("Test readBytesWireFormat with zero structure size throws exception")
    void testReadBytesWireFormatZeroStructureSize() {

    @Override
    protected int readBytesWireFormat(final byte[] buffer, int bufferIndex) throws SMBProtocolDecodingException {
        final int start = bufferIndex;
        final int structureSize = SMBUtil.readInt2(buffer, bufferIndex);
        if (structureSize != 16) {
            throw new SMBProtocolDecodingException("Structure size is not 16");
        }

        this.shareType = buffer[bufferIndex + 2];
        bufferIndex += 4;

     */
    @Override
    protected int readBytesWireFormat(final byte[] buffer, final int bufferIndex) throws SMBProtocolDecodingException {
        final int structureSize = SMBUtil.readInt2(buffer, bufferIndex);
        if (structureSize != 4) {
            throw new SMBProtocolDecodingException("Structure size is not 4");
        }
        return 4;
    }

        final int start = bufferIndex;
        final int structureSize = SMBUtil.readInt2(buffer, bufferIndex);
        if (structureSize != 60) {
            throw new SMBProtocolDecodingException("Expected structureSize = 60");
        }
        this.closeFlags = SMBUtil.readInt2(buffer, bufferIndex + 2);
        bufferIndex += 4;

    @ValueSource(ints = { 0, 1, 2, 4, 8, 15, 17, 32, 64, 65535 })
    void testReadBytesWireFormatInvalidStructureSize(int structureSize) {
        // Given
        byte[] buffer = new byte[256];
        int offset = 0;

        // Write invalid structure size
        SMBUtil.writeInt2(structureSize, buffer, offset);

        // When & Then
        SMBProtocolDecodingException exception =

    @Override
    protected int readBytesWireFormat(final byte[] buffer, int bufferIndex) throws SMBProtocolDecodingException {
        final int start = bufferIndex;

        final int structureSize = SMBUtil.readInt2(buffer, bufferIndex);
        if (structureSize != 9) {
            throw new SMBProtocolDecodingException("Structure size != 9");
        }

        this.sessionFlags = SMBUtil.readInt2(buffer, bufferIndex + 2);

            assertEquals("Expected structureSize = 4", exception.getMessage());
        }

        @ParameterizedTest
        @ValueSource(ints = { 0, 1, 2, 3, 5, 6, 100, 65535 })
        @DisplayName("Should throw exception for various invalid structure sizes")
        void testReadBytesWireFormatVariousInvalidSizes(int structureSize) {
            byte[] buffer = new byte[1024];

        return size8(Smb2Constants.SMB2_HEADER_LENGTH + STRUCTURE_SIZE);
    }

    @Override
    protected int writeBytesWireFormat(byte[] dst, int dstIndex) {
        int start = dstIndex;

        // StructureSize (2 bytes) - must be 36
        SMBUtil.writeInt2(STRUCTURE_SIZE, dst, dstIndex);
        dstIndex += 2;

        // Reserved (2 bytes)
        SMBUtil.writeInt2(0, dst, dstIndex);
        dstIndex += 2;