}
        if (off < 4) {
            throw new IOException("NetBIOS socket output buffer requires 4 bytes available before off");
        }

        off -= 4;

        b[off + 0] = (byte) SessionServicePacket.SESSION_MESSAGE;
        b[off + 1] = (byte) 0x00;
        b[off + 2] = (byte) (len >> 8 & 0xFF);
        b[off + 3] = (byte) (len & 0xFF);

        out.write(b, off, 4 + len);
    }

        // Test that the constructor correctly initializes the type and length fields.
        SessionRetargetResponsePacket packet = new SessionRetargetResponsePacket();
        assertEquals(SessionServicePacket.SESSION_RETARGET_RESPONSE, packet.type);
        assertEquals(6, packet.length);
    }

    @Test
    void writeTrailerWireFormatShouldReturnZero() {

import jcifs.NetbiosName;

/**
 * NetBIOS session request packet implementation.
 * This packet is used to initiate NetBIOS session connections.
 */
public class SessionRequestPacket extends SessionServicePacket {

    private final Name calledName, callingName;

    SessionRequestPacket(final Configuration config) {
        this.calledName = new Name(config);
        this.callingName = new Name(config);
    }

            }
            switch (sbuf[0] & 0xFF) {
            case SessionServicePacket.POSITIVE_SESSION_RESPONSE:
                if (LogStream.level >= 4) {
                    log.println("session established ok with " + address);
                }
                return;
            case SessionServicePacket.NEGATIVE_SESSION_RESPONSE:
                final int errorCode = in.read() & 0xFF;

            }
            switch (this.sbuf[0] & 0xFF) {
            case SessionServicePacket.POSITIVE_SESSION_RESPONSE:
                if (log.isDebugEnabled()) {
                    log.debug("session established ok with " + this.address);
                }
                return;
            case SessionServicePacket.NEGATIVE_SESSION_RESPONSE:
                final int errorCode = this.in.read() & 0xFF;