resp.received = true;

        session.transport(); // initialise transport

        // Mock the sessionSetup behavior to avoid actual network calls
        // The sessionSetup method would normally send authentication messages
        // Only mark the sessionSetup response as received, not the actual request/response
        doAnswer(invocation -> {

        SMBUtil.writeInt4(0x00000001, buf, start + 16);
        // SessionId at +40 (sync header)
        SMBUtil.writeInt8(sessionId, buf, start + 40);
    }

    /**
     * Build a SESSION_SETUP response body with specified flags and security blob.
     * securityBufferOffset is set relative to header start.
     */