// Stub tree send for varargs
        when(treeConnection.send(eq(resourceLoc), any(CommonServerMessageBlockRequest.class), isNull(), any(RequestParam[].class)))
                .thenReturn(resp);

        CommonServerMessageBlockResponse out = handle.send(req, RequestParam.NO_RETRY);
        assertSame(resp, out);

        assertFalse(it.hasNext(), "Iterator should be exhausted");

        // Close explicitly to exercise doCloseInternal
        it.close();

        // Verify interactions: one create, two additional directory queries (for fetchMore), one close
        verify(tree, times(1)).send(argThat((Request<?> r) -> r instanceof Smb2CreateRequest));

            when(mockFile.getType()).thenReturn(SmbConstants.TYPE_NAMED_PIPE);

            // th.send(request, response, ...) throws SmbException with NT_STATUS_PIPE_BROKEN
            doThrow(new SmbException(NtStatus.NT_STATUS_PIPE_BROKEN, false)).when(mockTree)
                    .send(any(jcifs.internal.CommonServerMessageBlockRequest.class),

        // Arrange: program send() to simulate first, next, next(NO_MORE_FILES)
        List<String[]> batches = new ArrayList<>();
        batches.add(new String[] { ".", "..", "a", "b" }); // first batch, dot entries filtered
        batches.add(new String[] { "c" }); // second batch
        batches.add(new String[] {}); // last -> NO_MORE_FILES

        // send() answer that mutates the provided response

    server.send(message3)
    clientListener.assertTextMessage(message3)

    // Empty client to server message.
    val message4 = ""
    client.send(message4)
    serverListener.assertTextMessage(message4)

    // Server to client message that shares context with message1.
    val message5 = message1 + message1
    server.send(message5)
    clientListener.assertTextMessage(message5)

        // Mock for ensureOpen to reopen file
        when(mockFile.openUnshared(anyInt(), anyInt(), anyInt(), anyInt(), anyInt())).thenReturn(mockFileHandle);

        when(mockTreeHandle.send(any(Smb2WriteRequest.class), any())).thenReturn(mockWriteResponse);
        when(mockWriteResponse.getCount()).thenReturn(1);

        outputStream = new SmbFileOutputStream(mockFile, mockTreeHandle, mockFileHandle,

     *            authentication). If false and the user has not been authenticated yet
     *            the client will be forced to send an authentication (server sends
     *            HttpServletResponse.SC_UNAUTHORIZED).
     * @return True if the negotiation is complete, otherwise false
     * @throws IOException if an I/O error occurs

    }
    
    /**
     * Establish RDMA connection
     */
    public abstract void connect() throws IOException;
    
    /**
     * Send data using RDMA
     */
    public abstract void send(ByteBuffer data, RdmaMemoryRegion region) throws IOException;
    
    /**
     * Receive data using RDMA  
     */
    public abstract ByteBuffer receive(int timeout) throws IOException;

        when(ioResp.getOutputData()).thenReturn(peek);

        when(tree.send(any(Smb2IoctlRequest.class), eq(RequestParam.NO_RETRY))).thenReturn(ioResp);

        // Act
        int available = stream.available();

        // Assert
        assertEquals(7, available, "Should return available bytes reported by server");

        // Interactions: ensure open, use tree, send IOCTL and close resources

     */
    int recv(byte[] buf, int off, int length) throws IOException;

    /**
     * Send data to the pipe
     *
     * @param buf buffer containing data to send
     * @param off offset in the buffer
     * @param length length of data to send
     * @throws IOException if an I/O error occurs
     */
    void send(byte[] buf, int off, int length) throws IOException;

    /**