// 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,

            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),

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the
            external API with the notification of the invoice event
            (e.g. "payment successful").
    """

    }

    /**
     * Get the preferred size for send operations
     *
     * @return preferred send size in bytes
     */
    public int getPreferredSendSize() {
        return preferredSendSize;
    }

    /**
     * Set the preferred size for send operations
     *
     * @param preferredSendSize preferred send size in bytes
     */

     */
    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;

    /**

        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

        // 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

///

## Await for messages and send messages { #await-for-messages-and-send-messages }

In your WebSocket route you can `await` for messages and send messages.

{* ../../docs_src/websockets_/tutorial001_py310.py hl[48:52] *}

You can receive and send binary, text, and JSON data.

## Try it { #try-it }

        async with AsyncExitStack() as stack:
            scope[self.context_name] = stack

                log.warn("Failed to pre-allocate receive buffer", e);
            }
        }

        log.info("Initialized RDMA buffer pool with {} send and {} receive buffers", availableSendRegions.size(),
                availableReceiveRegions.size());
    }

    /**
     * Get a send region from the pool or allocate a new one
     *
     * @param minSize minimum required size
     * @return memory region for sending