}

    @Test
    @DisplayName("send with multiple params returns the stubbed response")
    void send_withParams_returnsResponse() throws Exception {
        // Arrange
        when(tree.send(eq(request), eq(RequestParam.NO_TIMEOUT), eq(RequestParam.NO_RETRY))).thenReturn(response);

        // Act
        CommonServerMessageBlockResponse out = tree.send(request, RequestParam.NO_TIMEOUT, RequestParam.NO_RETRY);

    /**
     * @return true if the <b>debug</b> error level is enabled
     */
    boolean isDebugEnabled();

    /**
     * Send a message to the user in the <b>debug</b> error level.
     *
     * @param content
     */
    void debug(CharSequence content);

    /**
     * Send a message (and accompanying exception) to the user in the <b>debug</b> error level.<br>

```mermaid
sequenceDiagram
    participant App
    participant Client

    App->>App: Produce Item 1
    App->>Client: Send Item 1
    App->>App: Produce Item 2
    Client->>Client: Process Item 1
    App->>Client: Send Item 2
    App->>App: Produce Item 3
    Client->>Client: Process Item 2
    App->>Client: Send Item 3
    Client->>Client: Process Item 3
    Note over App: Keeps producing...
    Note over Client: Keeps consuming...

     */
    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;

    /**

    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").
    """

	go func() {
		wg.Wait()
		defer xioutil.SafeClose(send)
		err := m.handleRequests(ctx, msg, send, handler, handlerIn)
		if err != nil {
			handlerErr.Store(err)
		}
	}()

	// Response sender goroutine...
	go func(outBlock <-chan struct{}) {
		wg.Wait()
		defer m.parent.deleteMux(true, m.ID)
		m.sendResponses(ctx, send, c, &handlerErr, outBlock)
	}(m.outBlock)

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

# Request Body { #request-body }

When you need to send data from a client (let's say, a browser) to your API, you send it as a **request body**.

A **request** body is data sent by the client to your API. A **response** body is the data your API sends to the client.

This is normally called a **webhook**.

## Webhooks steps { #webhooks-steps }

The process normally is that **you define** in your code what is the message that you will send, the **body of the request**.

You also define in some way at which **moments** your app will send those requests or events.

                    response.b[response.off] = 42; // Return byte value 42
                }
                return null;
            }
        }).when(smbFile).send(any(SmbComReadAndX.class), any(SmbComReadAndXResponse.class));

        int result = smbRandomAccessFile.read();
        assertEquals(42, result);
        assertEquals(1, smbRandomAccessFile.getFilePointer());
    }